feat: ipd label

src/backend/input.rs

@@ -34,6 +34,7 @@ pub enum TrackedDeviceRole {
 
 pub struct InputState {
     pub hmd: Affine3A,
+    pub ipd: f32,
     pub pointers: [Pointer; 2],
     pub devices: Vec<TrackedDevice>,
 }
@@ -42,6 +43,7 @@ impl InputState {
     pub fn new() -> Self {
         Self {
             hmd: Affine3A::IDENTITY,
+            ipd: 0.0,
             pointers: [Pointer::new(0), Pointer::new(1)],
             devices: Vec::new(),
         }

src/backend/openvr/mod.rs

@@ -93,6 +93,14 @@ pub fn openvr_run(running: Arc<AtomicBool>) -> Result<(), BackendError> {
         AppState::from_graphics(graphics)?
     };
 
+    if let Ok(ipd) = system_mgr.get_tracked_device_property::<f32>(
+        TrackedDeviceIndex::HMD,
+        ETrackedDeviceProperty::Prop_UserIpdMeters_Float,
+    ) {
+        state.input_state.ipd = (ipd * 10000.0).round() * 0.1;
+        log::info!("IPD: {:.1} mm", state.input_state.ipd);
+    }
+
     let _ = install_manifest(&mut app_mgr);
 
     let mut overlays = OverlayContainer::<OpenVrOverlayData>::new(&mut state)?;
@@ -162,6 +170,18 @@ pub fn openvr_run(running: Arc<AtomicBool>) -> Result<(), BackendError> {
                 | EVREventType::VREvent_SceneApplicationChanged => {
                     playspace.playspace_changed(&mut compositor_mgr, &mut chaperone_mgr);
                 }
+                EVREventType::VREvent_IpdChanged => {
+                    if let Ok(ipd) = system_mgr.get_tracked_device_property::<f32>(
+                        TrackedDeviceIndex::HMD,
+                        ETrackedDeviceProperty::Prop_UserIpdMeters_Float,
+                    ) {
+                        let ipd = (ipd * 10000.0).round() * 0.1;
+                        if (ipd - state.input_state.ipd).abs() > 0.05 {
+                            log::info!("IPD: {:.1} mm -> {:.1} mm", state.input_state.ipd, ipd);
+                        }
+                        state.input_state.ipd = ipd;
+                    }
+                }
                 _ => {}
             }
         }

src/backend/openxr/helpers.rs

@@ -109,10 +109,12 @@ pub(super) unsafe fn create_overlay_session(
     }
 }
 
-pub(super) fn hmd_pose_from_views(views: &[xr::View]) -> Affine3A {
+pub(super) fn hmd_pose_from_views(views: &[xr::View]) -> (Affine3A, f32) {
+    let ipd;
     let pos = {
         let pos0: Vec3 = unsafe { std::mem::transmute(views[0].pose.position) };
         let pos1: Vec3 = unsafe { std::mem::transmute(views[1].pose.position) };
+        ipd = (pos0.distance(pos1) * 1000.0).round() * 0.1;
         (pos0 + pos1) * 0.5
     };
     let rot = {
@@ -121,7 +123,7 @@ pub(super) fn hmd_pose_from_views(views: &[xr::View]) -> Affine3A {
         quat_lerp(rot0, rot1, 0.5)
     };
 
-    Affine3A::from_rotation_translation(rot, pos)
+    (Affine3A::from_rotation_translation(rot, pos), ipd)
 }
 
 fn quat_lerp(a: Quat, mut b: Quat, t: f32) -> Quat {

src/backend/openxr/mod.rs

@@ -220,7 +220,8 @@ pub fn openxr_run(running: Arc<AtomicBool>) -> Result<(), BackendError> {
             &xr_state.stage,
         )?;
 
-        app_state.input_state.hmd = helpers::hmd_pose_from_views(&views);
+        (app_state.input_state.hmd, app_state.input_state.ipd) =
+            helpers::hmd_pose_from_views(&views);
 
         overlays
             .iter_mut()