Well it allows to display a picture onto a vr device by
1) duplicating the picture (for each eye)
2) applying the inverse geometrical deformation to compensate for oculus/vr lenses deformation
See this for details; note that the one i provided you with is GLES compliant (and is found in the comments of the url below)
Thanks for the info and link. Seems pretty neat. Also a bit niche, not sure how many people would benefit from it. I have actually been thinking of adding true VR support (with head tracking) at least for the android version (that can be used with goggle cardboard). Haven't got around to it yet though, but it's on my list of things to look into.
