1 files changed, 155 insertions, 0 deletions
diff --git a/components/script/dom/webxr/xrrenderstate.rs b/components/script/dom/webxr/xrrenderstate.rs
new file mode 100644
index 00000000000..cf6976404d6
--- /dev/null
+++ b/components/script/dom/webxr/xrrenderstate.rs
@@ -0,0 +1,155 @@
+/* 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 std::cell::Cell;
+
+use dom_struct::dom_struct;
+use js::rust::MutableHandleValue;
+use webxr_api::SubImages;
+
+use crate::dom::bindings::cell::DomRefCell;
+use crate::dom::bindings::codegen::Bindings::XRRenderStateBinding::XRRenderStateMethods;
+use crate::dom::bindings::num::Finite;
+use crate::dom::bindings::reflector::{reflect_dom_object, DomObject, Reflector};
+use crate::dom::bindings::root::{Dom, DomRoot, MutNullableDom};
+use crate::dom::bindings::utils::to_frozen_array;
+use crate::dom::globalscope::GlobalScope;
+use crate::dom::xrlayer::XRLayer;
+use crate::dom::xrwebgllayer::XRWebGLLayer;
+use crate::script_runtime::JSContext;
+
+#[dom_struct]
+pub struct XRRenderState {
+    reflector_: Reflector,
+    depth_near: Cell<f64>,
+    depth_far: Cell<f64>,
+    inline_vertical_fov: Cell<Option<f64>>,
+    base_layer: MutNullableDom<XRWebGLLayer>,
+    layers: DomRefCell<Vec<Dom<XRLayer>>>,
+}
+
+impl XRRenderState {
+    pub fn new_inherited(
+        depth_near: f64,
+        depth_far: f64,
+        inline_vertical_fov: Option<f64>,
+        layer: Option<&XRWebGLLayer>,
+        layers: Vec<&XRLayer>,
+    ) -> 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),
+            base_layer: MutNullableDom::new(layer),
+            layers: DomRefCell::new(layers.into_iter().map(Dom::from_ref).collect()),
+        }
+    }
+
+    pub fn new(
+        global: &GlobalScope,
+        depth_near: f64,
+        depth_far: f64,
+        inline_vertical_fov: Option<f64>,
+        layer: Option<&XRWebGLLayer>,
+        layers: Vec<&XRLayer>,
+    ) -> DomRoot<XRRenderState> {
+        reflect_dom_object(
+            Box::new(XRRenderState::new_inherited(
+                depth_near,
+                depth_far,
+                inline_vertical_fov,
+                layer,
+                layers,
+            )),
+            global,
+        )
+    }
+
+    pub fn clone_object(&self) -> DomRoot<Self> {
+        XRRenderState::new(
+            &self.global(),
+            self.depth_near.get(),
+            self.depth_far.get(),
+            self.inline_vertical_fov.get(),
+            self.base_layer.get().as_deref(),
+            self.layers.borrow().iter().map(|x| &**x).collect(),
+        )
+    }
+
+    pub fn set_depth_near(&self, depth: f64) {
+        self.depth_near.set(depth)
+    }
+    pub fn set_depth_far(&self, depth: f64) {
+        self.depth_far.set(depth)
+    }
+    pub fn set_inline_vertical_fov(&self, fov: f64) {
+        debug_assert!(self.inline_vertical_fov.get().is_some());
+        self.inline_vertical_fov.set(Some(fov))
+    }
+    pub fn set_base_layer(&self, layer: Option<&XRWebGLLayer>) {
+        self.base_layer.set(layer)
+    }
+    pub fn set_layers(&self, layers: Vec<&XRLayer>) {
+        *self.layers.borrow_mut() = layers.into_iter().map(Dom::from_ref).collect();
+    }
+    pub fn with_layers<F, R>(&self, f: F) -> R
+    where
+        F: FnOnce(&[Dom<XRLayer>]) -> R,
+    {
+        let layers = self.layers.borrow();
+        f(&layers)
+    }
+    pub fn has_sub_images(&self, sub_images: &[SubImages]) -> bool {
+        if let Some(base_layer) = self.base_layer.get() {
+            match sub_images.len() {
+                // For inline sessions, there may be a base layer, but it won't have a framebuffer
+                0 => base_layer.layer_id().is_none(),
+                // For immersive sessions, the base layer will have a framebuffer,
+                // so we make sure the layer id's match up
+                1 => base_layer.layer_id() == Some(sub_images[0].layer_id),
+                _ => false,
+            }
+        } else {
+            // The layers API is only for immersive sessions
+            let layers = self.layers.borrow();
+            sub_images.len() == layers.len() &&
+                sub_images
+                    .iter()
+                    .zip(layers.iter())
+                    .all(|(sub_image, layer)| Some(sub_image.layer_id) == layer.layer_id())
+        }
+    }
+}
+
+impl XRRenderStateMethods<crate::DomTypeHolder> for XRRenderState {
+    /// <https://immersive-web.github.io/webxr/#dom-xrrenderstate-depthnear>
+    fn DepthNear(&self) -> Finite<f64> {
+        Finite::wrap(self.depth_near.get())
+    }
+
+    /// <https://immersive-web.github.io/webxr/#dom-xrrenderstate-depthfar>
+    fn DepthFar(&self) -> Finite<f64> {
+        Finite::wrap(self.depth_far.get())
+    }
+
+    /// <https://immersive-web.github.io/webxr/#dom-xrrenderstate-inlineverticalfieldofview>
+    fn GetInlineVerticalFieldOfView(&self) -> Option<Finite<f64>> {
+        self.inline_vertical_fov.get().map(Finite::wrap)
+    }
+
+    /// <https://immersive-web.github.io/webxr/#dom-xrrenderstate-baselayer>
+    fn GetBaseLayer(&self) -> Option<DomRoot<XRWebGLLayer>> {
+        self.base_layer.get()
+    }
+
+    /// <https://immersive-web.github.io/layers/#dom-xrrenderstate-layers>
+    fn Layers(&self, cx: JSContext, retval: MutableHandleValue) {
+        // TODO: cache this array?
+        let layers = self.layers.borrow();
+        let layers: Vec<&XRLayer> = layers.iter().map(|x| &**x).collect();
+        to_frozen_array(&layers[..], cx, retval)
+    }
+}