Merge branch 'wivrn-solarxr' into 'main'

fossvr/wivrn: Add SlimeVR section

See merge request lvra/lvra.gitlab.io!83

content/docs/fossvr/wivrn/_index.md

@@ -68,6 +68,44 @@ Manual steps:
   adb shell am start -a android.intent.action.VIEW -d "wivrn+tcp://127.0.0.1" org.meumeu.wivrn
   ```
 
+## WiVRn + SlimeVR trackers
+
+To use SlimeVR trackers through WiVRn, you currently must use a [fork](https://github.com/notpeelz/WiVRn) of WiVRn:
+
+### Usage with Envision
+
+To use this fork within Envision, edit these fields in your profile:
+- XR Service Repo: `https://github.com/notpeelz/WiVRn.git`
+- XR Service Branch: `solarxr-patches`
+
+Then save and clean build the profile.
+
+### NixOS setup
+Override the `wivrn` package from nixpkgs with something resembling the following, replacing `[COMMIT HASH HERE]` with the latest commit hash from https://github.com/notpeelz/WiVRn/commits/solarxr-patches and filling in the correct src hash. Do note you may need to adapt this depending on how you install WiVRn:
+```nix
+{ pkgs, lib, ... }:
+
+{
+  services.wivrn = {
+    enable = true;
+    defaultRuntime = true;
+    package = pkgs.wivrn.overrideAttrs (old: rec {
+      version = "[COMMIT HASH HERE]";
+      src = lib.fetchFromGitHub {
+        owner = "notpeelz";
+        repo = "WiVRn";
+        rev = version;
+        # This will throw an error when evaluating and give you the correct hash - put that here
+        hash = "";
+      };
+      cmakeFlags = old.cmakeFlags ++ [
+        (lib.cmakeBool "WIVRN_FEATURE_SOLARXR" true)
+      ];
+    });
+  };
+}
+```
+
 ## WiVRn + Lighthouse driver
 
 This section covers using WiVRn with any Lighthouse-tracked device: Index/Vive controllers, Vive/Tundra trackers, etc.