1 files changed, 6 insertions, 11 deletions
diff --git a/components/script/dom/xrreferencespace.rs b/components/script/dom/xrreferencespace.rs
index c23ea93fd1d..9130c5ae21f 100644
--- a/components/script/dom/xrreferencespace.rs
+++ b/components/script/dom/xrreferencespace.rs
@@ -13,7 +13,7 @@ use crate::dom::xrsession::XRSession;
 use crate::dom::xrspace::XRSpace;
 use crate::dom::xrstationaryreferencespace::XRStationaryReferenceSpace;
 use dom_struct::dom_struct;
-use euclid::Transform3D;
+use euclid::RigidTransform3D;
 use webvr_traits::WebVRFrameData;
 
 #[dom_struct]
@@ -55,30 +55,25 @@ impl XRReferenceSpaceMethods for XRReferenceSpace {
 
 impl XRReferenceSpace {
     /// Gets viewer pose represented by this space
-    pub fn get_viewer_pose(&self, base_pose: &WebVRFrameData) -> Transform3D<f64> {
+    pub fn get_viewer_pose(&self, base_pose: &WebVRFrameData) -> RigidTransform3D<f64> {
         let pose = self.get_pose(base_pose);
 
         // This may change, see https://github.com/immersive-web/webxr/issues/567
-        let offset = self.transform.get().matrix();
-        // XXXManishearth we can directly compute the inverse from the transform parameters
-        // (and perhaps cache it)
-        // XXXManishearth we can also optimize for the unset/identity offset case
-        let inverse = offset
-            .inverse()
-            .expect("rigid transforms are always invertible");
+        let offset = self.transform.get().transform();
+        let inverse = offset.inverse();
         inverse.pre_mul(&pose)
     }
 
     /// Gets pose represented by this space
     ///
     /// Does not apply originOffset, use get_viewer_pose instead if you need it
-    pub fn get_pose(&self, base_pose: &WebVRFrameData) -> Transform3D<f64> {
+    pub fn get_pose(&self, base_pose: &WebVRFrameData) -> RigidTransform3D<f64> {
         if let Some(stationary) = self.downcast::<XRStationaryReferenceSpace>() {
             stationary.get_pose(base_pose)
         } else {
             // non-subclassed XRReferenceSpaces exist, obtained via the "identity"
             // type. The pose does not depend on the base pose.
-            Transform3D::identity()
+            RigidTransform3D::identity()
         }
     }
 }