small changes

xr_api/src/api_traits.rs

@@ -1,4 +1,4 @@
-use glam::{UVec2, Vec2};
+use glam::{UVec2, Vec2, Vec3A};
 use wgpu::{Adapter, AdapterInfo, Device, Queue, TextureView};
 
 use crate::prelude::*;
@@ -27,10 +27,14 @@ pub trait SessionTrait {
     /// Get render resources compatible with this session.
     fn get_render_resources(&self)
         -> Option<(Device, Queue, AdapterInfo, Adapter, wgpu::Instance)>;
+    /// Returns the position of the headset.
+    fn headset_location(&self) -> Result<Pose>;
     /// Request input modules with the specified bindings.
     fn create_input(&self, bindings: Bindings) -> Result<Input>;
     /// Blocks until a rendering frame is available, then returns the views for the left and right eyes.
-    fn begin_frame(&self) -> Result<(View, View)>;
+    fn begin_frame(&self) -> Result<()>;
+    /// Locate the views of each eye.
+    fn locate_views(&self) -> Result<(View, View)>;
     /// Submits rendering work for this frame.
     fn end_frame(&self) -> Result<()>;
     /// Gets the resolution of a single eye.
@@ -45,7 +49,9 @@ pub trait ViewTrait {
     /// Returns the [Pose] representing the current position of this view.
     fn pose(&self) -> Pose;
     /// Returns the projection matrix for the current view.
-    fn projection_matrix(&self) -> glam::Mat4;
+    fn projection_matrix(&self, near: f32, far: f32) -> glam::Mat4;
+    /// Gets the fov of the camera.
+    fn fov(&self) -> Fov;
     /// Gets the resolution for this view.
     fn resolution(&self) -> UVec2;
     /// Gets the texture format for the view.

xr_api/src/backend/oxr.rs

@@ -1,9 +1,11 @@
 mod graphics;
 mod utils;
 
+use utils::UntypedOXrAction;
+
 use std::{marker::PhantomData, rc::Rc, sync::Mutex};
 
-use glam::{Mat4, UVec2, Vec2};
+use glam::{Mat4, UVec2, Vec2, Vec3A};
 use hashbrown::{hash_map, HashMap};
 use openxr::{EnvironmentBlendMode, Vector2f};
 use tracing::{info, info_span, warn};
@@ -71,14 +73,6 @@ impl InstanceTrait for OXrInstance {
     }
 }
 
-pub(crate) enum UntypedOXrAction {
-    Haptics(openxr::Action<openxr::Haptic>),
-    Pose(openxr::Action<openxr::Posef>),
-    Float(openxr::Action<f32>),
-    Bool(openxr::Action<bool>),
-    Vec2(openxr::Action<openxr::Vector2f>),
-}
-
 #[derive(Default)]
 pub(crate) struct BindingState {
     sessions_attached: bool,
@@ -151,7 +145,7 @@ impl SessionTrait for OXrSession {
         .into())
     }
 
-    fn begin_frame(&self) -> Result<(View, View)> {
+    fn begin_frame(&self) -> Result<()> {
         {
             let mut bindings = self.bindings.lock().unwrap();
             if !bindings.sessions_attached {
@@ -263,6 +257,10 @@ impl SessionTrait for OXrSession {
             self.session
                 .sync_actions(&action_sets.iter().map(Into::into).collect::<Vec<_>>())?;
         }
+        Ok(())
+    }
+
+    fn locate_views(&self) -> Result<(View, View)> {
         let views = {
             let _span = info_span!("xr_locate_views").entered();
             self.session
@@ -326,6 +324,14 @@ impl SessionTrait for OXrSession {
     fn format(&self) -> wgpu::TextureFormat {
         self.format
     }
+
+    fn headset_location(&self) -> Result<Pose> {
+        let location = self.head.locate(
+            &self.stage,
+            self.frame_state.lock().unwrap().predicted_display_time,
+        )?;
+        Ok(location.pose.into())
+    }
 }
 
 pub struct OXrInput {
@@ -498,7 +504,7 @@ impl ViewTrait for OXrView {
         self.view.pose.clone().into()
     }
 
-    fn projection_matrix(&self) -> glam::Mat4 {
+    fn projection_matrix(&self, near: f32, far: f32) -> glam::Mat4 {
         //  symmetric perspective for debugging
         // let x_fov = (self.fov.angle_left.abs() + self.fov.angle_right.abs());
         // let y_fov = (self.fov.angle_up.abs() + self.fov.angle_down.abs());
@@ -506,9 +512,6 @@ impl ViewTrait for OXrView {
 
         let fov = self.view.fov;
         let is_vulkan_api = false; // FIXME wgpu probably abstracts this
-        let near_z = 0.1;
-        let far_z = -1.; //   use infinite proj
-                         // let far_z = self.far;
 
         let tan_angle_left = fov.angle_left.tan();
         let tan_angle_right = fov.angle_right.tan();
@@ -538,7 +541,7 @@ impl ViewTrait for OXrView {
 
         let mut cols: [f32; 16] = [0.0; 16];
 
-        if far_z <= near_z {
+        if far <= near {
             // place the far plane at infinity
             cols[0] = 2. / tan_angle_width;
             cols[4] = 0.;
@@ -553,7 +556,7 @@ impl ViewTrait for OXrView {
             cols[2] = 0.;
             cols[6] = 0.;
             cols[10] = -1.;
-            cols[14] = -(near_z + offset_z);
+            cols[14] = -(near + offset_z);
 
             cols[3] = 0.;
             cols[7] = 0.;
@@ -584,8 +587,8 @@ impl ViewTrait for OXrView {
 
             cols[2] = 0.;
             cols[6] = 0.;
-            cols[10] = -(far_z + offset_z) / (far_z - near_z);
-            cols[14] = -(far_z * (near_z + offset_z)) / (far_z - near_z);
+            cols[10] = -(far + offset_z) / (far - near);
+            cols[14] = -(far * (near + offset_z)) / (far - near);
 
             cols[3] = 0.;
             cols[7] = 0.;
@@ -603,4 +606,8 @@ impl ViewTrait for OXrView {
     fn format(&self) -> wgpu::TextureFormat {
         self.format
     }
+
+    fn fov(&self) -> Fov {
+        self.view.fov.into()
+    }
 }

xr_api/src/backend/oxr/utils.rs

@@ -1,5 +1,5 @@
 use glam::Quat;
-use openxr::Posef;
+use openxr::{Action, Fovf, Posef};
 
 use crate::{
     error::XrError,
@@ -7,7 +7,7 @@ use crate::{
     prelude::Pose,
 };
 
-use super::Bindings;
+use super::{Bindings, Fov};
 
 impl From<openxr::sys::Result> for XrError {
     fn from(_: openxr::sys::Result) -> Self {
@@ -20,9 +20,9 @@ impl From<Posef> for Pose {
         // with enough sign errors anything is possible
         let rotation = {
             let o = pose.orientation;
-            Quat::from_rotation_x(180.0f32.to_radians()) * glam::quat(o.w, o.z, o.y, o.x)
+            Quat::from_xyzw(o.x, o.y, o.z, o.w)
         };
-        let translation = glam::vec3(-pose.position.x, pose.position.y, -pose.position.z);
+        let translation = glam::vec3(pose.position.x, pose.position.y, pose.position.z);
 
         Pose {
             translation,
@@ -31,6 +31,69 @@ impl From<Posef> for Pose {
     }
 }
 
+impl From<Fovf> for Fov {
+    fn from(fov: Fovf) -> Self {
+        let Fovf {
+            angle_left,
+            angle_right,
+            angle_down,
+            angle_up,
+        } = fov;
+        Self {
+            angle_down,
+            angle_left,
+            angle_right,
+            angle_up,
+        }
+    }
+}
+
+macro_rules! untyped_oxr_actions {
+    (
+        $id:ident {
+            $(
+                $inner:ident($inner_ty:ty)
+            ),*
+            $(,)?
+        }
+    ) => {
+        pub(crate) enum $id {
+            $(
+                $inner($inner_ty),
+            )*
+        }
+
+        $(
+            impl TryInto<$inner_ty> for $id {
+                type Error = ();
+
+                fn try_into(self) -> std::prelude::v1::Result<$inner_ty, Self::Error> {
+                    match self {
+                        Self::$inner(action) => Ok(action),
+                        _ => Err(()),
+                    }
+                }
+            }
+
+            impl From<$inner_ty> for $id {
+                fn from(value: $inner_ty) -> Self {
+                    Self::$inner(value)
+                }
+            }
+        )*
+    };
+}
+
+untyped_oxr_actions! {
+    UntypedOXrAction {
+        Haptics(Action<openxr::Haptic>),
+        Pose(Action<openxr::Posef>),
+        Float(Action<f32>),
+        Bool(Action<bool>),
+        Vec2(Action<openxr::Vector2f>),
+    }
+}
+
 impl UntypedActionPath {
     pub(crate) fn into_xr_path(self) -> String {
         let dev_path;

xr_api/src/types.rs

@@ -22,11 +22,20 @@ pub enum Bindings {
 
 pub struct Haptic;
 
+#[derive(Clone, Copy, Debug, Default)]
 pub struct Pose {
     pub translation: Vec3,
     pub rotation: Quat,
 }
 
+#[derive(Clone, Copy, Debug, Default)]
+pub struct Fov {
+    pub angle_left: f32,
+    pub angle_right: f32,
+    pub angle_down: f32,
+    pub angle_up: f32,
+}
+
 pub trait ActionType: Sized {
     type Inner: ?Sized;