[OSGeo-Discuss] Proposal: OSGeo Cartographic Library

[Ari Jolma]

Markus Neteler kirjoitti:
> Dear OSGeo,
>
> I would like to launch the idea of an "OSGeo Cartographic Library" to
> share concepts, source code and regression tests:
>
> http://wiki.osgeo.org/wiki/OSGeo_Cartographic_Library
>   

I proposed a year ago to develop a geospatial graphics library based on 
Cairo 
http://www.intevation.de/pipermail/freegis-list/2007-April/003142.html

I'm still very much interested in this. Cairo would provide a single API 
to render to an image buffer, on PDF and others. It has good support for 
rendering text with various fonts and there are high-level language APIs.

Currently Cairo can be used in Geoinformatica to render geodata, 
legends, etc. on a map. I'm already using that a bit and will use it 
much more in the future.

What I think is needed first, and would be the core content of the 
library is 1) a mapping of style information into Cairo commands, 2) 
capability to render cartographic symbols on maps, and 3) a mechanism to 
allow plugins that add legends etc. on the map, 4) symbol and label 
placement algorithms. Second need would perhaps be support for various 
geovisualization methods.

1) is rather straight-forward, I guess, using OGC Styled Layers standard
2) I'm not sure, there seems to be free resources like 
http://pubs.usgs.gov/of/1999/of99-430/ which offer symbols in EPS -- I 
don't find support in Cairo to render EPS on surfaces
3) is rather straight-forward
4) start from simple and existing codes

Cairo is of course just one technology and not suited for all needs in 
this domain. Furthermore, the data provider can be made separate from 
the library, but I'd like to start with and use GDAL (OGR in fact) as 
the default.

Anyway, I'd like to finally get going with this and start drafting an 
API. Any ideas how to proceed? Set up a svn repository somewhere?

Regards,

Ari

-- 
Prof. Ari Jolma
Geoinformatiikka / Geoinformatics
Teknillinen Korkeakoulu / Helsinki University of Technology
tel: +358 9 451 3886 address: POBox 1200, 02015 TKK, Finland
Email: ari.jolma at tkk.fi URL: http://www.tkk.fi/~jolma