webxr: Update XRSession to latest spec (#33059)

* Add missing XRSession members, initial implementations

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

* Implement supportedFramerates getter

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

* Implement framerate changes, add spec links

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

* Update WPT expectations

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

* ./mach fmt

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

* Add missing spec link

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

---------

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

1 files changed, 125 insertions, 1 deletions

diff --git a/components/script/dom/xrsession.rs b/components/script/dom/xrsession.rs
index 9b42c146a0f..6cfd8fda59e 100644
--- a/components/script/dom/xrsession.rs
+++ b/components/script/dom/xrsession.rs
@@ -5,15 +5,19 @@
 use std::cell::Cell;
 use std::collections::HashMap;
 use std::f64::consts::{FRAC_PI_2, PI};
-use std::mem;
 use std::rc::Rc;
+use std::{mem, ptr};
 
 use dom_struct::dom_struct;
 use euclid::{RigidTransform3D, Transform3D, Vector3D};
 use ipc_channel::ipc::IpcReceiver;
 use ipc_channel::router::ROUTER;
+use js::jsapi::JSObject;
+use js::jsval::JSVal;
+use js::typedarray::Float32Array;
 use metrics::ToMs;
 use profile_traits::ipc;
+use servo_atoms::Atom;
 use webxr_api::{
     self, util, ApiSpace, ContextId as WebXRContextId, Display, EntityTypes, EnvironmentBlendMode,
     Event as XREvent, Frame, FrameUpdateEvent, HitTestId, HitTestSource, InputFrame, InputId, Ray,
@@ -21,6 +25,7 @@ use webxr_api::{
 };
 
 use super::bindings::trace::HashMapTracedValues;
+use crate::dom::bindings::buffer_source::create_buffer_source;
 use crate::dom::bindings::callback::ExceptionHandling;
 use crate::dom::bindings::cell::DomRefCell;
 use crate::dom::bindings::codegen::Bindings::NavigatorBinding::Navigator_Binding::NavigatorMethods;
@@ -39,9 +44,11 @@ use crate::dom::bindings::codegen::Bindings::XRSessionBinding::{
 use crate::dom::bindings::codegen::Bindings::XRSystemBinding::XRSessionMode;
 use crate::dom::bindings::error::{Error, ErrorResult};
 use crate::dom::bindings::inheritance::Castable;
+use crate::dom::bindings::num::Finite;
 use crate::dom::bindings::refcounted::Trusted;
 use crate::dom::bindings::reflector::{reflect_dom_object, DomObject};
 use crate::dom::bindings::root::{Dom, DomRoot, MutDom, MutNullableDom};
+use crate::dom::bindings::utils::to_frozen_array;
 use crate::dom::event::Event;
 use crate::dom::eventtarget::EventTarget;
 use crate::dom::globalscope::GlobalScope;
@@ -56,6 +63,7 @@ use crate::dom::xrrenderstate::XRRenderState;
 use crate::dom::xrsessionevent::XRSessionEvent;
 use crate::dom::xrspace::XRSpace;
 use crate::realms::InRealm;
+use crate::script_runtime::JSContext;
 use crate::task_source::TaskSource;
 
 #[dom_struct]
@@ -97,6 +105,9 @@ pub struct XRSession {
     #[ignore_malloc_size_of = "defined in webxr"]
     #[no_trace]
     input_frames: DomRefCell<HashMap<InputId, InputFrame>>,
+    framerate: Cell<f32>,
+    #[ignore_malloc_size_of = "promises are hard"]
+    update_framerate_promise: DomRefCell<Option<Rc<Promise>>>,
 }
 
 impl XRSession {
@@ -128,6 +139,8 @@ impl XRSession {
             pending_hit_test_promises: DomRefCell::new(HashMapTracedValues::new()),
             outside_raf: Cell::new(true),
             input_frames: DomRefCell::new(HashMap::new()),
+            framerate: Cell::new(0.0),
+            update_framerate_promise: DomRefCell::new(None),
         }
     }
 
@@ -543,6 +556,24 @@ impl XRSession {
             _ => self.session.borrow_mut().apply_event(event),
         }
     }
+
+    /// <https://www.w3.org/TR/webxr/#apply-the-nominal-frame-rate>
+    fn apply_nominal_framerate(&self, rate: f32) {
+        if self.framerate.get() == rate || self.ended.get() {
+            return;
+        }
+
+        self.framerate.set(rate);
+
+        let event = XRSessionEvent::new(
+            &self.global(),
+            Atom::from("frameratechange"),
+            false,
+            false,
+            self,
+        );
+        event.upcast::<Event>().fire(self.upcast());
+    }
 }
 
 impl XRSessionMethods for XRSession {
@@ -581,6 +612,9 @@ impl XRSessionMethods for XRSession {
         SetOninputsourceschange
     );
 
+    // https://www.w3.org/TR/webxr/#dom-xrsession-onframeratechange
+    event_handler!(frameratechange, GetOnframeratechange, SetOnframeratechange);
+
     // https://immersive-web.github.io/webxr/#dom-xrsession-renderstate
     fn RenderState(&self) -> DomRoot<XRRenderState> {
         self.active_render_state.get()
@@ -881,6 +915,96 @@ impl XRSessionMethods for XRSession {
         // this should always be world space
         XRInteractionMode::World_space
     }
+
+    /// <https://www.w3.org/TR/webxr/#dom-xrsession-framerate>
+    fn GetFrameRate(&self) -> Option<Finite<f32>> {
+        let session = self.session.borrow();
+        if self.mode == XRSessionMode::Inline || session.supported_frame_rates().is_empty() {
+            None
+        } else {
+            Finite::new(self.framerate.get())
+        }
+    }
+
+    /// <https://www.w3.org/TR/webxr/#dom-xrsession-supportedframerates>
+    fn GetSupportedFrameRates(&self, cx: JSContext) -> Option<Float32Array> {
+        let session = self.session.borrow();
+        if self.mode == XRSessionMode::Inline || session.supported_frame_rates().is_empty() {
+            None
+        } else {
+            let framerates = session.supported_frame_rates();
+            rooted!(in (*cx) let mut array = ptr::null_mut::<JSObject>());
+            Some(
+                create_buffer_source(cx, framerates, array.handle_mut())
+                    .expect("Failed to construct supported frame rates array"),
+            )
+        }
+    }
+
+    /// <https://www.w3.org/TR/webxr/#dom-xrsession-enabledfeatures>
+    fn EnabledFeatures(&self, cx: JSContext) -> JSVal {
+        let session = self.session.borrow();
+        let features = session.granted_features();
+        to_frozen_array(features, cx)
+    }
+
+    /// <https://www.w3.org/TR/webxr/#dom-xrsession-issystemkeyboardsupported>
+    fn IsSystemKeyboardSupported(&self) -> bool {
+        // Support for this only exists on Meta headsets (no desktop support)
+        // so this will always be false until that changes
+        false
+    }
+
+    /// <https://www.w3.org/TR/webxr/#dom-xrsession-updatetargetframerate>
+    fn UpdateTargetFrameRate(&self, rate: Finite<f32>, comp: InRealm) -> Rc<Promise> {
+        let mut session = self.session.borrow_mut();
+        let supported_frame_rates = session.supported_frame_rates();
+        let promise = Promise::new_in_current_realm(comp);
+
+        if self.mode == XRSessionMode::Inline ||
+            supported_frame_rates.is_empty() ||
+            self.ended.get()
+        {
+            promise.reject_error(Error::InvalidState);
+            return promise;
+        }
+
+        if !supported_frame_rates.contains(&*rate) {
+            promise.reject_error(Error::Type("Provided framerate not supported".into()));
+            return promise;
+        }
+
+        *self.update_framerate_promise.borrow_mut() = Some(promise.clone());
+
+        let this = Trusted::new(self);
+        let global = self.global();
+        let window = global.as_window();
+        let (task_source, canceller) = window
+            .task_manager()
+            .dom_manipulation_task_source_with_canceller();
+        let (sender, receiver) = ipc::channel(global.time_profiler_chan().clone()).unwrap();
+
+        ROUTER.add_route(
+            receiver.to_opaque(),
+            Box::new(move |message| {
+                let this = this.clone();
+                let _ = task_source.queue_with_canceller(
+                    task!(update_session_framerate: move || {
+                        let session = this.root();
+                        session.apply_nominal_framerate(message.to().unwrap());
+                        if let Some(promise) = session.update_framerate_promise.borrow_mut().take() {
+                            promise.resolve_native(&());
+                        };
+                    }),
+                    &canceller,
+                );
+            }),
+        );
+
+        session.update_frame_rate(*rate, sender);
+
+        promise
+    }
 }
 
 // The pose of an object in native-space. Should never be exposed.