Merge webxr repository (#35228)

Signed-off-by: Martin Robinson <mrobinson@igalia.com>

components/shared/webxr/device.rs

@@ -0,0 +1,114 @@
+/* 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/. */
+
+//! Traits to be implemented by backends
+
+use crate::ContextId;
+use crate::EnvironmentBlendMode;
+use crate::Error;
+use crate::Event;
+use crate::Floor;
+use crate::Frame;
+use crate::HitTestId;
+use crate::HitTestSource;
+use crate::InputSource;
+use crate::LayerId;
+use crate::LayerInit;
+use crate::Native;
+use crate::Quitter;
+use crate::Sender;
+use crate::Session;
+use crate::SessionBuilder;
+use crate::SessionInit;
+use crate::SessionMode;
+use crate::Viewports;
+
+use euclid::{Point2D, RigidTransform3D};
+
+/// A trait for discovering XR devices
+pub trait DiscoveryAPI<GL>: 'static {
+    fn request_session(
+        &mut self,
+        mode: SessionMode,
+        init: &SessionInit,
+        xr: SessionBuilder<GL>,
+    ) -> Result<Session, Error>;
+    fn supports_session(&self, mode: SessionMode) -> bool;
+}
+
+/// A trait for using an XR device
+pub trait DeviceAPI: 'static {
+    /// Create a new layer
+    fn create_layer(&mut self, context_id: ContextId, init: LayerInit) -> Result<LayerId, Error>;
+
+    /// Destroy a layer
+    fn destroy_layer(&mut self, context_id: ContextId, layer_id: LayerId);
+
+    /// The transform from native coordinates to the floor.
+    fn floor_transform(&self) -> Option<RigidTransform3D<f32, Native, Floor>>;
+
+    fn viewports(&self) -> Viewports;
+
+    /// Begin an animation frame.
+    fn begin_animation_frame(&mut self, layers: &[(ContextId, LayerId)]) -> Option<Frame>;
+
+    /// End an animation frame, render the layer to the device, and block waiting for the next frame.
+    fn end_animation_frame(&mut self, layers: &[(ContextId, LayerId)]);
+
+    /// Inputs registered with the device on initialization. More may be added, which
+    /// should be communicated through a yet-undecided event mechanism
+    fn initial_inputs(&self) -> Vec<InputSource>;
+
+    /// Sets the event handling channel
+    fn set_event_dest(&mut self, dest: Sender<Event>);
+
+    /// Quit the session
+    fn quit(&mut self);
+
+    fn set_quitter(&mut self, quitter: Quitter);
+
+    fn update_clip_planes(&mut self, near: f32, far: f32);
+
+    fn environment_blend_mode(&self) -> EnvironmentBlendMode {
+        // for VR devices, override for AR
+        EnvironmentBlendMode::Opaque
+    }
+
+    fn granted_features(&self) -> &[String];
+
+    fn request_hit_test(&mut self, _source: HitTestSource) {
+        panic!("This device does not support requesting hit tests");
+    }
+
+    fn cancel_hit_test(&mut self, _id: HitTestId) {
+        panic!("This device does not support hit tests");
+    }
+
+    fn update_frame_rate(&mut self, rate: f32) -> f32 {
+        rate
+    }
+
+    fn supported_frame_rates(&self) -> Vec<f32> {
+        Vec::new()
+    }
+
+    fn reference_space_bounds(&self) -> Option<Vec<Point2D<f32, Floor>>> {
+        None
+    }
+}
+
+impl<GL: 'static> DiscoveryAPI<GL> for Box<dyn DiscoveryAPI<GL>> {
+    fn request_session(
+        &mut self,
+        mode: SessionMode,
+        init: &SessionInit,
+        xr: SessionBuilder<GL>,
+    ) -> Result<Session, Error> {
+        (&mut **self).request_session(mode, init, xr)
+    }
+
+    fn supports_session(&self, mode: SessionMode) -> bool {
+        (&**self).supports_session(mode)
+    }
+}