Added first-cut implementation of XR layers

components/script/dom/xrwebglsubimage.rs

@@ -0,0 +1,35 @@
+/* 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::XRWebGLSubImageBinding::XRWebGLSubImageBinding::XRWebGLSubImageMethods;
+use crate::dom::bindings::root::Dom;
+use crate::dom::bindings::root::DomRoot;
+use crate::dom::webgltexture::WebGLTexture;
+use crate::dom::xrsubimage::XRSubImage;
+use dom_struct::dom_struct;
+
+#[dom_struct]
+pub struct XRWebGLSubImage {
+    xr_sub_image: XRSubImage,
+    color_texture: Dom<WebGLTexture>,
+    depth_stencil_texture: Option<Dom<WebGLTexture>>,
+    image_index: Option<u32>,
+}
+
+impl XRWebGLSubImageMethods for XRWebGLSubImage {
+    /// https://immersive-web.github.io/layers/#dom-xrwebglsubimage-colortexture
+    fn ColorTexture(&self) -> DomRoot<WebGLTexture> {
+        DomRoot::from_ref(&self.color_texture)
+    }
+
+    /// https://immersive-web.github.io/layers/#dom-xrwebglsubimage-depthstenciltexture
+    fn GetDepthStencilTexture(&self) -> Option<DomRoot<WebGLTexture>> {
+        self.depth_stencil_texture.as_deref().map(DomRoot::from_ref)
+    }
+
+    /// https://immersive-web.github.io/layers/#dom-xrwebglsubimage-imageindex
+    fn GetImageIndex(&self) -> Option<u32> {
+        self.image_index
+    }
+}