Now that Google Summer of Code is over I'd like to show you some of theresults:
I already posted information about the newtext placement system. No big changes happened here, just a fewbugfixes. I also added some testsand reference images.
Improving text formating was the second half of my project.
Currently when you want to label a peak like thisName
you define these two symbolizers:The image will look like this:
This usually works, but it has some limitations. For example let's see what happens when the name gets a little longer:
Mapnik breaks the long name and the elevation disappears, because the offset is not correct.
Now let's have a look at how it is done with the new placement system:You only define one TextSymbolizer but with a different syntax:(Note: is the XML encoding of a newline character)
As you can see Mapnik automatically takes care of correct line spacing, no need to calculate offsets manually.
Backwards incompatible changes
To make this work some backwards incompatibilities had to be introduced.
Parameters you can change
You can change the following text attributes with the Format instruction:
But you are not limited to using a fixed format. You can implement your own class in C++ to do the formating. It's very simple:In the same way you can do custom text formating:
The code is ready, now it's required to test it on larger styles to find any remaining bugs. Python bindings also have to be updated to fully support the new features. When this is done the code will be released as Mapnik 2.1 as it's to late in the release cycle to include it in Mapnik 2.0.