FilterInput(ref inputTrackingState);

/**
 * Selects how controller tracking is filtered.
 * You can specify the mimimum distance between hands and head,
 * and what to do about distant or inactive controllers.
 * Subclasses can override to change clamp/disable distances, or simply skip
 * this filtering.
 * @param inputState    which controllers to affect.
 * @param inputTransforms has the current controller position & orientation on
 * entry, gets the updated position & orientation on exit.
 * @see CAPI.ovrAvatar2InputState
 * @see CAPI.ovrAvatar2InputTransforms
 */
protected virtual void FilterInput(ref OvrAvatarInputTrackingState inputTracking) {
  ClampHandPositions(ref inputTracking, out var handDistances, DEFAULT_CLAMP_DIST_SQUARED);
  DisableDistantControllers(ref inputTracking, in handDistances, DEFAULT_DISABLE_DIST_SQUARED);
  HideInactiveControllers(ref inputTracking);
}

/**
 * Clamp hand distance from head to be within a specified distance.
 * @param tracking             input position & orientation of each controller.
 * @param distances            gets the squared distance of each hand on output.
 * @param clampDistanceSquared maximum distance between hands and head squared.
 * @see FilterInput
 * @see CAPI.ovrAvatar2InputTransforms
 * @see InputHandDistances
 */
protected static void ClampHandPositions(ref OvrAvatarInputTrackingState tracking, out InputHandDistances distances, float clampDistanceSquared) {
  ref readonly var hmdPos = ref tracking.headset.position;
  ref var leftHandPos = ref tracking.leftController.position;
  ref var rightHandPos = ref tracking.rightController.position;

  var leftHandDist = ClampHand(in hmdPos, ref leftHandPos, clampDistanceSquared);
  var rightHandDist = ClampHand(in hmdPos, ref rightHandPos, clampDistanceSquared);

  distances = new InputHandDistances(leftHandDist, rightHandDist);
}

/**
 * Disable controllers further than the specified distance.
 * @param inputControl           which controllers to affect.
 * @param handDistances          squared distance of controller.
 * @param disableDistanceSquared distance beyond which controller is disabled
 * squared.
 * @see FilterInput
 * @see CAPI.ovrAvatar2InputState
 * @see InputHandDistances
 */
protected static void DisableDistantControllers(ref OvrAvatarInputTrackingState inputTracking, in InputHandDistances handDistances, float disableDistanceSquared) {
  DisableDistantController(ref inputTracking.leftControllerActive, handDistances.leftSquared, disableDistanceSquared);
  DisableDistantController(ref inputTracking.rightControllerActive, handDistances.rightSquared, disableDistanceSquared);
}

/**
 * Hide rendering of inactive controllers.
 * @param inputControl   which controllers to affect.
 * @see FilterInput
 * @see CAPI.ovrAvatar2InputState
 */
protected static void HideInactiveControllers(ref OvrAvatarInputTrackingState inputTracking) {
  inputTracking.leftControllerVisible &= inputTracking.leftControllerActive;
  inputTracking.rightControllerVisible &= inputTracking.rightControllerActive;
}