solving electrostatic field from API

Hello,
Could you please recommend which are the best ways to
- build some simple geometry (constructed from simple primitives like cylinder, box, etc).
- mesh it
- solve the electrostatic field with potentials defined on some solids (+mesh refinement)
fully from a (preferably C++) code? All the examples and tutorials which I find use geometry input from different files, or use a GUI to do this, etc. I want to construct some electrode configuration from within my code, calculate the electrostatic field, and then tune my geometry to reach some goal. Using a GUI is nice but cumbersome.
Thanks
Daniel

Did you have a look at the fenics-project : fenicsproject.org/

or SfePy : sfepy.org/doc-devel/index.html#

both are in Python