From 5ade8c2695e56a7cc1b3b30e05f146d603000e3f Mon Sep 17 00:00:00 2001
From: metalgearsloth <31366439+metalgearsloth@users.noreply.github.com>
Date: Thu, 2 Sep 2021 12:35:16 +1000
Subject: [PATCH] Fix pulling lerping (#4550)

---
 .../Physics/Controllers/MoverController.cs    | 27 +++++++++++++++++++
 .../EntitySystems/SharedMoverSystem.cs        |  3 ++-
 .../Movement/SharedMoverController.cs         |  2 ++
 3 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/Content.Client/Physics/Controllers/MoverController.cs b/Content.Client/Physics/Controllers/MoverController.cs
index 9b53311e91..77148fec6d 100644
--- a/Content.Client/Physics/Controllers/MoverController.cs
+++ b/Content.Client/Physics/Controllers/MoverController.cs
@@ -1,5 +1,8 @@
+using Content.Shared.Body.Components;
+using Content.Shared.MobState;
 using Content.Shared.Movement;
 using Content.Shared.Movement.Components;
+using Content.Shared.Pulling.Components;
 using Robust.Client.Player;
 using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
@@ -32,6 +35,30 @@ namespace Content.Client.Physics.Controllers
                 joint.BodyB.Predict = true;
             }
 
+            // If we're being pulled then we won't predict anything and will receive server lerps so it looks way smoother.
+            if (player.TryGetComponent(out SharedPullableComponent? pullableComp))
+            {
+                var puller = pullableComp.Puller;
+                if (puller != null && puller.TryGetComponent<PhysicsComponent>(out var pullerBody))
+                {
+                    pullerBody.Predict = false;
+                    body.Predict = false;
+                }
+            }
+
+            // If we're pulling a mob then make sure that isn't predicted so it doesn't fuck our velocity up.
+            if (player.TryGetComponent(out SharedPullerComponent? pullerComp))
+            {
+                var pulling = pullerComp.Pulling;
+
+                if (pulling != null &&
+                    pulling.HasComponent<IMobStateComponent>() &&
+                    pulling.TryGetComponent(out PhysicsComponent? pullingBody))
+                {
+                    pullingBody.Predict = false;
+                }
+            }
+
             // Server-side should just be handled on its own so we'll just do this shizznit
             if (player.TryGetComponent(out IMobMoverComponent? mobMover))
             {
diff --git a/Content.Shared/Movement/EntitySystems/SharedMoverSystem.cs b/Content.Shared/Movement/EntitySystems/SharedMoverSystem.cs
index f722531c91..9ab8e4a474 100644
--- a/Content.Shared/Movement/EntitySystems/SharedMoverSystem.cs
+++ b/Content.Shared/Movement/EntitySystems/SharedMoverSystem.cs
@@ -1,4 +1,5 @@
 using System.Diagnostics.CodeAnalysis;
+using System.Linq;
 using Content.Shared.MobState;
 using Content.Shared.Movement.Components;
 using Robust.Shared.Containers;
@@ -49,7 +50,7 @@ namespace Content.Shared.Movement.EntitySystems
 
             if (owner != null && session != null)
             {
-                foreach (var comp in owner.GetAllComponents<IRelayMoveInput>())
+                foreach (var comp in owner.GetAllComponents<IRelayMoveInput>().ToArray())
                 {
                     comp.MoveInputPressed(session);
                 }
diff --git a/Content.Shared/Movement/SharedMoverController.cs b/Content.Shared/Movement/SharedMoverController.cs
index 6d4f5666f5..d6dadc28d1 100644
--- a/Content.Shared/Movement/SharedMoverController.cs
+++ b/Content.Shared/Movement/SharedMoverController.cs
@@ -152,6 +152,8 @@ namespace Content.Shared.Movement
         {
             return body.BodyStatus == BodyStatus.OnGround &&
                    body.Owner.HasComponent<IMobStateComponent>() &&
+                   // If we're being pulled then don't mess with our velocity.
+                   (!body.Owner.TryGetComponent(out SharedPullableComponent? pullable) || !pullable.BeingPulled) &&
                    _blocker.CanMove(body.Owner);
         }