I’m an experienced programmer with some specific professional areas of expertise which do not include cross-platform real-time computer 3d graphics. However i want to move towards it, especially to the cross-platform part. I used to know a bit about opengl years ago which means mainly 1.4 stuff and as far as i understand it is getting deprecated know. Does this mean that all the old books on the subject are irrelevant now? Please advise where to start learning now, what books to use, e.t.c.