add new XrSpace and impl that

Signed-off-by: Schmarni <marnistromer@gmail.com>

crates/bevy_xr/src/spaces.rs

@@ -0,0 +1,46 @@
+use bevy::{
+    prelude::*,
+    render::{extract_component::ExtractComponent, extract_resource::ExtractResource},
+};
+
+/// Any Spaces will be invalid after the owning session exits
+#[repr(transparent)]
+#[derive(Clone, Copy, Hash, PartialEq, Eq, Reflect, Debug)]
+pub struct XrSpace(u64);
+
+#[derive(Clone, Copy, PartialEq, Reflect, Debug, Component, ExtractComponent)]
+pub struct XrSpatialTransform {
+    pub space: XrSpace,
+    pub offset: Transform,
+}
+impl XrSpatialTransform {
+    pub const fn from_space(space: XrSpace) -> Self {
+        Self { space, offset: Transform::IDENTITY }
+    }
+}
+
+#[derive(Event, Clone, Copy, Deref, DerefMut)]
+pub struct XrDestroySpace(pub XrSpace);
+
+#[repr(transparent)]
+#[derive(
+    Clone, Copy, Hash, PartialEq, Eq, Reflect, Debug, Component, Deref, DerefMut, ExtractComponent,
+)]
+pub struct XrReferenceSpace(pub XrSpace);
+
+#[repr(transparent)]
+#[derive(
+    Clone, Copy, Hash, PartialEq, Eq, Reflect, Debug, Resource, Deref, DerefMut, ExtractResource,
+)]
+pub struct XrPrimaryReferenceSpace(pub XrReferenceSpace);
+
+impl XrSpace {
+    /// # Safety
+    /// only call with known valid handles
+    pub unsafe fn from_raw(handle: u64) -> Self {
+        Self(handle)
+    }
+    pub fn as_raw(&self) -> u64 {
+        self.0
+    }
+}