webxr: Update XRView to latest spec (#33145)

* Add recommendedViewportScale and requestViewportScale

Signed-off-by: Daniel Adams <msub2official@gmail.com>

* Remove currently unused internal slots

Signed-off-by: Daniel Adams <msub2official@gmail.com>

---------

Signed-off-by: Daniel Adams <msub2official@gmail.com>

components/script/dom/webidls/XRView.webidl

@@ -14,7 +14,10 @@ enum XREye {
 interface XRView {
   readonly attribute XREye eye;
   readonly attribute Float32Array projectionMatrix;
-  readonly attribute XRRigidTransform transform;
+  [SameObject] readonly attribute XRRigidTransform transform;
+  readonly attribute double? recommendedViewportScale;
+
+  undefined requestViewportScale(double? scale);
 
   // AR Module
   readonly attribute boolean isFirstPersonObserver;

components/script/dom/xrview.rs

@@ -2,6 +2,8 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
 
+use std::cell::Cell;
+
 use dom_struct::dom_struct;
 use euclid::RigidTransform3D;
 use js::typedarray::{Float32, Float32Array};
@@ -9,6 +11,7 @@ use webxr_api::{ApiSpace, View};
 
 use super::bindings::buffer_source::HeapBufferSource;
 use crate::dom::bindings::codegen::Bindings::XRViewBinding::{XREye, XRViewMethods};
+use crate::dom::bindings::num::Finite;
 use crate::dom::bindings::reflector::{reflect_dom_object, Reflector};
 use crate::dom::bindings::root::{Dom, DomRoot};
 use crate::dom::globalscope::GlobalScope;
@@ -28,6 +31,7 @@ pub struct XRView {
     #[no_trace]
     view: View<ApiSpace>,
     transform: Dom<XRRigidTransform>,
+    requested_viewport_scale: Cell<f64>,
 }
 
 impl XRView {
@@ -46,6 +50,7 @@ impl XRView {
             proj: HeapBufferSource::default(),
             view,
             transform: Dom::from_ref(transform),
+            requested_viewport_scale: Cell::new(1.0),
         }
     }
 
@@ -107,6 +112,22 @@ impl XRViewMethods for XRView {
         DomRoot::from_ref(&self.transform)
     }
 
+    /// <https://www.w3.org/TR/webxr/#dom-xrview-recommendedviewportscale>
+    fn GetRecommendedViewportScale(&self) -> Option<Finite<f64>> {
+        // Just return 1.0 since we currently will always use full-sized viewports
+        Finite::new(1.0)
+    }
+
+    /// <https://www.w3.org/TR/webxr/#dom-xrview-requestviewportscale>
+    fn RequestViewportScale(&self, scale: Option<Finite<f64>>) {
+        if let Some(scale) = scale {
+            if *scale > 0.0 {
+                let clamped_scale = scale.clamp(0.0, 1.0);
+                self.requested_viewport_scale.set(clamped_scale);
+            }
+        }
+    }
+
     /// <https://www.w3.org/TR/webxr-ar-module-1/#dom-xrview-isfirstpersonobserver>
     fn IsFirstPersonObserver(&self) -> bool {
         // Servo is not currently supported anywhere that supports this, so return false

components/script/dom/xrwebgllayer.rs

@@ -316,7 +316,7 @@ impl XRWebGLLayerMethods for XRWebGLLayer {
         let index = view.viewport_index();
 
         let viewport = self.session().with_session(|s| {
-            // Inline sssions
+            // Inline sessions
             if s.viewports().is_empty() {
                 Rect::from_size(self.size().to_i32())
             } else {
@@ -324,6 +324,11 @@ impl XRWebGLLayerMethods for XRWebGLLayer {
             }
         });
 
+        // NOTE: According to spec, viewport sizes should be recalculated here if the
+        // requested viewport scale has changed. However, existing browser implementations
+        // don't seem to do this for stereoscopic immersive sessions.
+        // Revisit if Servo gets support for handheld AR/VR via ARCore/ARKit
+
         Some(XRViewport::new(&self.global(), viewport))
     }
 }

tests/wpt/meta-legacy-layout/webxr/idlharness.https.window.js.ini

@@ -317,12 +317,6 @@
   [XRSession interface: calling cancelAnimationFrame(unsigned long) on xrSession with too few arguments must throw TypeError]
     expected: FAIL
 
-  [XRView interface: attribute recommendedViewportScale]
-    expected: FAIL
-
-  [XRView interface: operation requestViewportScale(double?)]
-    expected: FAIL
-
   [XRPose interface: attribute linearVelocity]
     expected: FAIL
 

tests/wpt/meta-legacy-layout/webxr/xr_viewport_scale.https.html.ini

@@ -1,85 +1,24 @@
 [xr_viewport_scale.https.html]
-  expected: ERROR
-  [requestViewportScale valid viewport for inline session - webgl]
-    expected: TIMEOUT
-
-  [recommendedViewportScale for immersive-vr session - webgl2]
-    expected: NOTRUN
-
   [requestViewportScale applied next frame for immersive-vr session - webgl]
-    expected: NOTRUN
+    expected: PRECONDITION_FAILED
-
-  [requestViewportScale valid viewport w/ very small scale for inline session - webgl]
-    expected: NOTRUN
 
   [requestViewportScale same frame for inline session - webgl]
-    expected: NOTRUN
+    expected: PRECONDITION_FAILED
 
   [requestViewportScale same frame for immersive-vr session - webgl]
-    expected: NOTRUN
+    expected: PRECONDITION_FAILED
-
-  [requestViewportScale valid viewport w/ null scale for immersive-vr session - webgl]
-    expected: NOTRUN
-
-  [requestViewportScale valid viewport w/ undefined scale for inline session - webgl]
-    expected: NOTRUN
 
   [requestViewportScale applied next frame for immersive-vr session - webgl2]
-    expected: NOTRUN
+    expected: PRECONDITION_FAILED
-
-  [requestViewportScale valid viewport for immersive-vr session - webgl]
-    expected: NOTRUN
-
-  [requestViewportScale valid viewport w/ very small scale for immersive-vr session - webgl2]
-    expected: NOTRUN
 
   [requestViewportScale applied next frame for inline session - webgl]
-    expected: NOTRUN
+    expected: PRECONDITION_FAILED
-
-  [recommendedViewportScale for inline session - webgl2]
-    expected: NOTRUN
-
-  [requestViewportScale valid viewport w/ very small scale for inline session - webgl2]
-    expected: NOTRUN
 
   [requestViewportScale same frame for immersive-vr session - webgl2]
-    expected: NOTRUN
+    expected: PRECONDITION_FAILED
-
-  [requestViewportScale valid viewport w/ null scale for inline session - webgl2]
-    expected: NOTRUN
-
-  [recommendedViewportScale for inline session - webgl]
-    expected: NOTRUN
-
-  [requestViewportScale valid viewport for immersive-vr session - webgl2]
-    expected: NOTRUN
-
-  [requestViewportScale valid viewport w/ undefined scale for immersive-vr session - webgl2]
-    expected: NOTRUN
-
-  [requestViewportScale valid viewport w/ undefined scale for immersive-vr session - webgl]
-    expected: NOTRUN
 
   [requestViewportScale same frame for inline session - webgl2]
-    expected: NOTRUN
+    expected: PRECONDITION_FAILED
 
   [requestViewportScale applied next frame for inline session - webgl2]
-    expected: NOTRUN
+    expected: PRECONDITION_FAILED
-
-  [recommendedViewportScale for immersive-vr session - webgl]
-    expected: NOTRUN
-
-  [requestViewportScale valid viewport for inline session - webgl2]
-    expected: NOTRUN
-
-  [requestViewportScale valid viewport w/ null scale for inline session - webgl]
-    expected: NOTRUN
-
-  [requestViewportScale valid viewport w/ null scale for immersive-vr session - webgl2]
-    expected: NOTRUN
-
-  [requestViewportScale valid viewport w/ very small scale for immersive-vr session - webgl]
-    expected: NOTRUN
-
-  [requestViewportScale valid viewport w/ undefined scale for inline session - webgl2]
-    expected: NOTRUN

tests/wpt/meta/webxr/idlharness.https.window.js.ini

@@ -260,12 +260,6 @@
   [XRSession interface: calling cancelAnimationFrame(unsigned long) on xrSession with too few arguments must throw TypeError]
     expected: FAIL
 
-  [XRView interface: attribute recommendedViewportScale]
-    expected: FAIL
-
-  [XRView interface: operation requestViewportScale(double?)]
-    expected: FAIL
-
   [XRPose interface: attribute linearVelocity]
     expected: FAIL
 

tests/wpt/meta/webxr/xr_viewport_scale.https.html.ini

@@ -1,127 +1,24 @@
 [xr_viewport_scale.https.html]
-  expected: ERROR
-  [requestViewportScale valid viewport for inline session]
-    expected: TIMEOUT
-
-  [requestViewportScale valid viewport w/ null scale for inline session]
-    expected: NOTRUN
-
-  [recommendedViewportScale for immersive-vr session]
-    expected: NOTRUN
-
-  [requestViewportScale applied next frame for inline session]
-    expected: NOTRUN
-
-  [requestViewportScale valid viewport w/ very small scale for inline session]
-    expected: NOTRUN
-
-  [requestViewportScale valid viewport w/ undefined scale for immersive-vr session]
-    expected: NOTRUN
-
-  [requestViewportScale valid viewport for immersive-vr session]
-    expected: NOTRUN
-
-  [requestViewportScale same frame for inline session]
-    expected: NOTRUN
-
-  [recommendedViewportScale for inline session]
-    expected: NOTRUN
-
-  [requestViewportScale same frame for immersive-vr session]
-    expected: NOTRUN
-
-  [requestViewportScale valid viewport w/ very small scale for immersive-vr session]
-    expected: NOTRUN
-
-  [requestViewportScale valid viewport w/ null scale for immersive-vr session]
-    expected: NOTRUN
-
-  [requestViewportScale valid viewport w/ undefined scale for inline session]
-    expected: NOTRUN
-
-  [requestViewportScale applied next frame for immersive-vr session]
-    expected: NOTRUN
-
-  [requestViewportScale valid viewport for inline session - webgl]
-    expected: TIMEOUT
-
-  [recommendedViewportScale for immersive-vr session - webgl2]
-    expected: NOTRUN
-
   [requestViewportScale applied next frame for immersive-vr session - webgl]
-    expected: NOTRUN
+    expected: PRECONDITION_FAILED
-
-  [requestViewportScale valid viewport w/ very small scale for inline session - webgl]
-    expected: NOTRUN
 
   [requestViewportScale same frame for inline session - webgl]
-    expected: NOTRUN
+    expected: PRECONDITION_FAILED
 
   [requestViewportScale same frame for immersive-vr session - webgl]
-    expected: NOTRUN
+    expected: PRECONDITION_FAILED
-
-  [requestViewportScale valid viewport w/ null scale for immersive-vr session - webgl]
-    expected: NOTRUN
-
-  [requestViewportScale valid viewport w/ undefined scale for inline session - webgl]
-    expected: NOTRUN
 
   [requestViewportScale applied next frame for immersive-vr session - webgl2]
-    expected: NOTRUN
+    expected: PRECONDITION_FAILED
-
-  [requestViewportScale valid viewport for immersive-vr session - webgl]
-    expected: NOTRUN
-
-  [requestViewportScale valid viewport w/ very small scale for immersive-vr session - webgl2]
-    expected: NOTRUN
 
   [requestViewportScale applied next frame for inline session - webgl]
-    expected: NOTRUN
+    expected: PRECONDITION_FAILED
-
-  [recommendedViewportScale for inline session - webgl2]
-    expected: NOTRUN
-
-  [requestViewportScale valid viewport w/ very small scale for inline session - webgl2]
-    expected: NOTRUN
 
   [requestViewportScale same frame for immersive-vr session - webgl2]
-    expected: NOTRUN
+    expected: PRECONDITION_FAILED
-
-  [requestViewportScale valid viewport w/ null scale for inline session - webgl2]
-    expected: NOTRUN
-
-  [recommendedViewportScale for inline session - webgl]
-    expected: NOTRUN
-
-  [requestViewportScale valid viewport for immersive-vr session - webgl2]
-    expected: NOTRUN
-
-  [requestViewportScale valid viewport w/ undefined scale for immersive-vr session - webgl2]
-    expected: NOTRUN
-
-  [requestViewportScale valid viewport w/ undefined scale for immersive-vr session - webgl]
-    expected: NOTRUN
 
   [requestViewportScale same frame for inline session - webgl2]
-    expected: NOTRUN
+    expected: PRECONDITION_FAILED
 
   [requestViewportScale applied next frame for inline session - webgl2]
-    expected: NOTRUN
+    expected: PRECONDITION_FAILED
-
-  [recommendedViewportScale for immersive-vr session - webgl]
-    expected: NOTRUN
-
-  [requestViewportScale valid viewport for inline session - webgl2]
-    expected: NOTRUN
-
-  [requestViewportScale valid viewport w/ null scale for inline session - webgl]
-    expected: NOTRUN
-
-  [requestViewportScale valid viewport w/ null scale for immersive-vr session - webgl2]
-    expected: NOTRUN
-
-  [requestViewportScale valid viewport w/ very small scale for immersive-vr session - webgl]
-    expected: NOTRUN
-
-  [requestViewportScale valid viewport w/ undefined scale for inline session - webgl2]
-    expected: NOTRUN