Added first-cut implementation of XR layers

components/script/dom/xrrenderstate.rs

@@ -2,15 +2,18 @@
  * 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::cell::DomRefCell;
 use crate::dom::bindings::codegen::Bindings::XRRenderStateBinding::XRRenderStateMethods;
+use crate::dom::bindings::codegen::UnionTypes::XRWebGLLayerOrXRLayer as RootedXRWebGLLayerOrXRLayer;
 use crate::dom::bindings::num::Finite;
 use crate::dom::bindings::reflector::{reflect_dom_object, DomObject, Reflector};
-use crate::dom::bindings::root::{DomRoot, MutNullableDom};
+use crate::dom::bindings::root::{Dom, DomRoot, MutNullableDom};
 use crate::dom::globalscope::GlobalScope;
+use crate::dom::xrlayer::XRLayer;
 use crate::dom::xrwebgllayer::XRWebGLLayer;
-
 use dom_struct::dom_struct;
 use std::cell::Cell;
+use webxr_api::SwapChainId;
 
 #[dom_struct]
 pub struct XRRenderState {
@@ -19,6 +22,42 @@ pub struct XRRenderState {
     depth_far: Cell<f64>,
     inline_vertical_fov: Cell<Option<f64>>,
     layer: MutNullableDom<XRWebGLLayer>,
+    layers: DomRefCell<Vec<XRWebGLLayerOrXRLayer>>,
+}
+
+#[unrooted_must_root_lint::must_root]
+#[derive(Clone, JSTraceable, MallocSizeOf)]
+pub enum XRWebGLLayerOrXRLayer {
+    XRWebGLLayer(Dom<XRWebGLLayer>),
+    XRLayer(Dom<XRLayer>),
+}
+
+impl XRWebGLLayerOrXRLayer {
+    #[allow(unrooted_must_root)]
+    fn from_ref(layer: &RootedXRWebGLLayerOrXRLayer) -> XRWebGLLayerOrXRLayer {
+        match layer {
+            RootedXRWebGLLayerOrXRLayer::XRWebGLLayer(ref layer) => {
+                XRWebGLLayerOrXRLayer::XRWebGLLayer(Dom::from_ref(layer))
+            },
+            RootedXRWebGLLayerOrXRLayer::XRLayer(ref layer) => {
+                XRWebGLLayerOrXRLayer::XRLayer(Dom::from_ref(layer))
+            },
+        }
+    }
+
+    pub fn swap_chain_id(&self) -> Option<SwapChainId> {
+        match self {
+            XRWebGLLayerOrXRLayer::XRWebGLLayer(layer) => Some(layer.swap_chain_id()),
+            XRWebGLLayerOrXRLayer::XRLayer(_) => None,
+        }
+    }
+
+    pub fn swap_buffers(&self) {
+        match self {
+            XRWebGLLayerOrXRLayer::XRWebGLLayer(layer) => layer.swap_buffers(),
+            XRWebGLLayerOrXRLayer::XRLayer(_) => (),
+        }
+    }
 }
 
 impl XRRenderState {
@@ -27,13 +66,16 @@ impl XRRenderState {
         depth_far: f64,
         inline_vertical_fov: Option<f64>,
         layer: Option<&XRWebGLLayer>,
+        layers: &[XRWebGLLayerOrXRLayer],
     ) -> XRRenderState {
+        debug_assert!(layer.is_none() || layers.is_empty());
         XRRenderState {
             reflector_: Reflector::new(),
             depth_near: Cell::new(depth_near),
             depth_far: Cell::new(depth_far),
             inline_vertical_fov: Cell::new(inline_vertical_fov),
             layer: MutNullableDom::new(layer),
+            layers: DomRefCell::new(layers.iter().cloned().collect()),
         }
     }
 
@@ -43,6 +85,7 @@ impl XRRenderState {
         depth_far: f64,
         inline_vertical_fov: Option<f64>,
         layer: Option<&XRWebGLLayer>,
+        layers: &[XRWebGLLayerOrXRLayer],
     ) -> DomRoot<XRRenderState> {
         reflect_dom_object(
             Box::new(XRRenderState::new_inherited(
@@ -50,18 +93,21 @@ impl XRRenderState {
                 depth_far,
                 inline_vertical_fov,
                 layer,
+                layers,
             )),
             global,
         )
     }
 
     pub fn clone_object(&self) -> DomRoot<Self> {
+        let layers = self.layers.borrow();
         XRRenderState::new(
             &self.global(),
             self.depth_near.get(),
             self.depth_far.get(),
             self.inline_vertical_fov.get(),
             self.layer.get().as_ref().map(|x| &**x),
+            &layers,
         )
     }
 
@@ -78,6 +124,19 @@ impl XRRenderState {
     pub fn set_layer(&self, layer: Option<&XRWebGLLayer>) {
         self.layer.set(layer)
     }
+    pub fn set_layers(&self, layers: &[RootedXRWebGLLayerOrXRLayer]) {
+        *self.layers.borrow_mut() = layers.iter().map(XRWebGLLayerOrXRLayer::from_ref).collect();
+    }
+    pub fn with_layers<F, R>(&self, f: F) -> R
+    where
+        F: FnOnce(&[XRWebGLLayerOrXRLayer]) -> R,
+    {
+        let layers = self.layers.borrow();
+        f(&*layers)
+    }
+    pub fn has_layer(&self) -> bool {
+        self.layer.get().is_some() || !self.layers.borrow().is_empty()
+    }
 }
 
 impl XRRenderStateMethods for XRRenderState {