1 files changed, 35 insertions, 16 deletions

diff --git a/components/script/dom/xrspace.rs b/components/script/dom/xrspace.rs
index 60589be4054..8948ac03c8e 100644
--- a/components/script/dom/xrspace.rs
+++ b/components/script/dom/xrspace.rs
@@ -11,13 +11,14 @@ use crate::dom::globalscope::GlobalScope;
 use crate::dom::xrreferencespace::XRReferenceSpace;
 use crate::dom::xrsession::XRSession;
 use dom_struct::dom_struct;
-use euclid::RigidTransform3D;
+use euclid::{RigidTransform3D, Rotation3D, Vector3D};
 use webvr_traits::WebVRFrameData;
 
 #[dom_struct]
 pub struct XRSpace {
     eventtarget: EventTarget,
     session: Dom<XRSession>,
+    is_viewerspace: bool,
 }
 
 impl XRSpace {
@@ -25,13 +26,21 @@ impl XRSpace {
         XRSpace {
             eventtarget: EventTarget::new_inherited(),
             session: Dom::from_ref(session),
+            is_viewerspace: false,
         }
     }
 
-    #[allow(unused)]
-    pub fn new(global: &GlobalScope, session: &XRSession) -> DomRoot<XRSpace> {
+    fn new_viewerspace_inner(session: &XRSession) -> XRSpace {
+        XRSpace {
+            eventtarget: EventTarget::new_inherited(),
+            session: Dom::from_ref(session),
+            is_viewerspace: true,
+        }
+    }
+
+    pub fn new_viewerspace(global: &GlobalScope, session: &XRSession) -> DomRoot<XRSpace> {
         reflect_dom_object(
-            Box::new(XRSpace::new_inherited(session)),
+            Box::new(XRSpace::new_viewerspace_inner(session)),
             global,
             XRSpaceBinding::Wrap,
         )
@@ -39,25 +48,35 @@ impl XRSpace {
 }
 
 impl XRSpace {
-    /// Gets viewer pose represented by this space
-    #[allow(unused)]
-    pub fn get_viewer_pose(&self, base_pose: &WebVRFrameData) -> RigidTransform3D<f64> {
-        if let Some(reference) = self.downcast::<XRReferenceSpace>() {
-            reference.get_viewer_pose(base_pose)
-        } else {
-            unreachable!()
-        }
-    }
-
     /// Gets pose represented by this space
     ///
-    /// Does not apply originOffset, use get_viewer_pose instead if you need it
-    #[allow(unused)]
+    /// The reference origin used is common between all
+    /// get_pose calls for spaces from the same device, so this can be used to compare
+    /// with other spaces
     pub fn get_pose(&self, base_pose: &WebVRFrameData) -> RigidTransform3D<f64> {
         if let Some(reference) = self.downcast::<XRReferenceSpace>() {
             reference.get_pose(base_pose)
+        } else if self.is_viewerspace {
+            XRSpace::viewer_pose_from_frame_data(base_pose)
         } else {
             unreachable!()
         }
     }
+
+    pub fn viewer_pose_from_frame_data(data: &WebVRFrameData) -> RigidTransform3D<f64> {
+        let pos = data.pose.position.unwrap_or([0., 0., 0.]);
+        let translation = Vector3D::new(pos[0] as f64, pos[1] as f64, pos[2] as f64);
+        let orient = data.pose.orientation.unwrap_or([0., 0., 0., 0.]);
+        let rotation = Rotation3D::quaternion(
+            orient[0] as f64,
+            orient[1] as f64,
+            orient[2] as f64,
+            orient[3] as f64,
+        );
+        RigidTransform3D::new(rotation, translation)
+    }
+
+    pub fn session(&self) -> &XRSession {
+        &self.session
+    }
 }