Summary
In this chapter, we have explored the Mapnik map-generation toolkit in depth. We learned the following:
Mapnik is a powerful and flexible toolkit for generating a variety of maps
Mapnik uses the painter's algorithm to draw the various parts of a map in the correct order
A map is made up of multiple layers
Map rendering is controlled using styles
Styles are defined within the map and are referred to by the layers, allowing styles to be shared between map layers
Each style consists of one or more rules
Each rule has a list of symbolizers, telling Mapnik how to draw the layer's features onto the map, and an optional filter which selects the features the rule applies to
You can use a map definition file as a simpler way of creating maps without having to define all the symbolizers, filters, rules, styles, and layers in Python
You can use a map definition file as a stylesheet, separating the logic of building a map from the way it is formatted, in the same way that an HTML templating engine separates...
