But having tried the library, it actually works quite beautifully and is easy to work with. I think it's only because it would cost a sh*t load of money to develop a new gaming engine or to adapt one to Metal rendering. Making all this for such a small market isn't lucrative at all.
I've been very impressed by the amplified performance Metal gives on eg. iPad hardware at the WWDC tech' demos of it.
It's only going to get better. Metal is a young API.
iPhone and iPad as mobile devices have leading edge gpu performance. And that's Metal. That's A12z. With even more impressive cpus on the way...
That augurs well for any Mac ARM transition. We're only a year away from 'Mac' joining the 'party.'
Azrael.