Support for ExternalVR implementation

components/compositing/windowing.rs

@@ -14,6 +14,7 @@ use script_traits::{MouseButton, TouchEventType, TouchId};
 use servo_geometry::DeviceIndependentPixel;
 use servo_url::ServoUrl;
 use std::fmt::{Debug, Error, Formatter};
+use std::os::raw::c_void;
 #[cfg(feature = "gl")]
 use std::rc::Rc;
 use style_traits::DevicePixel;
@@ -145,6 +146,11 @@ pub trait WindowMethods {
     /// will want to avoid blocking on UI events, and just
     /// run the event loop at the vsync interval.
     fn set_animation_state(&self, _state: AnimationState);
+    /// Provide a c_void pointer to a VRExternal shared memory.
+    /// See: https://github.com/servo/rust-webvr/tree/master/rust-webvr/src/api/vrexternal
+    fn get_vrexternal_pointer(&self) -> Option<*mut c_void> {
+        None
+    }
 }
 
 #[derive(Clone, Copy, Debug)]

components/servo/lib.rs

@@ -107,7 +107,7 @@ use std::cmp::max;
 use std::path::PathBuf;
 use std::rc::Rc;
 use webrender::{RendererKind, ShaderPrecacheFlags};
-use webvr::{WebVRCompositorHandler, WebVRThread};
+use webvr::{VRExternalShmemPtr, WebVRCompositorHandler, WebVRThread};
 
 pub use gleam::gl;
 pub use msg::constellation_msg::TopLevelBrowsingContextId as BrowserId;
@@ -216,6 +216,10 @@ where
         // can't defer it after `create_constellation` has started.
         script::init();
 
+        let webvr_shmem = window
+            .get_vrexternal_pointer()
+            .map(|ptr| VRExternalShmemPtr::new(ptr));
+
         // Create the constellation, which maintains the engine
         // pipelines, including the script and layout threads, as well
         // as the navigation context.
@@ -232,6 +236,7 @@ where
             webrender_document,
             webrender_api_sender,
             window.gl(),
+            webvr_shmem,
         );
 
         // Send the constellation's swmanager sender to service worker manager thread
@@ -510,6 +515,7 @@ fn create_constellation(
     webrender_document: webrender_api::DocumentId,
     webrender_api_sender: webrender_api::RenderApiSender,
     window_gl: Rc<dyn gl::Gl>,
+    webvr_shmem: Option<VRExternalShmemPtr>,
 ) -> (Sender<ConstellationMsg>, SWManagerSenders) {
     let bluetooth_thread: IpcSender<BluetoothRequest> =
         BluetoothThreadFactory::new(embedder_proxy.clone());
@@ -532,7 +538,7 @@ fn create_constellation(
     let (webvr_chan, webvr_constellation_sender, webvr_compositor) = if PREFS.is_webvr_enabled() {
         // WebVR initialization
         let (mut handler, sender) = WebVRCompositorHandler::new();
-        let (webvr_thread, constellation_sender) = WebVRThread::spawn(sender);
+        let (webvr_thread, constellation_sender) = WebVRThread::spawn(sender, webvr_shmem);
         handler.set_webvr_thread_sender(webvr_thread.clone());
         (
             Some(webvr_thread),

components/webvr/Cargo.toml

@@ -21,7 +21,7 @@ euclid = "0.19"
 ipc-channel = "0.11"
 log = "0.4"
 msg = {path = "../msg"}
-rust-webvr = {version = "0.9", features = ["openvr"]}
+rust-webvr = {version = "0.9", features = ["openvr", "vrexternal"]}
 script_traits = {path = "../script_traits"}
 servo_config = {path = "../config"}
 webvr_traits = {path = "../webvr_traits" }

components/webvr/lib.rs

@@ -9,3 +9,4 @@ extern crate log;
 
 mod webvr_thread;
 pub use crate::webvr_thread::{WebVRCompositorHandler, WebVRThread};
+pub use rust_webvr::api::VRExternalShmemPtr;

components/webvr/webvr_thread.rs

@@ -2,6 +2,7 @@
  * 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::VRExternalShmemPtr;
 use canvas_traits::webgl;
 use crossbeam_channel::{unbounded, Receiver, Sender};
 use euclid::Size2D;
@@ -52,9 +53,13 @@ impl WebVRThread {
         sender: IpcSender<WebVRMsg>,
         constellation_chan: Sender<ConstellationMsg>,
         vr_compositor_chan: WebVRCompositorSender,
+        webvr_shmem: Option<VRExternalShmemPtr>,
     ) -> WebVRThread {
         let mut service = VRServiceManager::new();
         service.register_defaults();
+        if let Some(ptr) = webvr_shmem {
+            service.register_vrexternal(ptr);
+        }
         WebVRThread {
             receiver: receiver,
             sender: sender,
@@ -69,6 +74,7 @@ impl WebVRThread {
 
     pub fn spawn(
         vr_compositor_chan: WebVRCompositorSender,
+        webvr_shmem: Option<VRExternalShmemPtr>,
     ) -> (IpcSender<WebVRMsg>, Sender<Sender<ConstellationMsg>>) {
         let (sender, receiver) = ipc::channel().unwrap();
         let (constellation_sender, constellation_receiver) = unbounded();
@@ -82,6 +88,7 @@ impl WebVRThread {
                     sender_clone,
                     constellation_chan,
                     vr_compositor_chan,
+                    webvr_shmem,
                 )
                 .start();
             })
@@ -157,7 +164,7 @@ impl WebVRThread {
     ) {
         match self.access_check(pipeline, display_id) {
             Ok(display) => sender
-                .send(Ok(display.borrow().inmediate_frame_data(near, far)))
+                .send(Ok(display.borrow().immediate_frame_data(near, far)))
                 .unwrap(),
             Err(msg) => sender.send(Err(msg.into())).unwrap(),
         }