private void Correct(IClock fixedClock)
{
if (_serverHistory.Count < 1)
{
Debug.Log("no server history available");
return;
}
/* Extrapolate last received server state to catch up to client time */
/* Todo: Save massive amounts of calculation by only simulating 1 correction tick per actual physics frame, you dummy
* New server state? Do offline sim for however many steps it requires to catch up to local client time instantly.
* THEN, then you only have to simulate one tick for each real-time physics tick in order to keep up. Until the new server state arrives.
*
* So in this method we only tick once
* In the receive state handler we tick multiple times to catch up to local client time
*/
var latency = _lastReceivedStateRTT / 2d;
var timeSinceLastReceivedState = fixedClock.CurrentTime - _lastReceivedStateTimestamp;
var timeSinceServerState = latency + timeSinceLastReceivedState;
var startTime = _lastReceivedStateTimestamp - latency;
Debug.Assert(timeSinceServerState > 0.0, "timeSinceServerState > 0: " + timeSinceServerState);
_eulerBody.State = _lastServerState;
PlayerSimulation.SimulateOffline(_simulation.Config, _eulerBody, t => _inputHistory.Lerp(t), startTime, timeSinceServerState, fixedClock.DeltaTime);
_correctedState = _eulerBody.State;
/* Calculate error between corrected server state and current client state */
var currentClientState = _simulation.UnityBody.State;
const float maxPosError = 2f;
const float maxRotError = 45f;
_posError = Vector3.Distance(currentClientState.Position, _correctedState.Position) / maxPosError;
_rotError = Quaternion.Angle(currentClientState.Rotation, _correctedState.Rotation) / maxRotError;
/* Apply corrected state over time, with use of error metrics */
_posErrorSmooth = Mathf.Lerp(_posErrorSmooth, 0.5f + _posError, 1f / _errorSmoothing * fixedClock.DeltaTime);
_rotErrorSmooth = Mathf.Lerp(_rotErrorSmooth, 0.5f + _rotError, 1f / _errorSmoothing * fixedClock.DeltaTime);
var interpolatedState = RigidbodyExtensions.Lerp(
currentClientState, _correctedState,
_posErrorSmooth * fixedClock.DeltaTime * _errorCorrectionSpeed,
_rotErrorSmooth * fixedClock.DeltaTime * _errorCorrectionSpeed);
if (_applyCorrection)
{
interpolatedState.ApplyTo(_simulation.UnityBody.Rigidbody);
}
}
