JOGL with Rift - some progress but strange clipping

off topic ,but Vulkan sounds interesting! and good to see Sven is already on the case :)

anyway I started some work again on my VR experiments.  I managed to get something working with JOGL now :) but I'm seeing a strange clipping issue.  It is evident running the program without a DK2 as the blue strip at the top of the display.  I've tried to simplify my code as much as possible, and it is still Opengl 2.1 since I wanted to try and get something basic working first so that I can learn as I go along.

Any tips would be much appreciated.

RiftClient0440NoMatirx

https://github.com/WhiteHexagon/example-jovr-jogl-rift

Thanks
Peter