1 files changed, 40 insertions, 0 deletions
diff --git a/VRCSDK3AvatarsLegacy/Assets/VRCSDK/Dependencies/VRChat/Editor/FixConstraintUpdateOrder.cs b/VRCSDK3AvatarsLegacy/Assets/VRCSDK/Dependencies/VRChat/Editor/FixConstraintUpdateOrder.cs
new file mode 100644
index 00000000..6735702b
--- /dev/null
+++ b/VRCSDK3AvatarsLegacy/Assets/VRCSDK/Dependencies/VRChat/Editor/FixConstraintUpdateOrder.cs
@@ -0,0 +1,40 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using UnityEngine;
+using UnityEngine.LowLevel;
+using UnityEngine.PlayerLoop;
+
+namespace VRC.SDKBase.Editor
+{
+#if !VRC_CLIENT
+    public static class FixConstraintUpdateOrder
+    {
+        [RuntimeInitializeOnLoadMethod]
+        private static void ApplyFix()
+        {
+            PlayerLoopSystem currentPlayerLoopSystem = PlayerLoop.GetCurrentPlayerLoop();
+
+            // Search the current PlayerLoopSystem's sub-systems for the PreLateUpdate system.
+            PlayerLoopSystem[] playerLoopSystems = currentPlayerLoopSystem.subSystemList;
+            int preLateUpdateSystemIndex = Array.FindIndex(playerLoopSystems, system => system.type == typeof(PreLateUpdate));
+            PlayerLoopSystem preLateUpdateSystem = playerLoopSystems[preLateUpdateSystemIndex];
+
+            // Search the PreLateUpdate system's sub-systems for ScriptRunBehaviourLateUpdate and ConstraintManagerUpdate.
+            List<PlayerLoopSystem> preLateUpdateSystemSubSystems = preLateUpdateSystem.subSystemList.ToList();
+            PlayerLoopSystem scriptRunBehaviourLateUpdateSystem = preLateUpdateSystemSubSystems.Find(system => system.type == typeof(PreLateUpdate.ScriptRunBehaviourLateUpdate));
+            PlayerLoopSystem constraintManagerUpdateSystem = preLateUpdateSystemSubSystems.Find(system => system.type == typeof(PreLateUpdate.ConstraintManagerUpdate));
+
+            // Move ScriptRunBehaviourLateUpdate to before ConstraintManagerUpdate.
+            preLateUpdateSystemSubSystems.Remove(scriptRunBehaviourLateUpdateSystem);
+            preLateUpdateSystemSubSystems.Insert(preLateUpdateSystemSubSystems.IndexOf(constraintManagerUpdateSystem), scriptRunBehaviourLateUpdateSystem);
+
+            // Update the PlayerLoopSystem structs.
+            preLateUpdateSystem.subSystemList = preLateUpdateSystemSubSystems.ToArray();
+            playerLoopSystems[preLateUpdateSystemIndex] = preLateUpdateSystem;
+            currentPlayerLoopSystem.subSystemList = playerLoopSystems;
+            PlayerLoop.SetPlayerLoop(currentPlayerLoopSystem);
+        }
+    }
+#endif
+}