Support fetching viewport info

components/script/dom/mod.rs

@@ -527,4 +527,5 @@ pub mod xrspace;
 pub mod xrstationaryreferencespace;
 pub mod xrview;
 pub mod xrviewerpose;
+pub mod xrviewport;
 pub mod xrwebgllayer;

components/script/dom/webglrenderingcontext.rs

@@ -157,6 +157,7 @@ pub struct WebGLRenderingContext {
     current_scissor: Cell<(i32, i32, u32, u32)>,
     #[ignore_malloc_size_of = "Because it's small"]
     current_clear_color: Cell<(f32, f32, f32, f32)>,
+    size: Cell<Size2D<u32>>,
     extension_manager: WebGLExtensions,
     capabilities: Capabilities,
     default_vao: DomOnceCell<WebGLVertexArrayObjectOES>,
@@ -211,6 +212,7 @@ impl WebGLRenderingContext {
                 current_program: MutNullableDom::new(None),
                 current_vertex_attrib_0: Cell::new((0f32, 0f32, 0f32, 1f32)),
                 current_scissor: Cell::new((0, 0, size.width, size.height)),
+                size: Cell::new(size),
                 current_clear_color: Cell::new((0.0, 0.0, 0.0, 0.0)),
                 extension_manager: WebGLExtensions::new(webgl_version),
                 capabilities: Default::default(),
@@ -266,6 +268,7 @@ impl WebGLRenderingContext {
     pub fn recreate(&self, size: Size2D<u32>) {
         let (sender, receiver) = webgl_channel().unwrap();
         self.webgl_sender.send_resize(size, sender).unwrap();
+        self.size.set(size);
 
         if let Err(msg) = receiver.recv().unwrap() {
             error!("Error resizing WebGLContext: {}", msg);
@@ -340,6 +343,10 @@ impl WebGLRenderingContext {
         }
     }
 
+    pub fn size(&self) -> Size2D<u32> {
+        self.size.get()
+    }
+
     // Helper function for validating framebuffer completeness in
     // calls touching the framebuffer.  From the GLES 2.0.25 spec,
     // page 119:

components/script/dom/webidls/XRSession.webidl

@@ -10,6 +10,8 @@ enum XREnvironmentBlendMode {
   "alpha-blend",
 };
 
+callback XRFrameRequestCallback = void (DOMHighResTimeStamp time, XRFrame frame);
+
 [SecureContext, Exposed=Window] interface XRSession : EventTarget {
   // // Attributes
   readonly attribute XRSessionMode mode;

components/script/dom/webidls/XRView.webidl

@@ -10,7 +10,7 @@ enum XREye {
 };
 
 [SecureContext, Exposed=Window] interface XRView {
-  // readonly attribute XREye eye;
+  readonly attribute XREye eye;
   // readonly attribute Float32Array projectionMatrix;
   // readonly attribute Float32Array viewMatrix;
   // readonly attribute XRRigidTransform transform;

components/script/dom/webidls/XRViewport.webidl

@@ -0,0 +1,12 @@
+/* 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/#xrviewport-interface
+
+[SecureContext, Exposed=Window] interface XRViewport {
+  readonly attribute long x;
+  readonly attribute long y;
+  readonly attribute long width;
+  readonly attribute long height;
+};

components/script/dom/webidls/XRWebGLLayer.webidl

@@ -34,7 +34,7 @@ interface XRWebGLLayer : XRLayer {
   // readonly attribute unsigned long framebufferHeight;
 
   // // Methods
-  // XRViewport? getViewport(XRView view);
+  XRViewport? getViewport(XRView view);
   // void requestViewportScaling(double viewportScaleFactor);
 
   // // Static Methods

components/script/dom/xrview.rs

@@ -3,28 +3,45 @@
  * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
 
 use crate::dom::bindings::codegen::Bindings::XRViewBinding;
+use crate::dom::bindings::codegen::Bindings::XRViewBinding::{XREye, XRViewMethods};
 use crate::dom::bindings::reflector::{reflect_dom_object, Reflector};
-use crate::dom::bindings::root::DomRoot;
+use crate::dom::bindings::root::{Dom, DomRoot};
 use crate::dom::globalscope::GlobalScope;
+use crate::dom::xrsession::XRSession;
 use dom_struct::dom_struct;
 
 #[dom_struct]
 pub struct XRView {
     reflector_: Reflector,
+    session: Dom<XRSession>,
+    eye: XREye,
 }
 
 impl XRView {
-    fn new_inherited() -> XRView {
+    fn new_inherited(session: &XRSession, eye: XREye) -> XRView {
         XRView {
             reflector_: Reflector::new(),
+            session: Dom::from_ref(session),
+            eye
         }
     }
 
-    pub fn new(global: &GlobalScope) -> DomRoot<XRView> {
+    pub fn new(global: &GlobalScope, session: &XRSession, eye: XREye) -> DomRoot<XRView> {
         reflect_dom_object(
-            Box::new(XRView::new_inherited()),
+            Box::new(XRView::new_inherited(session, eye)),
             global,
             XRViewBinding::Wrap,
         )
     }
+
+    pub fn session(&self) -> &XRSession {
+        &self.session
+    }
 }
+
+impl XRViewMethods for XRView {
+    /// https://immersive-web.github.io/webxr/#dom-xrview-eye
+    fn Eye(&self) -> XREye {
+        self.eye
+    }
+}

components/script/dom/xrviewport.rs

@@ -0,0 +1,59 @@
+/* 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::XRViewportBinding;
+use crate::dom::bindings::codegen::Bindings::XRViewportBinding::XRViewportMethods;
+use crate::dom::bindings::reflector::{reflect_dom_object, Reflector};
+use crate::dom::bindings::root::DomRoot;
+use crate::dom::globalscope::GlobalScope;
+use dom_struct::dom_struct;
+
+#[dom_struct]
+pub struct XRViewport {
+    reflector_: Reflector,
+    x: u32,
+    y: u32,
+    width: u32,
+    height: u32,
+}
+
+impl XRViewport {
+    fn new_inherited(x: u32, y: u32, width: u32, height: u32) -> XRViewport {
+        XRViewport {
+            reflector_: Reflector::new(),
+            x, y, width, height
+        }
+    }
+
+    pub fn new(global: &GlobalScope,
+               x: u32, y: u32, width: u32, height: u32) -> DomRoot<XRViewport> {
+        reflect_dom_object(
+            Box::new(XRViewport::new_inherited(x, y, width, height)),
+            global,
+            XRViewportBinding::Wrap,
+        )
+    }
+}
+
+impl XRViewportMethods for XRViewport {
+    /// https://immersive-web.github.io/webxr/#dom-xrviewport-x
+    fn X(&self) -> i32 {
+        self.x as i32
+    }
+
+    /// https://immersive-web.github.io/webxr/#dom-xrviewport-y
+    fn Y(&self) -> i32 {
+        self.y as i32
+    }
+
+    /// https://immersive-web.github.io/webxr/#dom-xrviewport-width
+    fn Width(&self) -> i32 {
+        self.height as i32
+    }
+
+    /// https://immersive-web.github.io/webxr/#dom-xrviewport-height
+    fn Height(&self) -> i32 {
+        self.height as i32
+    }
+}

components/script/dom/xrwebgllayer.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::dom::bindings::codegen::Bindings::XRViewBinding::{XREye, XRViewMethods};
 use crate::dom::bindings::codegen::Bindings::XRWebGLLayerBinding;
 use crate::dom::bindings::codegen::Bindings::XRWebGLLayerBinding::XRWebGLLayerMethods;
 use crate::dom::bindings::codegen::Bindings::XRWebGLLayerBinding::XRWebGLLayerInit;
@@ -13,6 +14,8 @@ use crate::dom::webglrenderingcontext::WebGLRenderingContext;
 use crate::dom::window::Window;
 use crate::dom::xrlayer::XRLayer;
 use crate::dom::xrsession::XRSession;
+use crate::dom::xrview::XRView;
+use crate::dom::xrviewport::XRViewport;
 use dom_struct::dom_struct;
 
 use std::cell::Cell;
@@ -78,5 +81,23 @@ impl XRWebGLLayerMethods for XRWebGLLayer {
     fn Context(&self) -> DomRoot<WebGLRenderingContext> {
         DomRoot::from_ref(&self.context)
     }
+
+    fn GetViewport(&self, view: &XRView) -> Option<DomRoot<XRViewport>> {
+        if self.session != view.session() {
+            return None;
+        }
+
+        let size = self.context.size();
+
+        let x = if view.Eye() == XREye::Left {
+            0
+        } else {
+            size.width / 2
+        };
+        // XXXManishearth this assumes the WebVR default of canvases being cut in half
+        // which need not be generally true for all devices, and will not work in
+        // inline VR mode
+        Some(XRViewport::new(&self.global(), x, 0, size.width / 2, size.height))
+    }
 }