efi user interface

[David Chambers]

Hi, I am in the process of trying to write a user interface to my home
made efi system and am wondering if anyone knows of an easy to use set
of graphing routines for C.
I would like to be able to draw 2D and 3D graphs and then have the user
interact with the graph to change the injection times etc.
Any info on free software or cheap would be much appreciated.
David Chambers