From e8fa96142a0ca9337ff554e55943530200f6f4dd Mon Sep 17 00:00:00 2001
From: Martin Indra <martin.indra@mgn.cz>
Date: Tue, 19 Sep 2023 16:00:24 +0200
Subject: [PATCH] WIP

---
 Cargo.lock                          |  3 +
 crates/movement/Cargo.toml          |  7 ++-
 crates/movement/src/movement.rs     | 93 +++++++++++++++++++++++++++--
 crates/multiplayer/src/lib.rs       |  2 +-
 crates/multiplayer/src/playermsg.rs | 27 +++++++++
 5 files changed, 123 insertions(+), 9 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 9fc421c40..5f37820be 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2537,9 +2537,12 @@ dependencies = [
  "de_core",
  "de_index",
  "de_map",
+ "de_messages",
+ "de_multiplayer",
  "de_objects",
  "de_pathing",
  "de_types",
+ "fastrand 1.9.0",
  "glam",
  "parry2d",
  "parry3d",
diff --git a/crates/movement/Cargo.toml b/crates/movement/Cargo.toml
index bdac1f27b..b2b180972 100644
--- a/crates/movement/Cargo.toml
+++ b/crates/movement/Cargo.toml
@@ -16,12 +16,15 @@ categories.workspace = true
 de_core.workspace = true
 de_index.workspace = true
 de_map.workspace = true
+de_messages.workspace = true
+de_multiplayer.workspace = true
 de_objects.workspace = true
 de_pathing.workspace = true
 de_types.workspace = true
 
 # Other
 bevy.workspace = true
-parry3d.workspace = true
-parry2d.workspace = true
+fastrand.workspace = true
 glam.workspace = true
+parry2d.workspace = true
+parry3d.workspace = true
diff --git a/crates/movement/src/movement.rs b/crates/movement/src/movement.rs
index 167a92880..746c047a7 100644
--- a/crates/movement/src/movement.rs
+++ b/crates/movement/src/movement.rs
@@ -1,13 +1,16 @@
-use std::marker::PhantomData;
+use std::{marker::PhantomData, time::Duration};
 
 use bevy::prelude::*;
 use de_core::{
     gamestate::GameState,
-    objects::MovableSolid,
+    gconfig::GameConfig,
+    objects::{Local, MovableSolid},
     schedule::{Movement, PreMovement},
     state::AppState,
 };
 use de_map::size::MapBounds;
+use de_messages::ToPlayers;
+use de_multiplayer::{NetEntities, NetRecvTransformEvent, ToPlayersEvent};
 use de_objects::EXCLUSION_OFFSET;
 use de_types::projection::ToAltitude;
 
@@ -19,13 +22,18 @@ impl Plugin for MovementPlugin {
     fn build(&self, app: &mut App) {
         app.add_systems(
             PreMovement,
-            setup_entities.run_if(in_state(AppState::InGame)),
+            (setup_entities, setup_local).run_if(in_state(AppState::InGame)),
         )
         .add_systems(
             Movement,
-            update_transform
-                .run_if(in_state(GameState::Playing))
-                .in_set(MovementSet::UpdateTransform),
+            (
+                update_transform.in_set(MovementSet::UpdateTransform),
+                receive_remote_updates
+                    .run_if(on_event::<NetRecvTransformEvent>())
+                    .after(update_transform),
+                send_remote_updates.after(update_transform),
+            )
+                .run_if(in_state(GameState::Playing)),
         );
     }
 }
@@ -147,6 +155,79 @@ fn update_transform(
     }
 }
 
+// TODO move this?
+// TODO add these
+#[derive(Component)]
+struct TransformSync(Duration);
+
+impl TransformSync {
+    fn new() -> Self {
+        Self(Duration::ZERO)
+    }
+
+    // TODO docs
+    fn refresh(&mut self, time: Duration) {
+        // TODO constant
+        self.0 = time + Duration::from_secs(2) + Duration::from_millis(fastrand::u64(0..1_000));
+    }
+
+    fn outdated(&self, time: Duration) -> bool {
+        time >= self.0
+    }
+}
+
+// TODO rename
+fn setup_local(
+    mut commands: Commands,
+    config: Res<GameConfig>,
+    entities: Query<Entity, (With<MovableSolid>, With<Local>, Without<TransformSync>)>,
+) {
+    // TODO move to system conditions
+    if !config.multiplayer() {
+        return;
+    }
+
+    for entity in entities.iter() {
+        commands.entity(entity).insert(TransformSync::new());
+    }
+}
+
+fn receive_remote_updates(
+    mut entities: Query<&mut Transform>,
+    mut events: EventReader<NetRecvTransformEvent>,
+) {
+    for event in events.iter() {
+        if let Ok(mut transform) = entities.get_mut(event.entity()) {
+            *transform = event.transform();
+        }
+    }
+}
+
+fn send_remote_updates(
+    time: Res<Time>,
+    config: Res<GameConfig>,
+    net_entities: NetEntities,
+    mut entities: Query<(Entity, &mut TransformSync, &Transform)>,
+    mut net_events: EventWriter<ToPlayersEvent>,
+) {
+    // TODO move to system conditions
+    if !config.multiplayer() {
+        return;
+    }
+
+    let time = time.elapsed();
+    for (entity, mut sync, tranform) in entities.iter_mut() {
+        if sync.outdated(time) {
+            sync.refresh(time);
+        }
+
+        net_events.send(ToPlayersEvent::new(ToPlayers::Transform {
+            entity: net_entities.local_net_id(entity),
+            transform: tranform.into(),
+        }));
+    }
+}
+
 fn clamp(bounds: &MapBounds, translation: Vec3) -> Vec3 {
     let offset = Vec2::splat(EXCLUSION_OFFSET);
     let a = (bounds.min() + offset).to_msl();
diff --git a/crates/multiplayer/src/lib.rs b/crates/multiplayer/src/lib.rs
index ba943acf0..2d6b989d4 100644
--- a/crates/multiplayer/src/lib.rs
+++ b/crates/multiplayer/src/lib.rs
@@ -25,7 +25,7 @@ pub use crate::{
     netstate::NetState,
     playermsg::{
         GameNetSet, NetEntities, NetEntityCommands, NetRecvDespawnActiveEvent, NetRecvHealthEvent,
-        NetRecvSpawnActiveEvent,
+        NetRecvSpawnActiveEvent, NetRecvTransformEvent,
     },
 };
 use crate::{netstate::NetStatePlugin, network::NetworkPlugin};
diff --git a/crates/multiplayer/src/playermsg.rs b/crates/multiplayer/src/playermsg.rs
index 77ecb0304..9664c3253 100644
--- a/crates/multiplayer/src/playermsg.rs
+++ b/crates/multiplayer/src/playermsg.rs
@@ -17,6 +17,7 @@ impl Plugin for PlayerMsgPlugin {
         app.add_event::<NetRecvSpawnActiveEvent>()
             .add_event::<NetRecvDespawnActiveEvent>()
             .add_event::<NetRecvHealthEvent>()
+            .add_event::<NetRecvTransformEvent>()
             .add_systems(OnEnter(AppState::InGame), setup)
             .add_systems(OnExit(AppState::InGame), cleanup)
             .add_systems(
@@ -124,6 +125,26 @@ impl NetRecvHealthEvent {
     }
 }
 
+#[derive(Event)]
+pub struct NetRecvTransformEvent {
+    entity: Entity,
+    transform: Transform,
+}
+
+impl NetRecvTransformEvent {
+    fn new(entity: Entity, transform: Transform) -> Self {
+        Self { entity, transform }
+    }
+
+    pub fn entity(&self) -> Entity {
+        self.entity
+    }
+
+    pub fn transform(&self) -> Transform {
+        self.transform
+    }
+}
+
 #[derive(SystemParam)]
 pub struct NetEntities<'w> {
     config: Res<'w, GameConfig>,
@@ -305,6 +326,7 @@ fn recv_messages(
     mut inputs: EventReader<FromPlayersEvent>,
     mut spawn_events: EventWriter<NetRecvSpawnActiveEvent>,
     mut despawn_events: EventWriter<NetRecvDespawnActiveEvent>,
+    mut transform_events: EventWriter<NetRecvTransformEvent>,
     mut health_events: EventWriter<NetRecvHealthEvent>,
 ) {
     for input in inputs.iter() {
@@ -329,6 +351,11 @@ fn recv_messages(
                 let local = net_commands.deregister(*entity);
                 despawn_events.send(NetRecvDespawnActiveEvent::new(local));
             }
+            ToPlayers::Transform { entity, transform } => {
+                if let Some(local) = net_commands.local_id(*entity) {
+                    transform_events.send(NetRecvTransformEvent::new(local, transform.into()));
+                }
+            }
             ToPlayers::ChangeHealth { entity, delta } => {
                 let Some(local) = net_commands.local_id(*entity) else {
                     warn!("Received net health update of unrecognized entity: {entity:?}");