Cross-platform input for Valve Index

bool isOpenVrSystemReady()
    {
	try
	{
		return OVR.OpenVR.OpenVR.System != null;
	} catch(DllNotFoundException e)
	{
		return false;
	}
    }

this is to get the index of the controller you want to get input from, which can change at runtime (right left switching), although I'm not sure if it works if the controllers aren't on when the game starts. I passed "OVR.OpenVR.ETrackedControllerRole.LeftHand" as the proper role to get the left controller inputs. I'm sure you can imagine what to pass for the right hand, as it's an enum, so replace the LeftHand name with RightHand.

uint getDeviceIndex(OVR.OpenVR.ETrackedControllerRole role)
    {
        //get device index of controller, may change during runtime as they turn on/off
        if (isOpenVrSystemReady())
            return OVR.OpenVR.OpenVR.System.GetTrackedDeviceIndexForControllerRole(role);
        else return 1000;
    }

this is to get the name of the controller you are looking at, which will let you test against the string "knuckles" to tell if you need to use special input exceptions (I know, even this code refers to them as knuckles and not indexes). Given you may call this so much, I also would opt to store the pre-created err somewhere else and not create a new one each time you call this, but I put it like this for easiest copy-pasting right now.

string getControllerName(OVR.OpenVR.ETrackedControllerRole controllerRole)
    {
        OVR.OpenVR.ETrackedPropertyError err = new OVR.OpenVR.ETrackedPropertyError();
        //get name of controller
        if (isOpenVrSystemReady())
        {
            OVR.OpenVR.OpenVR.System.GetStringTrackedDeviceProperty(getDeviceIndex(controllerRole), OVR.OpenVR.ETrackedDeviceProperty.Prop_ControllerType_String, controllerTitle, (uint)System.Runtime.InteropServices.Marshal.SizeOf(controllerTitle), ref err);
            return controllerTitle.ToString();
        }
        else return "";
    }

to get the input, you will need to just make a "new OVR.OpenVR.VRControllerState_t()" and pass it to this after storing it (you don't need to make a new one each time you call this) which will give you the state of the controller.

bool updateControllerState(OVR.OpenVR.ETrackedControllerRole controllerRole, ref OVR.OpenVR.VRControllerState_t state)
    {
        //update the state of the controller
        if (isOpenVrSystemReady())
            return OVR.OpenVR.OpenVR.System.GetControllerState(getDeviceIndex(controllerRole), ref state, (uint)System.Runtime.InteropServices.Marshal.SizeOf(state)); //get the controller state which is weird structure
        else return false;
    }

And after passing it to the last function, the state object will have the current state of the controller, which will mean you need to get the correct axis, which will be something like this line:

storedState.rAxis0.x //or .rAxis.y

(You may be able to get the fingers axis inputs through the other r.Axis1 through 4, but I give no gaurantees)

However some things of note, you will want to make sure to have a small dead zone around about .1 in size, because if they just touch their thumbstick (resting their finger on it even) it counts as an input on one of the axis, so to avoid weird drifting I just ended up testing if it was bigger than .1 then used the value otherwise. 

So an example usage block we had was this, just to give people an idea.

if (isOpenVrSystemReady() && getControllerName(OVR.OpenVR.ETrackedControllerRole.LeftHand) == "knuckles")
		{//"vive_controller" is the name of vive wands
			updateControllerState(OVR.OpenVR.ETrackedControllerRole.LeftHand, ref leftState);
			if (Mathf.Abs(leftState.rAxis0.x) > 0.1f || Mathf.Abs(leftState.rAxis0.y) > 0.1f) //dead zone because touching thumbstick makes it register not 0
			{
				primaryAxis.x = leftState.rAxis0.x;
				primaryAxis.y = leftState.rAxis0.y; //y is up-down, x is left-right.
			}
		}

Alright, that seems like enough to give people a good idea of how to get index controller inputs, at least not using the new XR management stuff, which I'm not sure if it breaks this. Anyway, I hope this all helps and alleviate the pains of oculus being weird!