Support for Google Maps encoded geometries

[Robert Coup]

When displaying polygons and polylines with GMaps, performance can be massively improved by using encoded geometries. It would be great for GeoDjango to support this:

• a module to encode geometries and return a dictionary, so people can JSON-encode and send to the client, embed in templates, etc.
• use encoded geometries in GoogleGeoAdmin

Resources:

• ​http://code.google.com/apis/maps/documentation/polylinealgorithm.html -- official docs
• ​http://facstaff.unca.edu/mcmcclur/GoogleMaps/EncodePolyline/ -- detailed discussion, examples, links to implementations in various languages
• ​http://wyattbaldwin.com/2007/04/19/google-maps-encoded-polylines/ -- Python implementation. GPLv3 licensed, and code isn't tidy.

[Robert Coup]

I've built a Python port of Mark McClure's ​Javascript encoder. There's also a matching C extension which has the same signature (think cStringIO vs StringIO). Other upsides: clean, pythonic, BSD licensed, unit tests. :)

Will be on Google Code somewhere in the next few days, or part of the ​gmaps-utility-library project.

[Robert Coup]

Now up at ​http://code.google.com/p/py-gpolyencode/

[Aymeric Augustin]

Change UI/UX from NULL to False.

[Aymeric Augustin]

Change Easy pickings from NULL to False.

[Aymeric Augustin]

This ticket has a large scope, the problems it describes are covered by an external library, and I don't see a good reason to merge it in Django.