Mapnik Metawriters

Hermann Kraus

Details about the talk:
Metawriters are a new Mapnik feature that outputs information about where Mapnik has placed a certain feature. This data contains the actual area the symbol/text occupies (not only the position it was intended to go to) and any database fields can be added, too. This is especially important when new Mapnik features like dynamic text placement are used. One therefore can easily show additional information about the user's
selection. This mechanism is not tied to a single output format, but only a few functions have to be added to support a new format. A sample implementation for tiled JSON is provided.

I will talk about the following topics:
- Basic usage (including it in your rendering scripts)
- Possible applications
- Usage with dynamic text placement
- Adding new output formats
- Live demo (including dynamic text placement)
- Short introduction to Google Summer of Code (which sponsored this feature)

Details about the speaker:
I'm studying physics at the Universität Regensburg and I've worked on some open source projects.
- OpenStreetMap
- Mapnik
- Scribus
- Bazaar
As a hobby I build electronic devices which included building my own GPS unit and discovering OSM that way.

Theme: tech