sync

make systems more stable by:
- fix wobbly, by doing CompSync and TimeSync in same ecs system
- dont interpolate on voxygen
- sync PhysState to the client in order to get rid of the jump snap to ground bug
- make the simulate_ahead more constant over time, as "jumps" in this number will be noticed by the client as "lag jumps"

There are still some problems
- [ ] Snap to the ground on jump isn't fixed completly, as we depend on tick n-1 and we only sync tick n to the client
- [ ] Arrows dont work properly yet with this commit, e.g. right click arrow attack
- [ ] Verify that clientcommands are actually broadcasted to all clients
- [ ] Followup: Agent needs to send clientcommands rather than commands

client/src/lib.rs

@@ -4,6 +4,7 @@
 
 pub mod addr;
 pub mod error;
+mod revertclock;
 
 // Reexports
 pub use crate::error::Error;
@@ -15,7 +16,7 @@ pub use specs::{
     Builder, DispatcherBuilder, Entity as EcsEntity, ReadStorage, World, WorldExt,
 };
 
-use crate::addr::ConnectionArgs;
+use crate::{addr::ConnectionArgs, revertclock::RevertClock};
 use byteorder::{ByteOrder, LittleEndian};
 use common::{
     character::{CharacterId, CharacterItem},
@@ -64,7 +65,7 @@ use common_net::{
     sync::WorldSyncExt,
 };
 use common_state::State;
-use common_systems::{add_local_systems, add_rewind_systems};
+use common_systems::add_local_systems;
 use comp::BuffKind;
 use hashbrown::{HashMap, HashSet};
 use image::DynamicImage;
@@ -237,9 +238,7 @@ pub struct Client {
 
     local_command_gen: CommandGenerator,
     next_control: Controller,
-    inter_tick_reverted_time: Option<Duration>,
+    revert_clock: RevertClock,
-    inter_tick_time_syncs: usize,
-    rewind_fluctuation_budget: f64,
 
     network: Option<Network>,
     participant: Option<Participant>,
@@ -724,9 +723,7 @@ impl Client {
 
             local_command_gen: CommandGenerator::default(),
             next_control: Controller::default(),
-            inter_tick_reverted_time: None,
+            revert_clock: RevertClock::default(),
-            inter_tick_time_syncs: 0,
-            rewind_fluctuation_budget: 0.0,
 
             network: Some(network),
             participant: Some(participant),
@@ -1705,8 +1702,7 @@ impl Client {
 
         // 1) Build up a list of events for this frame, to be passed to the frontend.
         let mut frontend_events = Vec::new();
-        self.inter_tick_reverted_time = None;
+        self.revert_clock.reset();
-        self.inter_tick_time_syncs = 0;
 
         // Prepare for new events
         {
@@ -1736,256 +1732,9 @@ impl Client {
         // Handle new messages from the server.
         frontend_events.append(&mut self.handle_new_messages()?);
 
-        // Simulate Ahead
+        // When the server sends a componenet update, rewind back
-
+        self.revert_clock.tick(&mut self.state, dt);
-        //TODO: also waro budget in non rewind workflow
+        //prepare this tick after we rewindet
-        //Dies hier. außerdem ist immernoch 200 als fixer wert im controler drinn
-
-        let time = self.state.ecs().read_resource::<Time>().0 as f64;
-
-        common_base::plot!("recived_time_sync", self.inter_tick_time_syncs as f64);
-
-        if let Some(rewind_time) = self.inter_tick_reverted_time {
-            let time = self.state.ecs().read_resource::<Time>().0 as f64;
-            let simulate_ahead = self
-                .state
-                .ecs()
-                .read_storage::<RemoteController>()
-                .get(self.entity())
-                .map(|rc| rc.simulate_ahead())
-                .unwrap_or_default();
-            // We substract `dt` here, as otherwise we
-            // Tick1: server_time=100ms dt=60ms ping=30 simulate_ahead=130ms,
-            // rewind_tick=130ms end_tick=100+130+60=290
-            // Tick2: server_time=130ms dt=30ms ping=30 simulate_ahead=130ms,
-            // rewind_tick=130ms end_tick=130+130+30=290
-            // Tick3: server_time=160ms dt=60ms ping=30 simulate_ahead=130ms,
-            // rewind_tick=130ms end_tick=160+130+60=350 with dt substraction
-            // Tick1: server_time=100ms dt=60ms ping=30 simulate_ahead=130ms,
-            // rewind_tick=70ms end_tick=100+70+60=230 Tick2: server_time=130ms
-            // dt=30ms ping=30 simulate_ahead=130ms, rewind_tick=100ms
-            // end_tick=130+100+30=260 Tick3: server_time=160ms dt=60ms ping=30
-            // simulate_ahead=130ms, rewind_tick=70ms end_tick=160+70+60=290
-            let simulate_ahead = simulate_ahead.max(dt) - dt;
-            let simulate_ahead = simulate_ahead + Duration::from_secs_f64(1.0 / 30.0);
-            /*
-            let x = if rewind_time > simulate_ahead + Duration::from_millis(25) {
-                common_base::plot!("xxx", 1.0);
-                common_base::plot!("gggggg", simulate_ahead.as_secs_f64() - rewind_time.as_secs_f64() );
-                simulate_ahead + Duration::from_millis(15)
-            } else if rewind_time < simulate_ahead - Duration::from_millis(25) {
-                common_base::plot!("xxx", -1.0);
-                simulate_ahead - Duration::from_millis(15)
-            } else {
-                common_base::plot!("xxx", 0.0);
-                simulate_ahead
-            };
-             */
-            {
-                let time = self.state.ecs().read_resource::<Time>().0;
-                common_base::plot!("tick_before", time);
-
-                let vel = self
-                    .state
-                    .ecs()
-                    .read_storage::<Vel>()
-                    .get(self.entity())
-                    .cloned()
-                    .unwrap_or(Vel(Vec3::zero()));
-
-                common_base::plot!("vel_x_before1", vel.0.x as f64);
-                common_base::plot!("vel_y_before1", vel.0.y as f64);
-                common_base::plot!("vel_z_before1", vel.0.z as f64);
-                let pos = self
-                    .state
-                    .ecs()
-                    .read_storage::<common::comp::Pos>()
-                    .get(self.entity())
-                    .cloned()
-                    .unwrap_or(common::comp::Pos(Vec3::zero()));
-
-                common_base::plot!("pos_x_before1", pos.0.x as f64);
-                common_base::plot!("pos_y_before1", pos.0.y as f64);
-                common_base::plot!("pos_z_before1", pos.0.z as f64);
-            }
-
-            common_base::plot!("rewind_time", rewind_time.as_secs_f64());
-            self.state.rewind_tick(
-                simulate_ahead,
-                |dispatch_builder| {
-                    add_rewind_systems(dispatch_builder);
-                },
-                false,
-            );
-
-            {
-                let time = self.state.ecs().read_resource::<Time>().0;
-                common_base::plot!("tick_afterwards1", time);
-                let vel = self
-                    .state
-                    .ecs()
-                    .read_storage::<Vel>()
-                    .get(self.entity())
-                    .cloned()
-                    .unwrap_or(Vel(Vec3::zero()));
-
-                common_base::plot!("vel_x_after1", vel.0.x as f64);
-                common_base::plot!("vel_y_after1", vel.0.y as f64);
-                common_base::plot!("vel_z_after1", vel.0.z as f64);
-                let pos = self
-                    .state
-                    .ecs()
-                    .read_storage::<common::comp::Pos>()
-                    .get(self.entity())
-                    .cloned()
-                    .unwrap_or(common::comp::Pos(Vec3::zero()));
-
-                common_base::plot!("pos_x_after1", pos.0.x as f64);
-                common_base::plot!("pos_y_after1", pos.0.y as f64);
-                common_base::plot!("pos_z_after1", pos.0.z as f64);
-            }
-        }
-
-        /*
-        let mut rewind_time = Duration::from_secs_f64(0.0);
-        const WARP_PERCENT: f64 = 0.05; // make sure we end up not further than 5% from the estimated tick
-        let mut target_smooth_dt = dt.as_secs_f64();
-        common_base::plot!("recived_time_sync", 0.0);
-        if let Some(reverted_time) = self.inter_tick_reverted_time {
-            // At smooth_time we wouldn't notice any rewind
-            let smooth_time = reverted_time + dt;
-            common_base::plot!("recived_time_sync", 1.0);
-            common_base::plot!("reverted_time", reverted_time.as_secs_f64());
-            let time = self.state.ecs().read_resource::<Time>().0 as f64;
-            let simulate_ahead = self
-                .state
-                .ecs()
-                .read_storage::<RemoteController>()
-                .get(self.entity())
-                .map(|rc| rc.simulate_ahead())
-                .unwrap_or_default();
-            // We substract `dt` here, as otherwise we
-            // Tick1: server_time=100ms dt=60ms ping=30 simulate_ahead=130ms, rewind_tick=130ms end_tick=100+130+60=290
-            // Tick2: server_time=130ms dt=30ms ping=30 simulate_ahead=130ms, rewind_tick=130ms end_tick=130+130+30=290
-            // Tick3: server_time=160ms dt=60ms ping=30 simulate_ahead=130ms, rewind_tick=130ms end_tick=160+130+60=350
-            // with dt substraction
-            // Tick1: server_time=100ms dt=60ms ping=30 simulate_ahead=130ms, rewind_tick=70ms end_tick=100+70+60=230
-            // Tick2: server_time=130ms dt=30ms ping=30 simulate_ahead=130ms, rewind_tick=100ms end_tick=130+100+30=260
-            // Tick3: server_time=160ms dt=60ms ping=30 simulate_ahead=130ms, rewind_tick=70ms end_tick=160+70+60=290
-            let simulate_ahead = simulate_ahead.max(dt) - dt;
-            // measurements lead to the effect that smooth_diff is == 0.0 when we add 2 server ticks here.
-            let simulate_ahead = simulate_ahead + Duration::from_secs_f64(1.0 / 30.0);
-            rewind_time = simulate_ahead;
-
-            // Simulate_ahead still fluctionates because Server Tick != Client Tick, and we cant
-            // control the phase in which the sync happens.
-            // In order to dampen it, we calculate the target_smooth_dt and make sure to not derive
-            // to much from it
-
-            ERROR, muss man das hier swappen ?
-            target_smooth_dt = reverted_time.as_secs_f64() - simulate_ahead.as_secs_f64();
-            // we store it, and will apply it over the course of the next ticks
-            self.rewind_fluctuation_budget = target_smooth_dt;
-            common_base::plot!("new_rewind_fluctuation_budget", self.rewind_fluctuation_budget);
-        }
-        common_base::plot!("rewind_time", rewind_time.as_secs_f64());
-
-
-        // we need to subtract the normal dt as we have a separate tick call for it.
-        // make it positive as we wont allow direct go in past
-        let corrected_target_smooth_dt = (target_smooth_dt - dt.as_secs_f64()).max(0.0);
-        common_base::plot!("corrected_target_smooth_dt", corrected_target_smooth_dt);
-
-        // apply our budget to rewind_time
-        let mut smooth_rewind_time = rewind_time.as_secs_f64();
-        smooth_rewind_time += self.rewind_fluctuation_budget;
-        let xxx =  smooth_rewind_time.clamp( corrected_target_smooth_dt * (1.0-WARP_PERCENT), corrected_target_smooth_dt * (1.0+WARP_PERCENT));
-        common_base::plot!("xxx", xxx);
-        smooth_rewind_time = xxx;
-        self.rewind_fluctuation_budget -= smooth_rewind_time - rewind_time.as_secs_f64();
-
-        common_base::plot!("rewind_fluctuation_budget", self.rewind_fluctuation_budget);
-        common_base::plot!("target_smooth_dt", target_smooth_dt);
-
-
-        tracing::warn!(?smooth_rewind_time, ?dt, "simulating ahead again");
-        self.state.rewind_tick(
-            Duration::from_secs_f64(smooth_rewind_time),
-            |dispatch_builder| {
-                add_rewind_systems(dispatch_builder);
-            },
-            false,
-        );
-
-         */
-
-        /*
-           if let Some(rewind_time) = self.inter_tick_reverted_time {
-               common_base::plot!("recived_time_sync", 1.0);
-               let _time = self.state.ecs().read_resource::<Time>().0 as f64;
-               let simulate_ahead = self
-                   .state
-                   .ecs()
-                   .read_storage::<RemoteController>()
-                   .get(self.entity())
-                   .map(|rc| rc.simulate_ahead())
-                   .unwrap_or_default();
-               // We substract `dt` here, as otherwise we
-               // Tick1: server_time=100ms dt=60ms ping=30 simulate_ahead=130ms,
-               // rewind_tick=130ms end_tick=100+130+60=290
-               // Tick2: server_time=130ms dt=30ms ping=30 simulate_ahead=130ms,
-               // rewind_tick=130ms end_tick=130+130+30=290
-               // Tick3: server_time=160ms dt=60ms ping=30 simulate_ahead=130ms,
-               // rewind_tick=130ms end_tick=160+130+60=350 with dt substraction
-               // Tick1: server_time=100ms dt=60ms ping=30 simulate_ahead=130ms,
-               // rewind_tick=70ms end_tick=100+70+60=230 Tick2: server_time=130ms
-               // dt=30ms ping=30 simulate_ahead=130ms, rewind_tick=100ms
-               // end_tick=130+100+30=260 Tick3: server_time=160ms dt=60ms ping=30
-               // simulate_ahead=130ms, rewind_tick=70ms end_tick=160+70+60=290
-               let simulate_ahead = simulate_ahead.max(dt) - dt;
-               // measurements lead to the effect that smooth_diff is == 0.0 when we add 2
-               // server ticks here.
-               let simulate_ahead = simulate_ahead + Duration::from_secs_f64(1.0 / 30.0);
-
-               // Simulate_ahead still fluctionates because Server Tick != Client Tick, and we cant
-               // control the phase in which the sync happens.
-               // In order to dampen it, we calculate the smooth_time and make sure to not derive
-               // to much from it
-               let smooth_diff = simulate_ahead.as_secs_f64() - rewind_time.as_secs_f64();
-
-               const WARP_PERCENT: f64 = 0.05; // make sure we end up not further than 5% from the estimated tick
-               let mut warp_budget = dt.as_secs_f64() * WARP_PERCENT;
-               if smooth_diff.abs() > warp_budget {
-                   self.rewind_fluctuation_budget += (dt.as_secs_f64() * (1.0-WARP_PERCENT)) * smooth_diff.signum();
-                   warp_budget = warp_budget.clamp(-warp_budget, warp_budget);
-               }
-
-               // extend from
-               let add = if smooth_diff >= 0.0 {
-                   smooth_diff.min(self.rewind_fluctuation_budget).max(0.0)
-               } else {
-                   smooth_diff.max(self.rewind_fluctuation_budget).min(0.0)
-               };
-               self.rewind_fluctuation_budget -= add;
-               let simulate_ahead = Duration::from_secs_f64(time + rewind_time.as_secs_f64() + add);
-
-               common_base::plot!("rewind_fluctuation_budget", self.rewind_fluctuation_budget);
-               common_base::plot!("smooth_diff", smooth_diff);
-
-               //let simulate_ahead = simulate_ahead.max(dt)/* - dt*/;
-               //let simulate_ahead = rewind_time.min(simulate_ahead);
-               tracing::warn!(?simulate_ahead, ?dt, "simulating ahead again");
-               common_base::plot!("rewind_time", rewind_time.as_secs_f64());
-               self.state.rewind_tick(
-                   simulate_ahead,
-                   |dispatch_builder| {
-                       add_rewind_systems(dispatch_builder);
-                   },
-                   false,
-               );
-           }
-
-        */
 
         // 2) Handle input from frontend.
         // Pass character actions from frontend input to the player's entity.
@@ -1993,10 +1742,11 @@ impl Client {
             prof_span!("handle and send inputs");
             self.next_control.inputs = inputs;
             let con = std::mem::take(&mut self.next_control);
-            let time = Duration::from_secs_f64(self.state.ecs().read_resource::<Time>().0) + dt;
+            let this_tick_time =
+                Duration::from_secs_f64(self.state.ecs().read_resource::<Time>().0) + dt;
             let monotonic_time =
                 Duration::from_secs_f64(self.state.ecs().read_resource::<MonotonicTime>().0);
-            let rcon = self.local_command_gen.gen(time, con);
+            let rcon = self.local_command_gen.gen(this_tick_time, con);
             let commands = self
                 .state
                 .ecs()
@@ -2446,23 +2196,15 @@ impl Client {
     ) -> Result<(), Error> {
         prof_span!("handle_server_in_game_msg");
         match msg {
-            ServerGeneral::TimeSync(time) => {
+            ServerGeneral::TimeSync {
-                self.inter_tick_time_syncs += 1;
+                server_time,
-                // Even with a stable network, expect time to oscillate around the actual time
+                inter_tick_offset,
-                // by SERVER_TICK (33.3ms)
+            } => {
-                let old_time = self.state.ecs().read_resource::<Time>().0;
+                let old_client_time = self.state.ecs().read_resource::<Time>().0;
-                let diff = old_time - time.0;
+                self.state.ecs().write_resource::<Time>().0 = server_time.0;
-                self.state.ecs().write_resource::<Time>().0 = time.0;
+                self.revert_clock
-                if diff > 0.0 {
+                    .sync(old_client_time, server_time, inter_tick_offset);
-                    tracing::warn!(?old_time, ?diff, "Time was reverted by server");
-                    let rewind_time = self.inter_tick_reverted_time.unwrap_or_default()
-                        + Duration::from_secs_f64(diff);
-                    self.inter_tick_reverted_time = Some(rewind_time);
-                } else {
-                    tracing::warn!(?old_time, ?diff, "Time was advanced by server");
-                }
             },
-
             ServerGeneral::AckControl {
                 acked_ids,
                 highest_ahead_command,

client/src/revertclock.rs

@@ -0,0 +1,249 @@
+use common::{
+    comp::{RemoteController, Vel},
+    resources::{DeltaTime, MonotonicTime, PlayerEntity, Time, TimeOfDay},
+};
+use common_state::State;
+use common_systems::add_rewind_systems;
+use specs::WorldExt;
+use std::time::Duration;
+use vek::{ops::Clamp, Vec3};
+
+#[derive(Default)]
+pub(crate) struct RevertClock {
+    reverted_time: Option<Duration>,
+    time_syncs: usize,
+}
+
+impl RevertClock {
+    pub(crate) fn reset(&mut self) {
+        self.reverted_time = None;
+        self.time_syncs = 0;
+    }
+
+    // The server might need up to 33ms to calcualte its tick. It will send this
+    // time with it, so that we can substract it from
+    pub(crate) fn sync(
+        &mut self,
+        old_client_time: f64,
+        new_server_time: Time,
+        _inter_tick_offset: Duration,
+    ) {
+        self.time_syncs += 1;
+        // Even with a stable network, expect time to oscillate around the actual time
+        // by SERVER_TICK (33.3ms)
+        let diff = old_client_time - new_server_time.0;
+        if diff > 0.0 {
+            tracing::warn!(?old_client_time, ?diff, "Time was reverted by server");
+            let rewind_time =
+                self.reverted_time.unwrap_or_default() + Duration::from_secs_f64(diff);
+            self.reverted_time = Some(rewind_time);
+        } else {
+            tracing::warn!(?old_client_time, ?diff, "Time was advanced by server");
+        }
+    }
+
+    /// Rewind local changes after the server send some old state
+    fn rewind_tick(simulate_ahead: Duration, state: &mut State) {
+        common_base::plot!("simulate_ahead", simulate_ahead.as_secs_f64());
+
+        // store changes
+        let time_of_day = state.ecs().read_resource::<TimeOfDay>().0;
+        let monotonic_time = state.ecs().read_resource::<MonotonicTime>().0;
+        let delta_time = state.ecs().read_resource::<DeltaTime>().0;
+
+        const MAX_INCREMENTS: usize = 100; // The maximum number of collision tests per tick
+        const STEP_SEC: f64 = 0.04;
+        let increments =
+            ((simulate_ahead.as_secs_f64() / STEP_SEC).ceil() as usize).clamped(1, MAX_INCREMENTS);
+        for _ in 0..increments {
+            let partial = simulate_ahead / (increments as u32);
+            state.tick(
+                partial,
+                |dispatch_builder| {
+                    add_rewind_systems(dispatch_builder);
+                },
+                false,
+                None, // TODO: fix metrics
+            );
+        }
+
+        // rewind changes
+        state.ecs().write_resource::<TimeOfDay>().0 = time_of_day;
+        state.ecs().write_resource::<MonotonicTime>().0 = monotonic_time;
+        state.ecs().write_resource::<DeltaTime>().0 = delta_time;
+    }
+
+    pub(crate) fn tick(&mut self, state: &mut State, dt: Duration) {
+        let entity = state
+            .ecs()
+            .read_resource::<PlayerEntity>()
+            .0
+            .expect("Client::entity should always have PlayerEntity be Some");
+
+        common_base::plot!("recived_time_sync", self.time_syncs as f64);
+
+        let rewind_time = match self.reverted_time {
+            Some(rewind_time) => rewind_time,
+            None => return,
+        };
+
+        let simulate_ahead = state
+            .ecs()
+            .read_storage::<RemoteController>()
+            .get(entity)
+            .map(|rc| rc.simulate_ahead())
+            .unwrap_or_default();
+        // We substract `dt` here, as otherwise we
+        // Tick1: server_time=100ms dt=60ms ping=30 simulate_ahead=130ms,
+        // rewind_tick=130ms end_tick=100+130+60=290
+        // Tick2: server_time=130ms dt=30ms ping=30 simulate_ahead=130ms,
+        // rewind_tick=130ms end_tick=130+130+30=290
+        // Tick3: server_time=160ms dt=60ms ping=30 simulate_ahead=130ms,
+        // rewind_tick=130ms end_tick=160+130+60=350 with dt substraction
+        // Tick1: server_time=100ms dt=60ms ping=30 simulate_ahead=130ms,
+        // rewind_tick=70ms end_tick=100+70+60=230 Tick2: server_time=130ms
+        // dt=30ms ping=30 simulate_ahead=130ms, rewind_tick=100ms
+        // end_tick=130+100+30=260 Tick3: server_time=160ms dt=60ms ping=30
+        // simulate_ahead=130ms, rewind_tick=70ms end_tick=160+70+60=290
+        let simulate_ahead = simulate_ahead.max(dt) - dt;
+        let simulate_ahead = simulate_ahead + Duration::from_secs_f64(1.0 / 30.0);
+        /*
+        let x = if rewind_time > simulate_ahead + Duration::from_millis(25) {
+            common_base::plot!("xxx", 1.0);
+            common_base::plot!("gggggg", simulate_ahead.as_secs_f64() - rewind_time.as_secs_f64() );
+            simulate_ahead + Duration::from_millis(15)
+        } else if rewind_time < simulate_ahead - Duration::from_millis(25) {
+            common_base::plot!("xxx", -1.0);
+            simulate_ahead - Duration::from_millis(15)
+        } else {
+            common_base::plot!("xxx", 0.0);
+            simulate_ahead
+        };
+         */
+        {
+            let last_tick_time = state.ecs().read_resource::<Time>().0 as f64;
+            common_base::plot!("tick_before", last_tick_time);
+
+            let vel = state
+                .ecs()
+                .read_storage::<Vel>()
+                .get(entity)
+                .cloned()
+                .unwrap_or(Vel(Vec3::zero()));
+
+            common_base::plot!("vel_x_before1", vel.0.x as f64);
+            common_base::plot!("vel_y_before1", vel.0.y as f64);
+            common_base::plot!("vel_z_before1", vel.0.z as f64);
+            let pos = state
+                .ecs()
+                .read_storage::<common::comp::Pos>()
+                .get(entity)
+                .cloned()
+                .unwrap_or(common::comp::Pos(Vec3::zero()));
+
+            common_base::plot!("pos_x_before1", pos.0.x as f64);
+            common_base::plot!("pos_y_before1", pos.0.y as f64);
+            common_base::plot!("pos_z_before1", pos.0.z as f64);
+        }
+
+        common_base::plot!("rewind_time", rewind_time.as_secs_f64());
+        RevertClock::rewind_tick(simulate_ahead, state);
+
+        {
+            let time = state.ecs().read_resource::<Time>().0 as f64;
+            common_base::plot!("tick_afterwards1", time);
+            let vel = state
+                .ecs()
+                .read_storage::<Vel>()
+                .get(entity)
+                .cloned()
+                .unwrap_or(Vel(Vec3::zero()));
+
+            common_base::plot!("vel_x_after1", vel.0.x as f64);
+            common_base::plot!("vel_y_after1", vel.0.y as f64);
+            common_base::plot!("vel_z_after1", vel.0.z as f64);
+            let pos = state
+                .ecs()
+                .read_storage::<common::comp::Pos>()
+                .get(entity)
+                .cloned()
+                .unwrap_or(common::comp::Pos(Vec3::zero()));
+
+            common_base::plot!("pos_x_after1", pos.0.x as f64);
+            common_base::plot!("pos_y_after1", pos.0.y as f64);
+            common_base::plot!("pos_z_after1", pos.0.z as f64);
+        }
+
+        /*
+        let mut rewind_time = Duration::from_secs_f64(0.0);
+        const WARP_PERCENT: f64 = 0.05; // make sure we end up not further than 5% from the estimated tick
+        let mut target_smooth_dt = dt.as_secs_f64();
+        common_base::plot!("recived_time_sync", 0.0);
+        if let Some(reverted_time) = self.inter_tick_reverted_time {
+            // At smooth_time we wouldn't notice any rewind
+            let smooth_time = reverted_time + dt;
+            common_base::plot!("recived_time_sync", 1.0);
+            common_base::plot!("reverted_time", reverted_time.as_secs_f64());
+            let time = self.state.ecs().read_resource::<Time>().0 as f64;
+            let simulate_ahead = self
+                .state
+                .ecs()
+                .read_storage::<RemoteController>()
+                .get(entity)
+                .map(|rc| rc.simulate_ahead())
+                .unwrap_or_default();
+            // We substract `dt` here, as otherwise we
+            // Tick1: server_time=100ms dt=60ms ping=30 simulate_ahead=130ms, rewind_tick=130ms end_tick=100+130+60=290
+            // Tick2: server_time=130ms dt=30ms ping=30 simulate_ahead=130ms, rewind_tick=130ms end_tick=130+130+30=290
+            // Tick3: server_time=160ms dt=60ms ping=30 simulate_ahead=130ms, rewind_tick=130ms end_tick=160+130+60=350
+            // with dt substraction
+            // Tick1: server_time=100ms dt=60ms ping=30 simulate_ahead=130ms, rewind_tick=70ms end_tick=100+70+60=230
+            // Tick2: server_time=130ms dt=30ms ping=30 simulate_ahead=130ms, rewind_tick=100ms end_tick=130+100+30=260
+            // Tick3: server_time=160ms dt=60ms ping=30 simulate_ahead=130ms, rewind_tick=70ms end_tick=160+70+60=290
+            let simulate_ahead = simulate_ahead.max(dt) - dt;
+            // measurements lead to the effect that smooth_diff is == 0.0 when we add 2 server ticks here.
+            let simulate_ahead = simulate_ahead + Duration::from_secs_f64(1.0 / 30.0);
+            rewind_time = simulate_ahead;
+
+            // Simulate_ahead still fluctionates because Server Tick != Client Tick, and we cant
+            // control the phase in which the sync happens.
+            // In order to dampen it, we calculate the target_smooth_dt and make sure to not derive
+            // to much from it
+
+            ERROR, muss man das hier swappen ?
+            target_smooth_dt = reverted_time.as_secs_f64() - simulate_ahead.as_secs_f64();
+            // we store it, and will apply it over the course of the next ticks
+            self.rewind_fluctuation_budget = target_smooth_dt;
+            common_base::plot!("new_rewind_fluctuation_budget", self.rewind_fluctuation_budget);
+        }
+        common_base::plot!("rewind_time", rewind_time.as_secs_f64());
+
+
+        // we need to subtract the normal dt as we have a separate tick call for it.
+        // make it positive as we wont allow direct go in past
+        let corrected_target_smooth_dt = (target_smooth_dt - dt.as_secs_f64()).max(0.0);
+        common_base::plot!("corrected_target_smooth_dt", corrected_target_smooth_dt);
+
+        // apply our budget to rewind_time
+        let mut smooth_rewind_time = rewind_time.as_secs_f64();
+        smooth_rewind_time += self.rewind_fluctuation_budget;
+        let xxx =  smooth_rewind_time.clamp( corrected_target_smooth_dt * (1.0-WARP_PERCENT), corrected_target_smooth_dt * (1.0+WARP_PERCENT));
+        common_base::plot!("xxx", xxx);
+        smooth_rewind_time = xxx;
+        self.rewind_fluctuation_budget -= smooth_rewind_time - rewind_time.as_secs_f64();
+
+        common_base::plot!("rewind_fluctuation_budget", self.rewind_fluctuation_budget);
+        common_base::plot!("target_smooth_dt", target_smooth_dt);
+
+
+        tracing::warn!(?smooth_rewind_time, ?dt, "simulating ahead again");
+        self.state.rewind_tick(
+            Duration::from_secs_f64(smooth_rewind_time),
+            |dispatch_builder| {
+                add_rewind_systems(dispatch_builder);
+            },
+            false,
+        );
+         */
+    }
+}

common/net/src/msg/ecs_packet.rs

@@ -24,6 +24,7 @@ macro_rules! comp_packet {
                 Pos(comp::Pos),
                 Vel(comp::Vel),
                 Ori(comp::Ori),
+                PhysicsState(comp::PhysicsState),
             }
         }
 
@@ -36,6 +37,7 @@ macro_rules! comp_packet {
                 Pos(PhantomData<comp::Pos>),
                 Vel(PhantomData<comp::Vel>),
                 Ori(PhantomData<comp::Ori>),
+                PhysicsState(PhantomData<comp::PhysicsState>),
             }
         }
 
@@ -57,6 +59,9 @@ macro_rules! comp_packet {
                     Self::Ori(comp) => {
                         sync::handle_interp_insert(comp, entity, world, true)
                     },
+                    Self::PhysicsState(comp) => {
+                        crate::sync::packet::handle_insert(comp, entity, world);
+                    },
                 }
             }
 
@@ -75,6 +80,9 @@ macro_rules! comp_packet {
                     Self::Ori(comp) => {
                         sync::handle_interp_modify(comp, entity, world, true)
                     },
+                    Self::PhysicsState(comp) => {
+                        crate::sync::packet::handle_modify(comp, entity, world);
+                    },
                 }
             }
 
@@ -92,6 +100,9 @@ macro_rules! comp_packet {
                     EcsCompPhantom::Ori(_) => {
                         sync::handle_interp_remove::<comp::Ori>(entity, world)
                     },
+                    EcsCompPhantom::PhysicsState(_) => {
+                        crate::sync::packet::handle_remove::<comp::PhysicsState>(entity, world);
+                    },
                 }
             }
         }

common/net/src/msg/server.rs

@@ -142,7 +142,10 @@ pub enum ServerGeneral {
     CharacterSuccess,
     SpectatorSuccess(Vec3<f32>),
     //Ingame related
-    TimeSync(Time),
+    TimeSync {
+        server_time: Time,
+        inter_tick_offset: Duration,
+    },
     AckControl {
         acked_ids: HashSet<u64>,
         /// measured by the time the furthest command to become active <>
@@ -324,7 +327,7 @@ impl ServerMsg {
                         },
                         //Ingame related
                         ServerGeneral::GroupUpdate(_)
-                        | ServerGeneral::TimeSync(_)
+                        | ServerGeneral::TimeSync { .. }
                         | ServerGeneral::AckControl { .. }
                         | ServerGeneral::Invite { .. }
                         | ServerGeneral::InvitePending(_)

common/net/src/sync/interpolation.rs

@@ -2,7 +2,7 @@
 // `common_net` is downstream of `common`, and an `InterpolationSystem` that
 // applies them
 use super::InterpolatableComponent;
-use common::comp::{Ori, Pos, Vel};
+use common::comp::{Ori, Pos, Vel, PhysicsState};
 use specs::Component;
 use tracing::warn;
 use vek::ops::{Lerp, Slerp};
@@ -182,4 +182,4 @@ impl InterpolatableComponent for Ori {
 
         Ori::new(Slerp::slerp(self.to_quat(), out, PHYSICS_VS_EXTRAPOLATION_FACTOR).normalized())
     }
-}
+}

common/net/src/sync/mod.rs

@@ -2,7 +2,7 @@
 // sync arises
 pub mod interpolation;
 mod net_sync;
-mod packet;
+pub (crate) mod packet;
 mod sync_ext;
 mod track;
 

common/src/comp/remote_controller.rs

@@ -20,6 +20,7 @@ pub struct RemoteController {
     existing_commands: HashSet<u64>,
     max_hold: Duration,
     avg_latency: Duration,
+    avg_ahead_time: Duration,
 }
 
 #[derive(Clone, Debug, Serialize, Deserialize)]
@@ -105,7 +106,7 @@ impl RemoteController {
         monotonic_time: Duration,
         highest_ahead_command: f64,
     ) {
-        // calculating avg_latency.
+        // calculating avg_ahead_time.
         //  - server returns the time the furthest away command has left till it becomes
         //    active. As the server time is constant and we stored this value locally,
         //    we use it to calculate the first ahead_command for the first command in
@@ -113,83 +114,54 @@ impl RemoteController {
         //  - we try to keep the remote_ahead in a specific window to allow for
         //    retransmittion and remote tick time
 
+        // Buffer we try to keep on the server, make this a config
+        const AHEAD_TARGET: f64 = 0.055;
+        const AHEAD_TARGET_DIFF: f64 = 0.005;
+        const AHEAD_TARGET_STEP: Duration = Duration::from_millis(2);
+        const AHEAD_TARGET_NO_ACK_STEP: Duration = Duration::from_nanos(500000);
+
         // find time it took from client -> server
         let high_filter = self
             .commands
             .iter()
             .filter(|c| ids.contains(&c.id) && c.first_acked_monotonic_time.is_none());
         if let Some(highest) = high_filter.max_by_key(|c| c.action_time) {
-            let remote_time = highest.action_time.as_secs_f64() - highest_ahead_command;
+            if let Some(first_send_monotonic_time) = highest.first_send_monotonic_time {
-            //let latency = highest.first_send_simulate_ahead_time.unwrap_or_default() -
+                let latency = monotonic_time - first_send_monotonic_time;
-            // remote_time;
+                self.avg_latency = Duration::from_secs_f64(
-            common_base::plot!("prob_remote_time", remote_time);
+                    self.avg_latency.as_secs_f64() * 0.99 + latency.as_secs_f64() * 0.01,
-            //common_base::plot!("prob_avg_latency", latency);
+                );
-            //let low_filter = self.commands.iter().filter(|c| ids.contains(&c.id) &&
+            }
-            // c.first_send_monotonic_time == highest.first_send_monotonic_time);
             let low_filter = self
                 .commands
                 .iter()
                 .filter(|c| ids.contains(&c.id) && c.first_acked_monotonic_time.is_none());
             if let Some(lowest) = low_filter.min_by_key(|c| c.action_time) {
                 let low_high_diff = highest.action_time - lowest.action_time;
-                // if this is 50ms, it means the lowest command arrived at server 50 before it
+                // if this is 50ms, it means the lowest command arrived at server 50ms before it
                 // was used
-                common_base::plot!("highest_ahead_command", highest_ahead_command);
                 let ahead_time = highest_ahead_command - low_high_diff.as_secs_f64();
                 common_base::plot!("low_high_diff", low_high_diff.as_secs_f64());
                 common_base::plot!("ahead_time", ahead_time);
-                const LOWER_END: f64 = 0.18;
+                let avg_ahead_time = (lowest.first_send_simulate_ahead_time.unwrap_or_default()
-                const UPPER_END: f64 = 0.22;
+                    - ahead_time)
-                //if ahead_time > 2.0 {
+                    .max(0.0)
-                let len = self.commands.len();
+                    + AHEAD_TARGET;
-                tracing::error!(
+                // avg_ahead_time fluctuates by 1 dt, so we average it.
-                    ?ahead_time,
+                self.avg_ahead_time = Duration::from_secs_f64(
-                    ?ids,
+                    self.avg_ahead_time.as_secs_f64() * 0.995 + avg_ahead_time * 0.005,
-                    ?highest_ahead_command,
-                    ?highest,
-                    ?lowest,
-                    ?len,
-                    "bigger2"
                 );
-                //}
-                if ahead_time < LOWER_END {
-                    self.avg_latency += Duration::from_millis(10);
-                }
-                if ahead_time > UPPER_END && self.avg_latency > Duration::from_millis(3) {
-                    self.avg_latency -= Duration::from_millis(3);
-                }
             }
+        } else {
+            self.avg_ahead_time += AHEAD_TARGET_NO_ACK_STEP;
+            tracing::warn!(?self.avg_ahead_time, "No Highest");
         }
 
-        for c in &mut self.commands {
+        for c in &mut self.commands.iter_mut().filter(|c| ids.contains(&c.id)) {
             c.first_acked_monotonic_time = Some(monotonic_time);
         }
 
-        /*
+        common_base::plot!("avg_ahead_time", self.avg_ahead_time.as_secs_f64());
-        let mut lowest_monotonic_time = None;
-        for c in &mut self.commands {
-            let new_acked = c.first_acked_monotonic_time.is_none() && ids.contains(&c.id);
-            if new_acked {
-                c.first_acked_monotonic_time = Some(monotonic_time);
-                if c.first_send_monotonic_time.map_or(false, |mt| {
-                    mt < lowest_monotonic_time.unwrap_or(monotonic_time)
-                }) {
-                    lowest_monotonic_time = c.first_send_monotonic_time;
-                }
-            }
-        }
-        if let Some(lowest_monotonic_time) = lowest_monotonic_time {
-            if let Some(latency) = monotonic_time.checked_sub(lowest_monotonic_time) {
-                common_base::plot!("latency", latency.as_secs_f64());
-                self.avg_latency = ((99 * self.avg_latency + latency) / 100).max(latency);
-            } else {
-                warn!(
-                    "latency is negative, this should never be the case as this value is not \
-                     synced and monotonic!"
-                );
-            }
-        }*/
-        common_base::plot!("avg_latency", self.avg_latency.as_secs_f64());
     }
 
     /// prepare commands for sending
@@ -305,19 +277,22 @@ impl RemoteController {
         Some(result)
     }
 
-    /// the average latency is 300ms by default and will be adjusted over time
+    /// the average latency is 500ms by default and will be adjusted over time
     /// with every Ack the server sends its local tick time at the Ack
     /// so we can calculate how much time was spent for 1 way from
     /// server->client and assume that this is also true for client->server
     /// latency
-    pub fn avg_latency(&self) -> Duration { self.avg_latency }
+    //pub fn avg_latency(&self) -> Duration { self.avg_latency }
 
+    /// In contrast to avg_latency this calculates how much ahead we should
+    /// simulate in order to be just received on the server in time
     pub fn simulate_ahead(&self) -> Duration {
-        //const FIXED_OFFSET: Duration = Duration::from_millis(0);
+        const OVERWRITE_SIMULATE_AHEAD: Option<Duration> = None; // Some(Durations::from_millis(1100));
-        //self.avg_latency() + FIXED_OFFSET
+        if let Some(d) = OVERWRITE_SIMULATE_AHEAD {
-        // TODO:: mocked, as we use it internally for the new input functions and assume
+            d
-        // that time - simulate ahead = server time iirc
+        } else {
-        Duration::from_millis(200)
+            self.avg_ahead_time
+        }
     }
 }
 
@@ -327,7 +302,8 @@ impl Default for RemoteController {
             commands: VecDeque::new(),
             existing_commands: HashSet::new(),
             max_hold: Duration::from_secs(5),
-            avg_latency: Duration::from_millis(50),
+            avg_latency: Duration::from_millis(500),
+            avg_ahead_time: Duration::from_millis(500),
         }
     }
 }

common/state/src/state.rs

@@ -590,37 +590,6 @@ impl State {
         self.ecs.write_resource::<TerrainChanges>().modified_blocks = modified_blocks;
     }
 
-    /// Rewind local changes after the server send some old state
-    pub fn rewind_tick(
-        &mut self,
-        simulate_ahead: Duration,
-        add_systems: impl Fn(&mut DispatcherBuilder) + Clone,
-        update_terrain_and_regions: bool,
-    ) {
-        common_base::plot!("simulate_ahead", simulate_ahead.as_secs_f64());
-        let time_of_day = self.ecs.read_resource::<TimeOfDay>().0;
-        let _time = self.ecs.read_resource::<Time>().0;
-        let monotonic_time = self.ecs.read_resource::<MonotonicTime>().0;
-        let delta_time = self.ecs.read_resource::<DeltaTime>().0;
-
-        const MAX_INCREMENTS: usize = 100; // The maximum number of collision tests per tick
-        const STEP_SEC: f64 = 0.04;
-        let increments =
-            ((simulate_ahead.as_secs_f64() / STEP_SEC).ceil() as usize).clamped(1, MAX_INCREMENTS);
-        for _i in 0..increments {
-            //tracing::trace!(?i, ?increments, "subtick");
-            let partial = simulate_ahead / (increments as u32);
-            self.tick(partial, add_systems.clone(), update_terrain_and_regions);
-        }
-
-        // rewind changes
-
-        self.ecs.write_resource::<TimeOfDay>().0 = time_of_day;
-        //self.ecs.write_resource::<Time>().0 = time;
-        self.ecs.write_resource::<MonotonicTime>().0 = monotonic_time;
-        self.ecs.write_resource::<DeltaTime>().0 = delta_time;
-    }
-
     /// Execute a single tick, simulating the game state by the given duration.
     pub fn tick(
         &mut self,

common/systems/src/predict_controller.rs

@@ -65,8 +65,8 @@ impl<'a> System<'a> for Sys {
                 for a in r.actions {
                     if let common::comp::ControlAction::StartInput {
                         input,
-                        target_entity,
+                        target_entity: _,
-                        select_pos,
+                        select_pos: _,
                     } = a
                     {
                         if input == common::comp::InputKind::Jump {

server/src/client.rs

@@ -103,7 +103,7 @@ impl Client {
                     },
                     //In-game related
                     ServerGeneral::GroupUpdate(_)
-                    | ServerGeneral::TimeSync(_)
+                    | ServerGeneral::TimeSync{ .. }
                     | ServerGeneral::AckControl(_, _)
                     | ServerGeneral::Invite { .. }
                     | ServerGeneral::InvitePending(_)
@@ -177,7 +177,7 @@ impl Client {
                     },
                     //In-game related
                     ServerGeneral::GroupUpdate(_)
-                    | ServerGeneral::TimeSync(_)
+                    | ServerGeneral::TimeSync { .. }
                     | ServerGeneral::AckControl { .. }
                     | ServerGeneral::Invite { .. }
                     | ServerGeneral::InvitePending(_)

server/src/sys/entity_sync.rs

@@ -2,7 +2,7 @@ use super::sentinel::{DeletedEntities, TrackedStorages, UpdateTrackers};
 use crate::{
     client::Client,
     presence::{Presence, RegionSubscription},
-    Tick,
+    Tick, TickStart,
 };
 use common::{
     calendar::Calendar,
@@ -20,6 +20,7 @@ use common_net::{msg::ServerGeneral, sync::CompSyncPackage};
 use itertools::Either;
 use specs::{Entities, Join, Read, ReadExpect, ReadStorage, Write, WriteStorage};
 use vek::*;
+use common::comp::PhysicsState;
 
 /// This system will send physics updates to the client
 #[derive(Default)]
@@ -33,12 +34,14 @@ impl<'a> System<'a> for Sys {
         TrackedStorages<'a>,
         ReadExpect<'a, TimeOfDay>,
         ReadExpect<'a, Time>,
+        ReadExpect<'a, TickStart>,
         ReadExpect<'a, Calendar>,
         ReadExpect<'a, RegionMap>,
         ReadExpect<'a, UpdateTrackers>,
         ReadStorage<'a, Pos>,
         ReadStorage<'a, Vel>,
         ReadStorage<'a, Ori>,
+        ReadStorage<'a, PhysicsState>,
         ReadStorage<'a, RegionSubscription>,
         ReadStorage<'a, Presence>,
         ReadStorage<'a, Client>,
@@ -63,12 +66,14 @@ impl<'a> System<'a> for Sys {
             tracked_storages,
             time_of_day,
             time,
+            tick_start,
             calendar,
             region_map,
             trackers,
             positions,
             velocities,
             orientations,
+            physics_states,
             subscriptions,
             presences,
             clients,
@@ -83,6 +88,11 @@ impl<'a> System<'a> for Sys {
     ) {
         let tick = tick.0;
 
+        //use rand::Rng;
+        //let _rng = rand::thread_rng();
+        //std::thread::sleep(std::time::Duration::from_millis(rng.gen_range(0..2) *
+        // 28));
+
         // Storages already provided in `TrackedStorages` that we need to use
         // for other things besides change detection.
         let uids = &tracked_storages.uid;
@@ -229,14 +239,15 @@ impl<'a> System<'a> for Sys {
                 for (client, _, client_entity, client_pos) in &mut subscribers {
                     let mut comp_sync_package = CompSyncPackage::new();
 
-                    for (_, entity, &uid, (&pos, last_pos), vel, ori, force_update, collider) in (
+                    for (_, entity, &uid, (&pos, last_pos), vel, ori, physic_state, force_update, collider) in (
                         region.entities(),
                         &entities,
                         uids,
                         (&positions, last_pos.mask().maybe()),
                         (&velocities, last_vel.mask().maybe()).maybe(),
                         (&orientations, last_vel.mask().maybe()).maybe(),
-                        force_updates.maybe(),
+                        (&physics_states, physics_states.mask().maybe()).maybe(),
+                        force_updates.mask().maybe(),
                         colliders.maybe(),
                     )
                         .join()
@@ -246,8 +257,7 @@ impl<'a> System<'a> for Sys {
                             // Don't send client physics updates about itself unless force update is
                             // set or the client is subject to
                             // server-authoritative physics
-                            true || force_update.map_or(false, |f| f.is_forced())
+                            true || is_rider.get(entity).is_some()
-                                || is_rider.get(entity).is_some()
                         } else if matches!(collider, Some(Collider::Voxel { .. })) {
                             // Things with a voxel collider (airships, etc.) need to have very
                             // stable physics so we always send updated
@@ -298,12 +308,32 @@ impl<'a> System<'a> for Sys {
                                 comp_sync_package.comp_modified(uid, *o);
                             }
                         }
+
+                        if let Some((physic_state, last_physic_state)) = physic_state {
+                            if last_physic_state.is_none() {
+                                comp_sync_package.comp_inserted(uid, physic_state.clone());
+                            } else if send_now {
+                                comp_sync_package.comp_modified(uid, physic_state.clone());
+                            }
+                        }
                     }
 
                     client.send_fallible(ServerGeneral::CompSync(
                         comp_sync_package,
                         force_updates.get(*client_entity).map_or(0, |f| f.counter()),
                     ));
+                    /*
+                    multiple problems
+                     - CompSync and TimeSync could (theoretically be received in 2 different ticks, client would be confused for 1 tick then
+                     - we dont send the client in which part of this tick we are sending this. Imaging a fluctuating server, that either needs 1ms or 100ms per tick.
+                       The client would get confused as the dt might be 1 ms, but the information arrives 99ms late because of server is running behind.
+                       As we send this info as fast as possible, this also is a problem when the server is running "ahead" (faster than 33ms)
+                       To mitigate this, we might use the Duration between now and TickStart
+                     */
+                    client.send_fallible(ServerGeneral::TimeSync {
+                        server_time: *time,
+                        inter_tick_offset: tick_start.0.elapsed(),
+                    });
                 }
             },
         );

server/src/sys/msg/ping.rs

@@ -4,7 +4,7 @@ use common::{
     resources::Time,
 };
 use common_ecs::{Job, Origin, Phase, System};
-use common_net::msg::{PingMsg, ServerGeneral};
+use common_net::msg::{PingMsg};
 use rayon::prelude::*;
 use specs::{Entities, ParJoin, Read, WriteStorage};
 use tracing::{debug, info};
@@ -47,7 +47,6 @@ impl<'a> System<'a> for Sys {
                     client.participant.as_mut().map(|p| p.try_fetch_event())
                 {}
 
-                client.send_fallible(ServerGeneral::TimeSync(*time));
                 let res = super::try_recv_all(client, 4, Self::handle_ping_msg);
 
                 match res {

voxygen/src/ecs/sys/interpolation.rs

@@ -45,9 +45,11 @@ impl<'a> System<'a> for Sys {
                 // Note, these values are specifically tuned for smoother motion with high
                 // network latency or low network sampling rate and for smooth
                 // block hopping (which is instantaneous)
-                const POS_LERP_RATE_FACTOR: f32 = 10.0;
+                //const POS_LERP_RATE_FACTOR: f32 = 10.0;
-                i.pos = Lerp::lerp(i.pos, pos.0 + vel.0 * 0.03, POS_LERP_RATE_FACTOR * dt.0);
+                //i.pos = Lerp::lerp(i.pos, pos.0 + vel.0 * 0.03, POS_LERP_RATE_FACTOR * dt.0);
-                i.ori = Ori::slerp(i.ori, *ori, base_ori_interp(body) * dt.0);
+                //i.ori = Ori::slerp(i.ori, *ori, base_ori_interp(body) * dt.0);
+                i.pos = pos.0;
+                i.ori = *ori;
             } else {
                 i.pos = pos.0;
                 i.ori = *ori;