Update to treat view transforms as native-relative

Cargo.lock

@@ -6471,7 +6471,7 @@ dependencies = [
 [[package]]
 name = "webxr"
 version = "0.0.1"
-source = "git+https://github.com/servo/webxr#3f754a11eb3e9771f6020ec5a25ae94ed1e11f07"
+source = "git+https://github.com/servo/webxr#0d8d2affc4da259b88d251ab49c0bbcbe96acf4d"
 dependencies = [
  "android_injected_glue",
  "bindgen",
@@ -6494,7 +6494,7 @@ dependencies = [
 [[package]]
 name = "webxr-api"
 version = "0.0.1"
-source = "git+https://github.com/servo/webxr#3f754a11eb3e9771f6020ec5a25ae94ed1e11f07"
+source = "git+https://github.com/servo/webxr#0d8d2affc4da259b88d251ab49c0bbcbe96acf4d"
 dependencies = [
  "euclid",
  "ipc-channel",

components/script/dom/xrframe.rs

@@ -80,8 +80,8 @@ impl XRFrameMethods for XRFrame {
             return Err(Error::InvalidState);
         }
 
-        let pose = if let Some(pose) = reference.get_viewer_pose(&self.data) {
-            pose
+        let to_base = if let Some(to_base) = reference.get_base_transform(&self.data) {
+            to_base
         } else {
             return Ok(None);
         };
@@ -93,7 +93,7 @@ impl XRFrameMethods for XRFrame {
         Ok(Some(XRViewerPose::new(
             &self.global(),
             &self.session,
-            pose,
+            to_base,
             viewer_pose,
         )))
     }

components/script/dom/xrreferencespace.rs

@@ -9,11 +9,11 @@ use crate::dom::bindings::reflector::{reflect_dom_object, DomObject};
 use crate::dom::bindings::root::{Dom, DomRoot};
 use crate::dom::globalscope::GlobalScope;
 use crate::dom::xrrigidtransform::XRRigidTransform;
-use crate::dom::xrsession::{cast_transform, ApiPose, ApiViewerPose, XRSession};
+use crate::dom::xrsession::{cast_transform, ApiPose, BaseTransform, XRSession};
 use crate::dom::xrspace::XRSpace;
 use dom_struct::dom_struct;
 use euclid::RigidTransform3D;
-use webxr_api::{BaseSpace, Frame, Space};
+use webxr_api::{self, Frame, Space};
 
 #[dom_struct]
 pub struct XRReferenceSpace {
@@ -60,9 +60,9 @@ impl XRReferenceSpace {
 
     pub fn space(&self) -> Space {
         let base = match self.ty {
-            XRReferenceSpaceType::Local => BaseSpace::Local,
-            XRReferenceSpaceType::Viewer => BaseSpace::Viewer,
-            XRReferenceSpaceType::Local_floor => BaseSpace::Floor,
+            XRReferenceSpaceType::Local => webxr_api::BaseSpace::Local,
+            XRReferenceSpaceType::Viewer => webxr_api::BaseSpace::Viewer,
+            XRReferenceSpaceType::Local_floor => webxr_api::BaseSpace::Floor,
             _ => panic!("unsupported reference space found"),
         };
         let offset = self.offset.transform();
@@ -85,58 +85,13 @@ impl XRReferenceSpaceMethods for XRReferenceSpace {
 }
 
 impl XRReferenceSpace {
-    /// Gets pose of the viewer with respect to this space
+    /// Get a transform that can be used to locate the base space
     ///
-    /// This is equivalent to `get_pose(self).inverse() * get_pose(viewerSpace)` (in column vector notation),
-    /// however we specialize it to be efficient
-    pub fn get_viewer_pose(&self, base_pose: &Frame) -> Option<ApiViewerPose> {
-        let pose = self.get_unoffset_viewer_pose(base_pose)?;
-        // in column-vector notation,
-        // get_viewer_pose(space) = get_pose(space).inverse() * get_pose(viewer_space)
-        //                        = (get_unoffset_pose(space) * offset).inverse() * get_pose(viewer_space)
-        //                        = offset.inverse() * get_unoffset_pose(space).inverse() * get_pose(viewer_space)
-        //                        = offset.inverse() * get_unoffset_viewer_pose(space)
-        let offset = self.offset.transform();
-        let inverse = offset.inverse();
-        Some(inverse.pre_transform(&pose))
-    }
-
-    /// Gets pose of the viewer with respect to this space
-    ///
-    /// Does not apply originOffset, use get_viewer_pose instead if you need it
-    pub fn get_unoffset_viewer_pose(&self, base_pose: &Frame) -> Option<ApiViewerPose> {
-        // all math is in column-vector notation
-        // we use the following equation to verify correctness here:
-        // get_viewer_pose(space) = get_pose(space).inverse() * get_pose(viewer_space)
-        match self.ty {
-            XRReferenceSpaceType::Local => {
-                // get_viewer_pose(eye_level) = get_pose(eye_level).inverse() * get_pose(viewer_space)
-                //                            = I * viewer_pose
-                //                            = viewer_pose
-                let viewer_pose: ApiViewerPose = cast_transform(base_pose.pose.as_ref()?.transform);
-
-                // we get viewer poses in eye-level space by default
-                Some(viewer_pose)
-            },
-            XRReferenceSpaceType::Local_floor => {
-                // get_viewer_pose(floor_level) = get_pose(floor_level).inverse() * get_pose(viewer_space)
-                //                            = floor_to_native.inverse() * viewer_pose
-                //                            = native_to_floor * viewer_pose
-                let viewer_pose = base_pose.pose.as_ref()?.transform;
-                let native_to_floor = self
-                    .upcast::<XRSpace>()
-                    .session()
-                    .with_session(|s| s.floor_transform())?;
-
-                Some(cast_transform(native_to_floor.pre_transform(&viewer_pose)))
-            },
-            XRReferenceSpaceType::Viewer => {
-                // This reference space follows the viewer around, so the viewer is
-                // always at an identity transform with respect to it
-                Some(RigidTransform3D::identity())
-            },
-            _ => unimplemented!(),
-        }
+    /// This is equivalent to `get_pose(self).inverse()` (in column vector notation),
+    /// but with better types
+    pub fn get_base_transform(&self, base_pose: &Frame) -> Option<BaseTransform> {
+        let pose = self.get_pose(base_pose)?;
+        Some(pose.inverse().cast_unit())
     }
 
     /// Gets pose represented by this space

components/script/dom/xrsession.rs

@@ -791,11 +791,14 @@ impl XRSessionMethods for XRSession {
 
 // The pose of an object in native-space. Should never be exposed.
 pub type ApiPose = RigidTransform3D<f32, ApiSpace, webxr_api::Native>;
-// The pose of the viewer in some api-space.
-pub type ApiViewerPose = RigidTransform3D<f32, webxr_api::Viewer, ApiSpace>;
 // A transform between objects in some API-space
 pub type ApiRigidTransform = RigidTransform3D<f32, ApiSpace, ApiSpace>;
 
+#[derive(Clone, Copy)]
+pub struct BaseSpace;
+
+pub type BaseTransform = RigidTransform3D<f32, webxr_api::Native, BaseSpace>;
+
 #[allow(unsafe_code)]
 pub fn cast_transform<T, U, V, W>(
     transform: RigidTransform3D<f32, T, U>,

components/script/dom/xrview.rs

@@ -9,9 +9,10 @@ use crate::dom::bindings::root::{Dom, DomRoot};
 use crate::dom::bindings::utils::create_typed_array;
 use crate::dom::globalscope::GlobalScope;
 use crate::dom::xrrigidtransform::XRRigidTransform;
-use crate::dom::xrsession::{cast_transform, ApiViewerPose, XRSession};
+use crate::dom::xrsession::{cast_transform, BaseSpace, BaseTransform, XRSession};
 use crate::script_runtime::JSContext;
 use dom_struct::dom_struct;
+use euclid::RigidTransform3D;
 use js::jsapi::{Heap, JSObject};
 use std::ptr::NonNull;
 use webxr_api::{ApiSpace, View};
@@ -54,15 +55,9 @@ impl XRView {
         view: &View<V>,
         eye: XREye,
         viewport_index: usize,
-        pose: &ApiViewerPose,
+        to_base: &BaseTransform,
     ) -> DomRoot<XRView> {
-        // XXXManishearth compute and cache projection matrices on the Display
-
-        // this transform is the pose of the viewer in the eye space, i.e. it is the transform
-        // from the viewer space to the eye space. We invert it to get the pose of the eye in the viewer space.
-        let offset = view.transform.inverse();
-
-        let transform = pose.pre_transform(&offset);
+        let transform: RigidTransform3D<f32, V, BaseSpace> = to_base.pre_transform(&view.transform);
         let transform = XRRigidTransform::new(global, cast_transform(transform));
 
         reflect_dom_object(

components/script/dom/xrviewerpose.rs

@@ -9,15 +9,16 @@ use crate::dom::bindings::root::DomRoot;
 use crate::dom::globalscope::GlobalScope;
 use crate::dom::xrpose::XRPose;
 use crate::dom::xrrigidtransform::XRRigidTransform;
-use crate::dom::xrsession::{cast_transform, ApiViewerPose, XRSession};
+use crate::dom::xrsession::{cast_transform, BaseSpace, BaseTransform, XRSession};
 use crate::dom::xrview::XRView;
 use crate::realms::enter_realm;
 use crate::script_runtime::JSContext;
 use dom_struct::dom_struct;
+use euclid::RigidTransform3D;
 use js::conversions::ToJSValConvertible;
 use js::jsapi::Heap;
 use js::jsval::{JSVal, UndefinedValue};
-use webxr_api::{ViewerPose, Views};
+use webxr_api::{Viewer, ViewerPose, Views};
 
 #[dom_struct]
 pub struct XRViewerPose {
@@ -38,7 +39,7 @@ impl XRViewerPose {
     pub fn new(
         global: &GlobalScope,
         session: &XRSession,
-        pose: ApiViewerPose,
+        to_base: BaseTransform,
         viewer_pose: &ViewerPose,
     ) -> DomRoot<XRViewerPose> {
         let _ac = enter_realm(&*global);
@@ -50,29 +51,64 @@ impl XRViewerPose {
                 &session.inline_view(),
                 XREye::None,
                 0,
-                &pose,
+                &to_base,
+            )),
+            Views::Mono(view) => views.push(XRView::new(
+                global,
+                session,
+                &view,
+                XREye::None,
+                0,
+                &to_base,
             )),
-            Views::Mono(view) => {
-                views.push(XRView::new(global, session, &view, XREye::None, 0, &pose))
-            },
             Views::Stereo(left, right) => {
-                views.push(XRView::new(global, session, &left, XREye::Left, 0, &pose));
-                views.push(XRView::new(global, session, &right, XREye::Right, 1, &pose));
+                views.push(XRView::new(
+                    global,
+                    session,
+                    &left,
+                    XREye::Left,
+                    0,
+                    &to_base,
+                ));
+                views.push(XRView::new(
+                    global,
+                    session,
+                    &right,
+                    XREye::Right,
+                    1,
+                    &to_base,
+                ));
             },
             Views::StereoCapture(left, right, third_eye) => {
-                views.push(XRView::new(global, session, &left, XREye::Left, 0, &pose));
-                views.push(XRView::new(global, session, &right, XREye::Right, 1, &pose));
+                views.push(XRView::new(
+                    global,
+                    session,
+                    &left,
+                    XREye::Left,
+                    0,
+                    &to_base,
+                ));
+                views.push(XRView::new(
+                    global,
+                    session,
+                    &right,
+                    XREye::Right,
+                    1,
+                    &to_base,
+                ));
                 views.push(XRView::new(
                     global,
                     session,
                     &third_eye,
                     XREye::None,
                     2,
-                    &pose,
+                    &to_base,
                 ));
             },
         };
-        let transform = XRRigidTransform::new(global, cast_transform(pose));
+        let transform: RigidTransform3D<f32, Viewer, BaseSpace> =
+            to_base.pre_transform(&viewer_pose.transform);
+        let transform = XRRigidTransform::new(global, cast_transform(transform));
         let pose = reflect_dom_object(Box::new(XRViewerPose::new_inherited(&transform)), global);
 
         let cx = global.get_cx();