From cf86e0de1dbdd47e9e875d7f49dfb812014e6f27 Mon Sep 17 00:00:00 2001
From: Princess Cheeseballs <66055347+Pronana@users.noreply.github.com>
Date: Tue, 6 May 2025 06:49:43 -0700
Subject: [PATCH] Ghost friction fix (#37124)

* commit

* fix for real
---
 .../Components/FrictionContactsComponent.cs       | 15 +++++++++------
 .../Movement/Systems/FrictionContactsSystem.cs    |  9 +++++++++
 .../Movement/Systems/SharedMoverController.cs     |  3 ++-
 3 files changed, 20 insertions(+), 7 deletions(-)

diff --git a/Content.Shared/Movement/Components/FrictionContactsComponent.cs b/Content.Shared/Movement/Components/FrictionContactsComponent.cs
index 204e35a348..b6e1d533a2 100644
--- a/Content.Shared/Movement/Components/FrictionContactsComponent.cs
+++ b/Content.Shared/Movement/Components/FrictionContactsComponent.cs
@@ -8,24 +8,27 @@ namespace Content.Shared.Movement.Components;
 [Access(typeof(FrictionContactsSystem))]
 public sealed partial class FrictionContactsComponent : Component
 {
+    /// <summary>
+    /// Should this affect airborne mobs?
+    /// </summary>
+    [DataField, AutoNetworkedField]
+    public bool AffectAirborne;
+
     /// <summary>
     /// Modified mob friction while on FrictionContactsComponent
     /// </summary>
-    [DataField, ViewVariables(VVAccess.ReadWrite)]
-    [AutoNetworkedField]
+    [DataField, AutoNetworkedField]
     public float MobFriction = 0.05f;
 
     /// <summary>
     /// Modified mob friction without input while on FrictionContactsComponent
     /// </summary>
-    [AutoNetworkedField]
-    [DataField, ViewVariables(VVAccess.ReadWrite)]
+    [DataField, AutoNetworkedField]
     public float? MobFrictionNoInput = 0.05f;
 
     /// <summary>
     /// Modified mob acceleration while on FrictionContactsComponent
     /// </summary>
-    [AutoNetworkedField]
-    [DataField, ViewVariables(VVAccess.ReadWrite)]
+    [DataField, AutoNetworkedField]
     public float MobAcceleration = 0.1f;
 }
diff --git a/Content.Shared/Movement/Systems/FrictionContactsSystem.cs b/Content.Shared/Movement/Systems/FrictionContactsSystem.cs
index 4dd679c37c..09d74bfb40 100644
--- a/Content.Shared/Movement/Systems/FrictionContactsSystem.cs
+++ b/Content.Shared/Movement/Systems/FrictionContactsSystem.cs
@@ -1,3 +1,4 @@
+using Content.Shared.Gravity;
 using Content.Shared.Movement.Components;
 using Robust.Shared.Physics.Components;
 using Robust.Shared.Physics.Events;
@@ -7,6 +8,7 @@ namespace Content.Shared.Movement.Systems;
 
 public sealed class FrictionContactsSystem : EntitySystem
 {
+    [Dependency] private readonly SharedGravitySystem _gravity = default!;
     [Dependency] private readonly SharedPhysicsSystem _physics = default!;
     [Dependency] private readonly MovementSpeedModifierSystem _speedModifierSystem = default!;
 
@@ -82,12 +84,19 @@ public sealed class FrictionContactsSystem : EntitySystem
         var frictionNoInput = 0.0f;
         var acceleration = 0.0f;
 
+        var isAirborne = physicsComponent.BodyStatus == BodyStatus.InAir || _gravity.IsWeightless(entity, physicsComponent);
+
         var remove = true;
         var entries = 0;
         foreach (var ent in _physics.GetContactingEntities(entity, physicsComponent))
         {
             if (!TryComp<FrictionContactsComponent>(ent, out var contacts))
                 continue;
+
+            // Entities that are airborne should not be affected by contact slowdowns that are specified to not affect airborne entities.
+            if (isAirborne && !contacts.AffectAirborne)
+                continue;
+
             friction += contacts.MobFriction;
             frictionNoInput += contacts.MobFrictionNoInput ?? contacts.MobFriction;
             acceleration += contacts.MobAcceleration;
diff --git a/Content.Shared/Movement/Systems/SharedMoverController.cs b/Content.Shared/Movement/Systems/SharedMoverController.cs
index d8aacb7480..d800234a6d 100644
--- a/Content.Shared/Movement/Systems/SharedMoverController.cs
+++ b/Content.Shared/Movement/Systems/SharedMoverController.cs
@@ -260,7 +260,8 @@ public abstract partial class SharedMoverController : VirtualController
         else
         {
             if (MapGridQuery.TryComp(xform.GridUid, out var gridComp)
-                && _mapSystem.TryGetTileRef(xform.GridUid.Value, gridComp, xform.Coordinates, out var tile))
+                && _mapSystem.TryGetTileRef(xform.GridUid.Value, gridComp, xform.Coordinates, out var tile)
+                && physicsComponent.BodyStatus == BodyStatus.OnGround)
                 tileDef = (ContentTileDefinition) _tileDefinitionManager[tile.Tile.TypeId];
 
             var walkSpeed = moveSpeedComponent?.CurrentWalkSpeed ?? MovementSpeedModifierComponent.DefaultBaseWalkSpeed;
-- 
2.51.2