[Vala] Setting prefix and paths at configure time.

["Federico Pelloni" <federico pelloni gmail com>]

In my project I need to load some custom pixmaps that will be
installed into $prefix/share/projectname/pixmaps, with $prefix being
set at configure time. Classical situation for many applications. How
can I make my program find that files?
I'm using Waf to configure/build/install my application, and I can
have created a config.h file with those paths defined, but I don't
know how to access them within my .vala files.
I saw some projects (Valaide for example) using a "Config" namespace
or class, but I could not understand how it works.
I'd be glad if someone could explain me which direction I've to go to
solve this problem.

Thank you.

Federico Pelloni