Because both ImageMagick and libart are buggy, this version uses
a hybrid soltution where all polygons are painted using libart,
and everything else using ImageMagick. Yuck.
libart is available from Ruby/Gnome2
http://taw.pl.eu.org/~taw/earth.mng (800kB) or
http://taw.pl.eu.org/~taw/earth.gif (2MB) show animation of rotating Earth.
Of course equal-area projection is particularly badly suited for that,
but it looks cool anyway ;)
The following things are cached:
* bluemarble
* libart generated polygons
* rivers
