slowly. Slowly. Building up a UI test window for Unity. A way to preview UI without having to launch the game

So many competing approaches to different systems, sharp corners in code (oops, there are 3 variables for the same camera on the same data struct and you didnt set all 3! so. it wont work), and bad documentation have made this hard, but its getting there!

The UI is rendering and taking mouse input. Unfortunately, the runtime input systems are totally disconnected from the editor input, so I have to manually push each input event through. Including converting coordinate spaces because for some reason the editor uses a different coordinate space from the runtime /∆\ (Y is flipped)

Fr tho, Unity is AWFUL like. wow. I wasn't exagerating on the 3 same camera variables thing, and the different coordinate spaces thing is mind-bogglingly poor execution.