[OSM-talk] Map rendering, which is not aligned to coordinate axes

[Holger Schöner]

Hi,

> On Wed, 2009-07-15 at 16:06 -0400, simon at mungewell.org wrote:
> > Holger Schöner:
> > > Cutting and rotating a "normal" map would of course not be
> > > appropriate, because (beside possible loss of quality) the labels
> > > would not be horizontal
> > > any more ...
> >
> > If you were working in an SVG frame work you could rotate the whole
> > image then apply a reverse rotation limited to just the labels after
> > the map was rendered.
> >
> > I also think that there is a osmarender 'parameter' which can set the
> > rotation on each element, so you could set this prior to rendering in
> > your rules file.
> >
> > You can use osmosis to cut a bounding polygon out of OSM data, this
> > might help you limit the plot to that of a rotated rectangle (or other
> > shape).
> > http://wiki.openstreetmap.org/wiki/Osmosis/DetailedUsage#--bounding-pol
> >ygon_.28--bp.29
> >
> > You don't say what the required graphic format is (SVG, PNG, tiles,
> > etc). Does osmarender provided suitable output for you?
> >
> > Simon.

In the moment, this is just an idea, and I am thinking about the best way to 
do something like this. So I am not (yet) dependent on any special renderer. 
(The cutting would not be a problem at all, using e.g. osmosis, as gary has 
written.)

Usually, I am using PostGIS/mapnik. So in principle, SVG would be an option 
as output (although I have not yet tried that for anything but very simple 
styles). It would of course depend on whether the transformations are 
manageable. But as far as I remember, the text is rendered as single letters 
by mapnik, so in reality that probably is no option.

-- 
Holger Schoener		numenor at ancalime.de