Refactor stereo frame worker and interpolation tests for enhanced VR performance

- Updated stereo_frame_worker_smoke.cpp to allow dynamic headset rates and prediction lead time.
- Improved logging to include motion diagnostics and adjusted frame submission logic based on headset frequency.
- Enhanced stereo_interpolation_test.cpp with additional tests for camera motion separation and playback cadence.
- Introduced MkwVRReadSceneView function to read the camera view matrix for improved scene rendering.
- Modified VR first-person logic to support scene view reading and validation.
- Added scene_camera.hpp to encapsulate camera motion handling and inverse view calculations.
- Ensured that the VR integration layer correctly logs motion diagnostics and handles scene playback accurately.

runtime/include/vr/mkw_vr_first_person.h

@@ -573,6 +573,10 @@ void MkwVRFirstPersonRecenter() noexcept;
 // anchor has been missing long enough to give up holding the last one.
 FirstPersonAnchor MkwVRFirstPersonGetAnchor() noexcept;
 
+// Checked guest-thread read of the camera that authored this frame's GX draws.
+// Also available with first person off; render workers receive only its copy.
+bool MkwVRReadSceneView(Mtx34& view) noexcept;
+
 // Guest-frame inventory snapshot, sampled at the race draw boundary. A
 // generation change invalidates any item retained by a prior race.
 HeldItem MkwVRFirstPersonGetHeldItem() noexcept;

runtime/src/hle/vi.cpp

@@ -37,6 +37,7 @@
 #endif
 
 #include <aurora/aurora.h>
+#include <aurora/gfx.h>
 
 // Forward declaration for OSWakeupThread - used to wake threads on VI retrace queue
 extern "C" void OSWakeupThread_HLE_801aaaa4(CpuContext* ctx);
@@ -538,6 +539,8 @@ void PaceToRetraceBoundary(Clock::time_point deadline) {
 struct SceneAnchorPublication {
     std::array<float, 12> anchor{};
     bool valid = false;
+    std::array<float, 12> view{};
+    bool viewValid = false;
     // The cockpit seat's exact world scale for this frame, or zero.
     float unitsPerMeter = 0.0f;
 };
@@ -550,6 +553,8 @@ SceneAnchorPublication PublishVrSceneAnchor() {
     mkw::vr::MkwVRFirstPersonCommit();
     const mkw::vr::FirstPersonAnchor anchor = mkw::vr::MkwVRFirstPersonGetAnchor();
     SceneAnchorPublication publication;
+    // Only VR frame interpolation separates the camera, so nothing else pays for the read.
+    publication.viewValid = aurora_get_stereo_frame_interpolation() && mkw::vr::MkwVRReadSceneView(publication.view);
     publication.valid = anchor.valid;
     if (anchor.valid) {
         std::copy(anchor.anchor_from_scene.begin(), anchor.anchor_from_scene.end(), publication.anchor.begin());
@@ -592,6 +597,8 @@ struct GxPresentRecord {
     uint64_t scheduleIntervalNanos = 0;
     std::array<float, 12> anchor{};
     bool anchorValid = false;
+    std::array<float, 12> view{};
+    bool viewValid = false;
     float anchorUnitsPerMeter = 0.0f;
     AuroraCockpitItem cockpitItem{};
     bool reportPaced = false;
@@ -613,6 +620,7 @@ void GxPresent_gx(GxPresentRecord record) {
     }
     aurora_set_stereo_cockpit_item(&record.cockpitItem);
     aurora_set_stereo_local_player_count(record.localPlayerCount);
+    aurora_set_stereo_scene_view(record.viewValid ? record.view.data() : nullptr);
     aurora_end_frame_ex(record.contentTag, record.imguiFrame);
     g_auroraFrameActive.store(false, std::memory_order_release);
     g_auroraFrameHadWork.store(false, std::memory_order_release);
@@ -695,6 +703,8 @@ void VI_HLE_PresentFrame(bool presentedXfb, bool paceToRetrace) {
     const SceneAnchorPublication anchor = PublishVrSceneAnchor();
     record.anchor = anchor.anchor;
     record.anchorValid = anchor.valid;
+    record.view = anchor.view;
+    record.viewValid = anchor.viewValid;
     record.anchorUnitsPerMeter = anchor.unitsPerMeter;
     if (anchor.valid) {
         const auto item = mkw::vr::MkwVRFirstPersonGetHeldItem();

runtime/src/vr/mkw_vr_first_person.cpp

@@ -1422,6 +1422,10 @@ void MkwVRFirstPersonRecenter() noexcept {
     g_recenter_requested.store(true, std::memory_order_release);
 }
 
+bool MkwVRReadSceneView(Mtx34& view) noexcept {
+    return ReadSceneViewMatrix(view);
+}
+
 void MkwVRFirstPersonUpdate(uint64_t guest_frame_index, uint32_t race_camera_address) noexcept {
     std::lock_guard lock(g_mutex);
     g_state.held_item = {};

runtime/src/vr/openxr_integration.cpp

@@ -893,6 +893,7 @@ private:
             }
 
             const MkwVRPolicySnapshot policy = MkwVRPolicyGetSnapshot();
+            aurora_set_stereo_motion_logging(diagnostics::Enabled());
             // Diagnostics lift the cap: a presentation flickering between the
             // race and the virtual screen is exactly what a report needs to show.
             if ((!presentation_logged || policy.presentation != logged_presentation) &&