I have also been working for one of our projects to update MT4J to be able to use OpenGL 4.0+ and Processing 2.0.
I have made a working version that uses GL2 code instead of the original GL context(I can get the graphics to render, with the exceptions outlined below).
Some of the most important issues I have are the following:
-> text and texture renderings are not working at all(the renderers need to be probably rewritten)
-> there is an issue when enabling and disabling clipping, this gives an exception that I am not using a GL2 implementation..(which I am); the clipping code has been commented out
Further the mouse and keyboard processing 1.0 sketches are invalid. I have corrected the mouse sketch, but haven’t bothered with the keyboard, as the previous problems are of more importance.
If anyone wants to help, please let me know and I can share the code.