Drawing Cogwheels and Combinatoric diagrams

[Andrew James]

Gentlemen,
I'm looking for a graphing or drawing python package that will allow me 
to draw complex geometric shapes. I need to be able to create shapes 
like cogwheels and Venn diagrams:

http://encyclopedia.thefreedictionary.com/Venn

The library must support alpha blending and the ability to return x,y 
co-ordinates for a shape, as I want to draw an imagemap on top of parts 
of the shape.

Can PIL do this, or do I need to go the way of GnuPlot or Gri? Can 
anyone give me an example of a complex shape drawn like this?

Many thanks,
Andrew