Marco, It looks to me that
 

Marco,

It looks to me that you are re-inventing the wheel. The sampledPlane class should already provide most of what you want (I think).

Marco, I pointed out the sa
 

Marco,

I pointed out the sampledPlane class, but it doesn't look like you bothered to read the documents at all. Please read the doxygen docs before posting!

The 'area', the 'average', the 'integrate', the 'project' and the 'sample' methods should cover most of what you want. If not, you'll have to program something yourself. Look at how these methods are implemented for ideas about how to do something similar yourself.