Auto merge of #22528 - Manishearth:webxr, r=jdm,MortimerGoro

Preliminary WebXR support

This implements just enough WebXR to display to 3DOF devices in
immersive mode only.

Couple missing things:

 - [ ] Handling reference spaces (even if just supporting eye-level spaces)
 - [x] Spec links
 - [ ] We enter immersive mode when baseLayer is set, but it seems like
we're supposed to do this when requestSession is called (https://github.com/immersive-web/webxr/issues/453)
 - [ ] VR/XR should block less (https://github.com/servo/servo/issues/22505)
 - [x] More pref-gating
 - [x] `views` is a method instead of an attribute because we don't support FrozenArray

<s>Once I add spec links and pref gating</s> this can be landed as-is for further experimentation.

r? @jdm @MortimerGoro

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components/script/dom/webidls/VR.webidl

@@ -1,11 +0,0 @@
-/* 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://w3c.github.io/webvr/#interface-navigator
-[NoInterfaceObject]
-interface VR {
-  [Pref="dom.webvr.enabled"]
-  Promise<sequence<VRDisplay>> getDisplays();
-  //readonly attribute FrozenArray<VRDisplay> activeVRDisplays;
-};

components/script/dom/webidls/XR.webidl

@@ -0,0 +1,30 @@
+/* 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/#xr-interface
+[SecureContext, Exposed=Window, Pref="dom.webxr.enabled"]
+interface XR: EventTarget {
+  // Methods
+  Promise<void> supportsSessionMode(XRSessionMode mode);
+  Promise<XRSession> requestSession(optional XRSessionCreationOptions parameters);
+
+  // Events
+  // attribute EventHandler ondevicechange;
+};
+
+[SecureContext]
+partial interface Navigator {
+  [SameObject, Pref="dom.webxr.enabled"] readonly attribute XR xr;
+};
+
+enum XRSessionMode {
+  "inline",
+  "immersive-vr",
+  "immersive-ar"
+};
+
+dictionary XRSessionCreationOptions {
+  XRSessionMode mode = "inline";
+  // XRPresentationContext outputContext;
+};

components/script/dom/webidls/XRFrame.webidl

@@ -0,0 +1,13 @@
+/* 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/#xrframe-interface
+
+[SecureContext, Exposed=Window, Pref="dom.webxr.enabled"]
+interface XRFrame {
+  readonly attribute XRSession session;
+
+  XRViewerPose? getViewerPose(optional XRReferenceSpace referenceSpace);
+  // XRInputPose? getInputPose(XRInputSource inputSource, optional XRReferenceSpace referenceSpace);
+};

components/script/dom/webidls/XRLayer.webidl

@@ -0,0 +1,8 @@
+/* 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/#xrlayer-interface
+
+[SecureContext, Exposed=Window, Pref="dom.webxr.enabled"]
+interface XRLayer {};

components/script/dom/webidls/XRReferenceSpace.webidl

@@ -0,0 +1,21 @@
+/* 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/#xrreferencespace-interface
+
+enum XRReferenceSpaceType {
+  "stationary",
+  "bounded",
+  "unbounded"
+};
+
+dictionary XRReferenceSpaceOptions {
+  required XRReferenceSpaceType type;
+};
+
+[SecureContext, Exposed=Window, Pref="dom.webxr.enabled"]
+interface XRReferenceSpace : XRSpace {
+  // attribute XRRigidTransform originOffset;
+  // attribute EventHandler onreset;
+};

components/script/dom/webidls/XRRigidTransform.webidl

@@ -0,0 +1,13 @@
+/* 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/#xrrigidtransform-interface
+
+[SecureContext, Exposed=Window, Pref="dom.webxr.enabled"]
+// [Constructor(optional DOMPointInit position, optional DOMPointInit orientation)]
+interface XRRigidTransform {
+  // readonly attribute DOMPointReadOnly position;
+  // readonly attribute DOMPointReadOnly orientation;
+  // readonly attribute Float32Array matrix;
+};

components/script/dom/webidls/XRSession.webidl

@@ -0,0 +1,45 @@
+/* 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/#xrsession-interface
+
+enum XREnvironmentBlendMode {
+  "opaque",
+  "additive",
+  "alpha-blend",
+};
+
+callback XRFrameRequestCallback = void (DOMHighResTimeStamp time, XRFrame frame);
+
+[SecureContext, Exposed=Window, Pref="dom.webxr.enabled"]
+interface XRSession : EventTarget {
+  // // Attributes
+  readonly attribute XRSessionMode mode;
+  // readonly attribute XRPresentationContext outputContext;
+  // readonly attribute XREnvironmentBlendMode environmentBlendMode;
+
+  attribute double depthNear;
+  attribute double depthFar;
+  attribute XRLayer? baseLayer;
+
+  // // Methods
+  // Promise<XRReferenceSpace> requestReferenceSpace(XRReferenceSpaceType type,
+  //        optional XRReferenceSpaceOptions options);
+
+  // FrozenArray<XRInputSource> getInputSources();
+
+  long requestAnimationFrame(XRFrameRequestCallback callback);
+  void cancelAnimationFrame(long handle);
+
+  // Promise<void> end();
+
+  // // Events
+  // attribute EventHandler onblur;
+  // attribute EventHandler onfocus;
+  // attribute EventHandler onend;
+  // attribute EventHandler onselect;
+  // attribute EventHandler oninputsourceschange;
+  // attribute EventHandler onselectstart;
+  // attribute EventHandler onselectend;
+};

components/script/dom/webidls/XRSpace.webidl

@@ -0,0 +1,10 @@
+/* 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/#xrspace-interface
+
+[SecureContext, Exposed=Window, Pref="dom.webxr.enabled"]
+interface XRSpace : EventTarget {
+  // XRRigidTransform? getTransformTo(XRSpace other);
+};

components/script/dom/webidls/XRStationaryReferenceSpace.webidl

@@ -0,0 +1,20 @@
+/* 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/#xrstationaryreferencespace-interface
+
+enum XRStationaryReferenceSpaceSubtype {
+  "eye-level",
+  "floor-level",
+  "position-disabled"
+};
+
+dictionary XRStationaryReferenceSpaceOptions : XRReferenceSpaceOptions {
+  required XRStationaryReferenceSpaceSubtype subtype;
+};
+
+[SecureContext, Exposed=Window, Pref="dom.webxr.enabled"]
+interface XRStationaryReferenceSpace: XRReferenceSpace {
+  // readonly attribute XRStationaryReferenceSpaceSubtype subtype;
+};

components/script/dom/webidls/XRView.webidl

@@ -0,0 +1,18 @@
+/* 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/#xrview-interface
+
+enum XREye {
+  "left",
+  "right"
+};
+
+[SecureContext, Exposed=Window, Pref="dom.webxr.enabled"]
+interface XRView {
+  readonly attribute XREye eye;
+  readonly attribute Float32Array projectionMatrix;
+  readonly attribute Float32Array viewMatrix;
+  // readonly attribute XRRigidTransform transform;
+};

components/script/dom/webidls/XRViewerPose.webidl

@@ -0,0 +1,14 @@
+/* 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/#xrviewerpose-interface
+
+[SecureContext, Exposed=Window, Pref="dom.webxr.enabled"]
+interface XRViewerPose {
+  // readonly attribute XRRigidTransform transform;
+  // readonly attribute FrozenArray<XRView> views;
+  // workaround until we have FrozenArray
+  // see https://github.com/servo/servo/issues/10427#issuecomment-449593626
+  readonly attribute any views;
+};

components/script/dom/webidls/XRViewport.webidl

@@ -0,0 +1,13 @@
+/* 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, Pref="dom.webxr.enabled"]
+interface XRViewport {
+  readonly attribute long x;
+  readonly attribute long y;
+  readonly attribute long width;
+  readonly attribute long height;
+};

components/script/dom/webidls/XRWebGLLayer.webidl

@@ -0,0 +1,43 @@
+/* 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/#xrwebgllayer-interface
+
+// typedef (WebGLRenderingContext or
+//          WebGL2RenderingContext) XRWebGLRenderingContext;
+
+typedef WebGLRenderingContext XRWebGLRenderingContext;
+
+dictionary XRWebGLLayerInit {
+  boolean antialias = true;
+  boolean depth = true;
+  boolean stencil = false;
+  boolean alpha = true;
+  // double framebufferScaleFactor = 1.0;
+};
+
+[SecureContext, Exposed=Window, Constructor(XRSession session,
+            XRWebGLRenderingContext context,
+            optional XRWebGLLayerInit layerInit),
+    Pref="dom.webxr.enabled"]
+interface XRWebGLLayer : XRLayer {
+  // // Attributes
+  readonly attribute XRWebGLRenderingContext context;
+
+  readonly attribute boolean antialias;
+  readonly attribute boolean depth;
+  readonly attribute boolean stencil;
+  readonly attribute boolean alpha;
+
+  // readonly attribute WebGLFramebuffer framebuffer;
+  // readonly attribute unsigned long framebufferWidth;
+  // readonly attribute unsigned long framebufferHeight;
+
+  // // Methods
+  XRViewport? getViewport(XRView view);
+  // void requestViewportScaling(double viewportScaleFactor);
+
+  // // Static Methods
+  // static double getNativeFramebufferScaleFactor(XRSession session);
+};