re: gtk & gis

[Thomas Stover <thomas wsinnovations com>]

 Date: Thu, 11 Jun 2009 15:36:31 +0200
> From: Andrea Zagli <azagli inwind it>
> Subject: gtk & gis
> To: gtk-app <gtk-app-devel-list gnome org>
> Message-ID: <20090611153631 146644e2qf6bkklc saetta homelinux org>
> Content-Type: text/plain; charset=UTF-8; DelSp="Yes"; format="flowed"
>
> do you know some widget that can display maps (from shp or postgis)  
> and also allows very simple editing?
>
> on google i found only (old) widgets without editing
>
> thanks in advance
>
>
>   

I have helped a client make their own library. It uses cairo for all the 
output (not just for gtk). Cairo really is the magic that makes all the 
vectors and alpha blending so darn awesome. Some libraries that are 
excellent you can look into for building blocks are:

-proj4 (cartographic projection) (everything uses this behind the 
scenes, but no one mentions it)
-shapelib (most gis data is in or can be in shape files)
-netcdf (things like weather radar overlays)
-imagemagick (work with other non-png image formats for just cairo 
outside of gtk)
-libcurl w/ glib bindings or libsoup for http data

some other sources of data:
-yahoo maps is kinda hackable and is ok for internal use (google maps 
wants you to only use it for externally reachable sites)
-www.gisdatadepot.com

more usa specific:
-weather.gov
-usgs.gov

for academia (and through other pay sites):
-http://www.unidata.ucar.edu/software/ldm/ (live scientific data of 
several kinds)


All this is 2D, but it suites our needs very well. There is of course 
the http://grass.osgeo.org/ project which has many links and information 
for this area.

I'm still looking for a simple open source library for some basic 
astronomical features like where the sunlight is, etc.