I know it supports XInput on PC. But is it possible to play old games which only have DirectInput with the controller?
So, I've installed Jade Empire to play it with my Xbox One controller. The game is rather old (and the port is rather terrible) but Steam says it has partial controller support (and who are we to question the word of Gaben?). The controls are actually okay-ish, except the little fact that JE apparently uses DirectInput and because of that it doesn't recognizes triggers as a separate buttons and instead they act like a single button. According to MSDN it's not a bug, it's a feature. Which is sad.
You can read more about the limitations of the Xbox 360 controllers when using DirectInput here. I believe the very same limitations aply to the Xbox One controller as well.