GLFW Input.

[PJB3005]

Purpose of this PR

Implements input on GLFW. Keyboard input and mouse input works. Gamepad/joystick is not.

I had to fix GLFW window instancing too to actually test this, so if these changes are out of scope I can move them to a separate PR.

There's still a lot to do here but this is already a pretty big PR I would say.

Testing status

I have tested this with the wonderful world of Console.WriteLine and manual main loops.

[varon]

Just deferring this until I've checked over the others as it's quite large!

[varon]

Looks good so far. Only significant change is removing our key enum and just using GLFW directly.

Opinions?

[varon]

Going back and forth on how best to avoid the mismatch issue between GLFW keys and OpenTK.Input.Keys:

Current plan is to update our Key/Mouse/whatever enums to match the GLFW values directly. We use those inside GLFW directly (instead of having a second GLFW key enum and trying to map between them).

This way we get all of the benefits of 1:1 mapping without the hard dependency on GLFW on other platforms.

[varon]

@Vassalware / @jvbsl - Would really appreciate a review on this if you guys can!

[jvbsl]

Except for KeyboardState I found nothing major and looks good so far. I did not test it though

[jvbsl]

I think UnicodeString or something like that would be better. Just naming it String seems wrong to me because System.String is a type

[PJB3005]

I'm open to a better name (AsString maybe?), but UnicodeString or something is kind of redundant since strings are always Unicode.

[varon]

Great work @PJB3005. This is super thorough and well written.

Only required change is the unsafe on the public API. The rest are all nice-to-haves.

[varon]

Kickass work and thanks again, @PJB3005 .

[varon]

Thanks to @jvbsl for the help on the review as well!