Fix EntityMovementSystem (accidentally early exited loop whenever a l…

…erping entity was reached, causing subsequent entities to never get updated)

Sources/Core/Sources/ECS/Components/EntityLerpState.swift

@@ -1,7 +1,7 @@
-import Foundation
 import CoreFoundation
 import FirebladeECS
 import FirebladeMath
+import Foundation
 
 /// A component storing the lerp (if any) that an entity is currently undergoing; lerp is short
 /// for linear interpolation.
@@ -46,8 +46,17 @@ public class EntityLerpState: Component {
 
   /// Ticks an entities current lerp returning the entity's new position, pitch, and yaw. If there's no current
   /// lerp, then `nil` is returned.
-  public func tick(position: Vec3d, pitch: Float, yaw: Float) -> (position: Vec3d, pitch: Float, yaw: Float)? {
-    guard var lerp = currentLerp else {
+  public func tick(
+    position: Vec3d,
+    pitch: Float,
+    yaw: Float
+  ) -> (
+    position: Vec3d,
+    pitch: Float,
+    yaw: Float
+  )? {
+    guard var lerp = currentLerp, lerp.ticksRemaining > 0 else {
+      currentLerp = nil
       return nil
     }
 
@@ -60,10 +69,19 @@ public class EntityLerpState: Component {
       currentLerp = lerp
     }
 
+    let targetYaw: Float
+    if yaw - lerp.targetYaw > .pi {
+      targetYaw = lerp.targetYaw + 2 * .pi
+    } else if yaw - lerp.targetYaw < -.pi {
+      targetYaw = lerp.targetYaw - 2 * .pi
+    } else {
+      targetYaw = lerp.targetYaw
+    }
+
     return (
       MathUtil.lerp(from: position, to: lerp.targetPosition, progress: progress),
       MathUtil.lerp(from: pitch, to: lerp.targetPitch, progress: Float(progress)),
-      MathUtil.lerp(from: yaw, to: lerp.targetYaw, progress: Float(progress))
+      MathUtil.lerp(from: yaw, to: targetYaw, progress: Float(progress))
     )
   }
 }

Sources/Core/Sources/ECS/Systems/EntityMovementSystem.swift

@@ -1,7 +1,8 @@
 import FirebladeECS
 
 /// Updates the position of each entity according to its velocity (excluding the player,
-/// because velocity for the player is handled by the ``PlayerVelocitySystem-30ewl``).
+/// because velocity for the player is handled by the ``PlayerVelocitySystem``). Also handles
+/// position/rotation lerping.
 public struct EntityMovementSystem: System {
   public func update(_ nexus: Nexus, _ world: World) {
     let physicsEntities = nexus.family(
@@ -20,11 +21,13 @@ public struct EntityMovementSystem: System {
         continue
       }
 
-      if let (newPosition, newPitch, newYaw) = lerpState.tick(position: position.vector, pitch: rotation.pitch, yaw: rotation.yaw) {
+      if let (newPosition, newPitch, newYaw) = lerpState.tick(
+        position: position.vector, pitch: rotation.pitch, yaw: rotation.yaw)
+      {
         position.vector = newPosition
         rotation.pitch = newPitch
         rotation.yaw = newYaw
-        return
+        continue
       }
 
       velocity.vector *= 0.98

Sources/Core/Sources/Game.swift

@@ -102,7 +102,8 @@ public final class Game: @unchecked Sendable {
     //   together for the specific case of PlayerInputSystem); proper resource pack propagation
     //   will probably take quite a bit of work.
     tickScheduler.addSystem(
-      PlayerInputSystem(connection, self, eventBus, configuration, font, locale))
+      PlayerInputSystem(connection, self, eventBus, configuration, font, locale)
+    )
     tickScheduler.addSystem(PlayerFlightSystem())
     tickScheduler.addSystem(PlayerAccelerationSystem())
     tickScheduler.addSystem(PlayerJumpSystem())

Sources/Core/Sources/Network/Protocol/Packets/Play/Clientbound/EntityPositionPacket.swift

@@ -1,5 +1,5 @@
-import Foundation
 import FirebladeMath
+import Foundation
 
 public struct EntityPositionPacket: ClientboundEntityPacket {
   public static let id: Int = 0x28
@@ -39,6 +39,9 @@ public struct EntityPositionPacket: ClientboundEntityPacket {
         let kind = entity.get(component: EntityKindId.self)?.entityKind,
         let onGroundComponent = entity.get(component: EntityOnGround.self)
       else {
+        log.warning(
+          "Entity '\(entityId)' is missing required components to handle EntityPositionPacket"
+        )
         return
       }
 
@@ -50,8 +53,8 @@ public struct EntityPositionPacket: ClientboundEntityPacket {
       onGroundComponent.onGround = onGround
       lerpState.lerp(
         to: currentTargetPosition + relativePosition,
-        pitch: rotation.pitch,
-        yaw: rotation.yaw,
+        pitch: lerpState.currentLerp?.targetPitch ?? rotation.pitch,
+        yaw: lerpState.currentLerp?.targetYaw ?? rotation.yaw,
         duration: kind.defaultLerpDuration
       )
     }

Sources/Core/Sources/Network/Protocol/Packets/Play/Clientbound/EntityVelocityPacket.swift

@@ -23,7 +23,7 @@ public struct EntityVelocityPacket: ClientboundEntityPacket {
     ) { velocityComponent in
       // TODO: Figure out why handling velocity is causing entities to drift (observe spiders for a while
       //   to reproduce issue). Works best if spider is trying to climb a wall but it stuck under a roof.
-      // velocityComponent.vector = velocity
+      velocityComponent.vector = velocity
     }
   }
 }

Sources/Core/Sources/Network/Protocol/Packets/Play/Clientbound/SpawnEntityPacket.swift

@@ -1,6 +1,6 @@
-import Foundation
 import FirebladeECS
 import FirebladeMath
+import Foundation
 
 public struct SpawnEntityPacket: ClientboundPacket {
   public static let id: Int = 0x00

Sources/Core/Sources/Network/Protocol/Packets/Play/Clientbound/SpawnLivingEntityPacket.swift

@@ -1,5 +1,5 @@
-import Foundation
 import FirebladeMath
+import Foundation
 
 public struct SpawnLivingEntityPacket: ClientboundPacket {
   public static let id: Int = 0x02
@@ -30,7 +30,7 @@ public struct SpawnLivingEntityPacket: ClientboundPacket {
     }
 
     client.game.createEntity(id: entityId) {
-      LivingEntity() // Mark it as a living entity
+      LivingEntity()  // Mark it as a living entity
       EntityKindId(type)
       EntityId(entityId)
       EntityUUID(entityUUID)

Sources/Core/Sources/Network/Protocol/Packets/Play/Clientbound/SpawnPlayerPacket.swift

@@ -1,5 +1,5 @@
-import Foundation
 import FirebladeMath
+import Foundation
 
 public struct SpawnPlayerPacket: ClientboundPacket {
   public static let id: Int = 0x04