Merge pull request #37 from ForTehLose/optionalHands

only add hand resource if we support the ext

src/lib.rs

@@ -20,6 +20,7 @@ use input::XrInput;
 use openxr as xr;
 use resources::*;
 use xr_input::controllers::XrControllerType;
+use xr_input::hand::HandInputSource;
 use xr_input::handtracking::HandTrackingTracker;
 use xr_input::OpenXrInput;
 
@@ -144,8 +145,14 @@ impl Plugin for OpenXrPlugin {
                 .insert_resource(input.clone())
                 .insert_resource(views.clone())
                 .insert_resource(frame_state.clone())
-                .insert_resource(action_sets.clone())
+                .insert_resource(action_sets.clone());
-                .insert_resource(HandTrackingTracker::new(&session).unwrap());
+            let hands = xr_instance.exts().ext_hand_tracking.is_some();
+            if hands {
+                app.insert_resource(HandTrackingTracker::new(&session).unwrap());
+                app.insert_resource(HandInputSource::OpenXr);
+            } else {
+                app.insert_resource(HandInputSource::Emulated);
+            }
 
             let (left, right) = swapchain.get_render_views();
             let left = ManualTextureView {

src/xr_input/hand.rs

@@ -30,8 +30,8 @@ impl Plugin for OpenXrHandInput {
         app.add_systems(Update, update_hand_skeletons)
             .add_systems(PreUpdate, update_hand_states)
             .add_systems(Startup, spawn_hand_entities)
-            .insert_resource(HandStatesResource::default())
+            .insert_resource(HandStatesResource::default());
-            .insert_resource(HandInputSource::default());
+        // .insert_resource(HandInputSource::default());
     }
 }
 
@@ -1068,7 +1068,7 @@ pub fn update_hand_skeletons(
         Without<OpenXRTrackingRoot>,
     )>,
     input_source: Option<Res<HandInputSource>>,
-    hand_tracking: Res<HandTrackingTracker>,
+    hand_tracking: Option<Res<HandTrackingTracker>>,
     xr_input: Res<XrInput>,
     xr_frame_state: Res<XrFrameState>,
 ) {
@@ -1104,13 +1104,15 @@ pub fn update_hand_skeletons(
                     None => info!("hand states resource not initialized yet"),
                 }
             }
-            HandInputSource::OpenXr => {
+            HandInputSource::OpenXr => match hand_tracking {
-                let hand_ref = hand_tracking.get_ref(&xr_input, &xr_frame_state);
+                Some(tracking) => {
+                    let hand_ref = tracking.get_ref(&xr_input, &xr_frame_state);
                     let (root_transform, _) = tracking_root_query.get_single().unwrap();
                     let left_data = hand_ref.get_left_poses();
                     let right_data = hand_ref.get_right_poses();
 
-                for (entity, mut transform, bone, hand, radius, _) in hand_bone_query.iter_mut() {
+                    for (entity, mut transform, bone, hand, radius, _) in hand_bone_query.iter_mut()
+                    {
                         let bone_data = match (hand, left_data, right_data) {
                             (Hand::Left, Some(data), _) => data[bone.get_index_from_bone()],
                             (Hand::Right, _, Some(data)) => data[bone.get_index_from_bone()],
@@ -1133,6 +1135,8 @@ pub fn update_hand_skeletons(
                             )
                     }
                 }
+                None => {}
+            },
         },
         None => {
             info!("hand input source not initialized");