C++/Java code embedding?

[Ginto8]

I was wondering if it's possible to write some C++ code for the robot, and then interface with it through Java. I'd like to know because it seems to me that WPILibJ's NIVision class is pitifully lacking (no edge detection, no convex hull, etc.) and I'd like to be able to use some of its functionality in custom code. Even if interacting with NIVision through the C++ code would be impractical or impossible, it would be equally good if I could write my own custom algorithms that would be either extremely clunky to write in Java (2 words: no pointers), or would be too slow running in a VM. I know NIVision uses JNA to bind the IMAQ functions; would it be possible to use JNA to bind my own functions as well? If so, how?