Auto merge of #23159 - Manishearth:rigid-transforms, r=<try>

Update XR code to use rigid transforms and new pose/transform stuff from the spec

This updates our XR code to use euclid's new [RigidTransform3D type](servo/euclid#328), which is more efficent and convenient to work with.

It additionally brings us up to speed with the spec:

 - `XRViewerPose` was made a subclass of `XRPose` (immersive-web/webxr#496)
 - `XRView.viewMatrix` was removed in favor of `XRRigidTransform.inverse.matrix` (immersive-web/webxr#531)
 - `XRRigidTransform.inverse` is an attribute (immersive-web/webxr#560)
 - `XRRigidTransform` now validates positions in its constructor (immersive-web/webxr#568)

Furthermore, it adds support for `XRRigidTransform.matrix`.

While fixing this I also noticed that our view matrix code was incorrect, we calculated view matrices as `pose.to_column_major_array()`, whereas it *should* be `pose.inverse().to_row_major_array()` (since Euclid uses row vectors, whenever the spec says it wants a column major array we should use `.to_row_major_array()` since all web specs implicitly use column vectors). For 3DOF devices poses are mostly rotations anyway, so the effective transpose behaved _like_ an inversion, but was incorrect.

This PR gets rid of `view.viewMatrix` anyway, however I felt like I should mention this discrepancy, since otherwise the replacement of `view.viewMatrix` with `view.transform.inverse.matrix` doesn't make sense

r? @jdm

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components/script/Cargo.toml

@@ -50,7 +50,7 @@ domobject_derive = {path = "../domobject_derive"}
 embedder_traits = {path = "../embedder_traits"}
 encoding_rs = "0.8"
 enum-iterator = "0.2.0"
-euclid = "0.19"
+euclid = "0.19.7"
 fnv = "1.0"
 gleam = "0.6"
 headers-core = "0.0.1"

components/script/dom/bindings/trace.rs

@@ -57,7 +57,8 @@ use devtools_traits::{CSSError, TimelineMarkerType, WorkerId};
 use encoding_rs::{Decoder, Encoding};
 use euclid::Length as EuclidLength;
 use euclid::{
-    Point2D, Rect, Rotation3D, Transform2D, Transform3D, TypedScale, TypedSize2D, Vector2D,
+    Point2D, Rect, RigidTransform3D, Rotation3D, Transform2D, Transform3D, TypedScale, TypedSize2D,
+    Vector2D,
 };
 use html5ever::buffer_queue::BufferQueue;
 use html5ever::{LocalName, Namespace, Prefix, QualName};
@@ -494,7 +495,8 @@ unsafe_no_jsmanaged_fields!(ResourceFetchTiming);
 unsafe_no_jsmanaged_fields!(Timespec);
 unsafe_no_jsmanaged_fields!(HTMLMediaElementFetchContext);
 unsafe_no_jsmanaged_fields!(Rotation3D<f64>, Transform2D<f32>, Transform3D<f64>);
-unsafe_no_jsmanaged_fields!(Point2D<f32>, Vector2D<f32>, Rect<Au>, Rect<f32>);
+unsafe_no_jsmanaged_fields!(Point2D<f32>, Vector2D<f32>, Rect<Au>);
+unsafe_no_jsmanaged_fields!(Rect<f32>, RigidTransform3D<f64>);
 
 unsafe impl<'a> JSTraceable for &'a str {
     #[inline]

components/script/dom/dompointreadonly.rs

@@ -2,7 +2,6 @@
  * 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 crate::dom::bindings::codegen::Bindings::DOMPointBinding::DOMPointInit;
 use crate::dom::bindings::codegen::Bindings::DOMPointReadOnlyBinding::{
     DOMPointReadOnlyMethods, Wrap,
 };
@@ -51,10 +50,6 @@ impl DOMPointReadOnly {
     ) -> Fallible<DomRoot<DOMPointReadOnly>> {
         Ok(DOMPointReadOnly::new(global, x, y, z, w))
     }
-
-    pub fn new_from_init(global: &GlobalScope, p: &DOMPointInit) -> DomRoot<DOMPointReadOnly> {
-        DOMPointReadOnly::new(global, p.x, p.y, p.z, p.w)
-    }
 }
 
 impl DOMPointReadOnlyMethods for DOMPointReadOnly {

components/script/dom/mod.rs

@@ -537,6 +537,7 @@ pub mod xmlserializer;
 pub mod xr;
 pub mod xrframe;
 pub mod xrlayer;
+pub mod xrpose;
 pub mod xrreferencespace;
 pub mod xrrenderstate;
 pub mod xrrigidtransform;

components/script/dom/webidls/XRPose.webidl

@@ -0,0 +1,11 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * 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/. */
+
+// https://immersive-web.github.io/webxr/#xrpose-interface
+
+[SecureContext, Exposed=Window, Pref="dom.webxr.enabled"]
+interface XRPose {
+  readonly attribute XRRigidTransform transform;
+  // readonly attribute boolean emulatedPosition;
+};

components/script/dom/webidls/XRRigidTransform.webidl

@@ -9,6 +9,6 @@
 interface XRRigidTransform {
   readonly attribute DOMPointReadOnly position;
   readonly attribute DOMPointReadOnly orientation;
-  // readonly attribute Float32Array matrix;
-  XRRigidTransform inverse();
+  readonly attribute Float32Array matrix;
+  readonly attribute XRRigidTransform inverse;
 };

components/script/dom/webidls/XRView.webidl

@@ -13,6 +13,5 @@ enum XREye {
 interface XRView {
   readonly attribute XREye eye;
   readonly attribute Float32Array projectionMatrix;
-  readonly attribute Float32Array viewMatrix;
-  // readonly attribute XRRigidTransform transform;
+  readonly attribute XRRigidTransform transform;
 };

components/script/dom/webidls/XRViewerPose.webidl

@@ -5,8 +5,7 @@
 // https://immersive-web.github.io/webxr/#xrviewerpose-interface
 
 [SecureContext, Exposed=Window, Pref="dom.webxr.enabled"]
-interface XRViewerPose {
-  // readonly attribute XRRigidTransform transform;
+interface XRViewerPose : XRPose {
   // readonly attribute FrozenArray<XRView> views;
   // workaround until we have FrozenArray
   // see https://github.com/servo/servo/issues/10427#issuecomment-449593626

components/script/dom/xrframe.rs

@@ -4,13 +4,11 @@
 
 use crate::dom::bindings::codegen::Bindings::XRFrameBinding;
 use crate::dom::bindings::codegen::Bindings::XRFrameBinding::XRFrameMethods;
-use crate::dom::bindings::codegen::Bindings::XRViewBinding::XREye;
 use crate::dom::bindings::reflector::{reflect_dom_object, DomObject, Reflector};
 use crate::dom::bindings::root::{Dom, DomRoot};
 use crate::dom::globalscope::GlobalScope;
 use crate::dom::xrreferencespace::XRReferenceSpace;
 use crate::dom::xrsession::XRSession;
-use crate::dom::xrview::XRView;
 use crate::dom::xrviewerpose::XRViewerPose;
 use dom_struct::dom_struct;
 use webvr_traits::WebVRFrameData;
@@ -54,20 +52,11 @@ impl XRFrameMethods for XRFrame {
     /// https://immersive-web.github.io/webxr/#dom-xrframe-getviewerpose
     fn GetViewerPose(&self, reference: &XRReferenceSpace) -> Option<DomRoot<XRViewerPose>> {
         let pose = reference.get_viewer_pose(&self.data);
-        let left = XRView::new(
+        Some(XRViewerPose::new(
             &self.global(),
             &self.session,
-            XREye::Left,
-            &pose,
+            pose,
             &self.data,
-        );
-        let right = XRView::new(
-            &self.global(),
-            &self.session,
-            XREye::Right,
-            &pose,
-            &self.data,
-        );
-        Some(XRViewerPose::new(&self.global(), &left, &right))
+        ))
     }
 }

components/script/dom/xrpose.rs

@@ -0,0 +1,44 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * 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 crate::dom::bindings::codegen::Bindings::XRPoseBinding;
+use crate::dom::bindings::codegen::Bindings::XRPoseBinding::XRPoseMethods;
+use crate::dom::bindings::reflector::{reflect_dom_object, Reflector};
+use crate::dom::bindings::root::{Dom, DomRoot};
+use crate::dom::globalscope::GlobalScope;
+use crate::dom::xrrigidtransform::XRRigidTransform;
+use dom_struct::dom_struct;
+use euclid::RigidTransform3D;
+
+#[dom_struct]
+pub struct XRPose {
+    reflector_: Reflector,
+    transform: Dom<XRRigidTransform>,
+}
+
+impl XRPose {
+    pub fn new_inherited(transform: &XRRigidTransform) -> XRPose {
+        XRPose {
+            reflector_: Reflector::new(),
+            transform: Dom::from_ref(transform),
+        }
+    }
+
+    #[allow(unused)]
+    pub fn new(global: &GlobalScope, transform: RigidTransform3D<f64>) -> DomRoot<XRPose> {
+        let transform = XRRigidTransform::new(global, transform);
+        reflect_dom_object(
+            Box::new(XRPose::new_inherited(&transform)),
+            global,
+            XRPoseBinding::Wrap,
+        )
+    }
+}
+
+impl XRPoseMethods for XRPose {
+    /// https://immersive-web.github.io/webxr/#dom-xrpose-transform
+    fn Transform(&self) -> DomRoot<XRRigidTransform> {
+        DomRoot::from_ref(&self.transform)
+    }
+}

components/script/dom/xrreferencespace.rs

@@ -7,14 +7,13 @@ use crate::dom::bindings::codegen::Bindings::XRReferenceSpaceBinding::XRReferenc
 use crate::dom::bindings::inheritance::Castable;
 use crate::dom::bindings::reflector::reflect_dom_object;
 use crate::dom::bindings::root::{DomRoot, MutDom};
-use crate::dom::dompointreadonly::DOMPointReadOnly;
-use crate::dom::window::Window;
+use crate::dom::globalscope::GlobalScope;
 use crate::dom::xrrigidtransform::XRRigidTransform;
 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]
@@ -32,22 +31,7 @@ impl XRReferenceSpace {
     }
 
     #[allow(unused)]
-    pub fn new(
-        global: &Window,
-        session: &XRSession,
-        position: &DOMPointReadOnly,
-        orientation: &DOMPointReadOnly,
-    ) -> DomRoot<XRReferenceSpace> {
-        let transform = XRRigidTransform::new(global, position, orientation);
-        reflect_dom_object(
-            Box::new(XRReferenceSpace::new_inherited(session, &transform)),
-            global,
-            XRReferenceSpaceBinding::Wrap,
-        )
-    }
-
-    #[allow(unused)]
-    pub fn identity(global: &Window, session: &XRSession) -> DomRoot<XRReferenceSpace> {
+    pub fn identity(global: &GlobalScope, session: &XRSession) -> DomRoot<XRReferenceSpace> {
         let transform = XRRigidTransform::identity(global);
         reflect_dom_object(
             Box::new(XRReferenceSpace::new_inherited(session, &transform)),
@@ -71,30 +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()
         }
     }
 }