Add config file resource for hand tracking/slimevr skeleton ratios.

Author: Sebane1

driver/slimevr/resources/slimevr_driver_config.json

@@ -0,0 +1,6 @@
+{
+  "external_hand_max_radius_m": 1.7,
+  "stale_external_pose_frames": 1,
+  "pose_lerp_speed": 0.8,
+  "frozen_pose_position_epsilon_m": 0.005
+}

src/IVRDriver.hpp

@@ -97,6 +97,9 @@ class IVRDriver : protected vr::IServerTrackedDeviceProvider {
   virtual std::optional<vr::DriverPose_t>
   GetExternalPoseForHand(bool left_hand) = 0;
 
+  /** Pose lerp speed (0–1) for smoothing VD/SlimeVR transitions. From driver config file. */
+  virtual float GetPoseLerpSpeed() = 0;
+
   virtual inline const char *const *GetInterfaceVersions() override {
     return vr::k_InterfaceVersions;
   };

src/TrackerDevice.cpp

@@ -152,7 +152,7 @@ void SlimeVRDriver::TrackerDevice::Update() {
   if (!smoothed_pose_.has_value())
     smoothed_pose_ = target;
   else
-    smoothed_pose_ = LerpPose(*smoothed_pose_, target, kPoseLerpSpeed);
+    smoothed_pose_ = LerpPose(*smoothed_pose_, target, GetDriver()->GetPoseLerpSpeed());
   GetDriver()->GetDriverHost()->TrackedDevicePoseUpdated(
       device_index_, *smoothed_pose_, sizeof(vr::DriverPose_t));
 }

src/TrackerDevice.hpp

@@ -70,7 +70,6 @@ class TrackerDevice : public IVRDevice {
   std::atomic<vr::DriverPose_t> last_pose_atomic_ =
       IVRDevice::MakeDefaultPose();
   std::optional<vr::DriverPose_t> smoothed_pose_;
-  static constexpr float kPoseLerpSpeed = 0.8f;
   static vr::DriverPose_t LerpPose(const vr::DriverPose_t &from,
                                    const vr::DriverPose_t &to, float t);
 

src/VRDriver.cpp

@@ -32,6 +32,8 @@ SlimeVRDriver::VRDriver::Init(vr::IVRDriverContext *pDriverContext) {
 
   logger_->Log("SlimeVR Driver Loaded Successfully");
 
+  LoadDriverConfig();
+
   bridge_ = std::make_shared<BridgeClient>(
       std::static_pointer_cast<Logger>(std::make_shared<VRLogger>("Bridge")),
       std::bind(&SlimeVRDriver::VRDriver::OnBridgeMessage, this,
@@ -349,6 +351,32 @@ bool SlimeVRDriver::VRDriver::AddDevice(std::shared_ptr<IVRDevice> device) {
   return true;
 }
 
+void SlimeVRDriver::VRDriver::LoadDriverConfig() {
+  vr::IVRResources *res = vr::VRResources();
+  if (!res) return;
+  char path[1024];
+  uint32_t len = res->GetResourceFullPath(
+      "slimevr_driver_config.json", "", path, sizeof(path));
+  if (len == 0 || len >= sizeof(path)) return;
+  path[len] = '\0';
+  try {
+    auto json = simdjson::padded_string::load(path);
+    simdjson::ondemand::document doc = json_parser_.iterate(json);
+    auto obj = doc.get_object();
+    if (auto v = obj["external_hand_max_radius_m"]; !v.error()) config_external_hand_max_radius_m_ = static_cast<float>(v.get_double());
+    if (auto v = obj["stale_external_pose_frames"]; !v.error()) config_stale_external_pose_frames_ = static_cast<int>(v.get_int64());
+    if (auto v = obj["pose_lerp_speed"]; !v.error()) config_pose_lerp_speed_ = static_cast<float>(v.get_double());
+    if (auto v = obj["frozen_pose_position_epsilon_m"]; !v.error()) config_frozen_pose_position_epsilon_m_ = static_cast<float>(v.get_double());
+    logger_->Log("Loaded driver config from {}", path);
+  } catch (const simdjson::simdjson_error &) {
+    // Use defaults; config file missing or invalid
+  }
+}
+
+float SlimeVRDriver::VRDriver::GetPoseLerpSpeed() {
+  return config_pose_lerp_speed_;
+}
+
 SlimeVRDriver::SettingsValue
 SlimeVRDriver::VRDriver::GetSettingsValue(std::string key) {
   vr::EVRSettingsError err = vr::EVRSettingsError::VRSettingsError_None;
@@ -555,9 +583,8 @@ vr::DriverPose_t SlimeVRDriver::VRDriver::DriverPoseFromTrackedDevicePose(
 }
 
 bool SlimeVRDriver::VRDriver::ExternalPoseEquals(const vr::DriverPose_t &a,
-                                                 const vr::DriverPose_t &b) {
-  // Position only; rotation ignored so small rotation jitter doesn't block frozen detection.
-  const float pos_eps = 0.005f; // ~5 mm
+                                                 const vr::DriverPose_t &b) const {
+  float pos_eps = config_frozen_pose_position_epsilon_m_;
   for (int i = 0; i < 3; i++) {
     if (std::fabs(a.vecPosition[i] - b.vecPosition[i]) > pos_eps)
       return false;
@@ -566,14 +593,15 @@ bool SlimeVRDriver::VRDriver::ExternalPoseEquals(const vr::DriverPose_t &a,
 }
 
 bool SlimeVRDriver::VRDriver::ExternalHandInFrontAndInRadius(
-    const double hand_pos[3], const vr::TrackedDevicePose_t &hmd_pose) {
+    const double hand_pos[3], const vr::TrackedDevicePose_t &hmd_pose) const {
   if (!hmd_pose.bPoseIsValid)
     return false;
+  double r = static_cast<double>(config_external_hand_max_radius_m_);
   const auto &m = hmd_pose.mDeviceToAbsoluteTracking.m;
   double hx = m[0][3], hy = m[1][3], hz = m[2][3];
   double dx = hand_pos[0] - hx, dy = hand_pos[1] - hy, dz = hand_pos[2] - hz;
   double dist_sq = dx * dx + dy * dy + dz * dz;
-  if (dist_sq > static_cast<double>(kExternalHandMaxRadius) * kExternalHandMaxRadius)
+  if (dist_sq > r * r)
     return false;
   // Forward = -Z in OpenVR (third column of rotation)
   double fx = -m[0][2], fy = -m[1][2], fz = -m[2][2];
@@ -640,7 +668,7 @@ void SlimeVRDriver::VRDriver::UpdateExternalControllerPoses() {
       if (last_external_left_pose_.has_value() &&
           ExternalPoseEquals(driver_pose, *last_external_left_pose_)) {
         stale_external_left_frames_++;
-        if (stale_external_left_frames_ >= kStaleExternalPoseFrames)
+        if (stale_external_left_frames_ >= config_stale_external_pose_frames_)
           external_left_pose_ = std::nullopt; // swap to SlimeVR
         else
           external_left_pose_ = driver_pose;
@@ -653,7 +681,7 @@ void SlimeVRDriver::VRDriver::UpdateExternalControllerPoses() {
       if (last_external_right_pose_.has_value() &&
           ExternalPoseEquals(driver_pose, *last_external_right_pose_)) {
         stale_external_right_frames_++;
-        if (stale_external_right_frames_ >= kStaleExternalPoseFrames)
+        if (stale_external_right_frames_ >= config_stale_external_pose_frames_)
           external_right_pose_ = std::nullopt; // swap to SlimeVR
         else
           external_right_pose_ = driver_pose;

src/VRDriver.hpp

@@ -87,17 +87,19 @@ class VRDriver : public IVRDriver {
   std::optional<vr::DriverPose_t> last_external_right_pose_;
   int stale_external_left_frames_ = 0;
   int stale_external_right_frames_ = 0;
-  static constexpr int kStaleExternalPoseFrames = 1;
-  /// Max distance (meters) from HMD for using external hand; beyond this or behind HMD → SlimeVR. 1.7f = 170 cm.
-  static constexpr float kExternalHandMaxRadius = 1.7f;
+  // Values from slimevr_driver_config.json (fallbacks if file missing)
+  float config_external_hand_max_radius_m_ = 1.7f;
+  int config_stale_external_pose_frames_ = 1;
+  float config_pose_lerp_speed_ = 0.8f;
+  float config_frozen_pose_position_epsilon_m_ = 0.005f;
+  void LoadDriverConfig();
   void UpdateExternalControllerPoses();
   static vr::DriverPose_t
   DriverPoseFromTrackedDevicePose(const vr::TrackedDevicePose_t &raw);
-  static bool ExternalPoseEquals(const vr::DriverPose_t &a,
-                                 const vr::DriverPose_t &b);
-  /// True if hand position is in front of HMD and within kExternalHandMaxRadius.
-  static bool
-  ExternalHandInFrontAndInRadius(const double hand_pos[3],
-                                 const vr::TrackedDevicePose_t &hmd_pose);
+  bool ExternalPoseEquals(const vr::DriverPose_t &a,
+                          const vr::DriverPose_t &b) const;
+  bool ExternalHandInFrontAndInRadius(const double hand_pos[3],
+                                     const vr::TrackedDevicePose_t &hmd_pose) const;
+  virtual float GetPoseLerpSpeed() override;
 };
 }; // namespace SlimeVRDriver