From 647ab23c3357e423435ee1441ecad40cf9999e8d Mon Sep 17 00:00:00 2001
From: mix <167040362+mixiate@users.noreply.github.com>
Date: Mon, 17 Mar 2025 19:39:28 +0000
Subject: [PATCH] Fix #18309: Vehicles glitch going inverted to uninverted with
 uncap fps (#24011)

---
 distribution/changelog.txt    |  1 +
 src/openrct2/ride/Vehicle.cpp | 11 +++++++++++
 2 files changed, 12 insertions(+)

diff --git a/distribution/changelog.txt b/distribution/changelog.txt
index ed66ba630f..bf0bb67fb1 100644
--- a/distribution/changelog.txt
+++ b/distribution/changelog.txt
@@ -8,6 +8,7 @@
 - Fix: [#5281] Missing supports on miniature railways built backwards.
 - Fix: [#10379] Banners outside the park can be renamed and modified (original bug).
 - Fix: [#10582] Low clearance tunnels below water are drawn incorrectly (original bug).
+- Fix: [#18309] Flying and Multi Dimension trains glitch when changing between inverted and uninverted track when uncap fps is on.
 - Fix: [#23486] Object selection minimum requirements can be bypassed with close window hotkey.
 - Fix: [#23743] Parks with guest goals over 32767 do not appear in the scenario list.
 - Fix: [#23844] Sound effects keep playing when loading another save.
diff --git a/src/openrct2/ride/Vehicle.cpp b/src/openrct2/ride/Vehicle.cpp
index 5b2120d6fe..4a05b51f36 100644
--- a/src/openrct2/ride/Vehicle.cpp
+++ b/src/openrct2/ride/Vehicle.cpp
@@ -26,6 +26,7 @@
 #include "../core/Speed.hpp"
 #include "../entity/EntityList.h"
 #include "../entity/EntityRegistry.h"
+#include "../entity/EntityTweener.h"
 #include "../entity/Particle.h"
 #include "../entity/Yaw.hpp"
 #include "../interface/Viewport.h"
@@ -7004,6 +7005,7 @@ bool Vehicle::UpdateTrackMotionForwardsGetNewTrack(
         }
 
         // Update VehicleFlags::CarIsInverted flag
+        const auto previousCarIsInverted = HasFlag(VehicleFlags::CarIsInverted);
         ClearFlag(VehicleFlags::CarIsInverted);
         {
             auto rideType = ::GetRide(tileElement->AsTrack()->GetRideIndex())->type;
@@ -7014,6 +7016,10 @@ bool Vehicle::UpdateTrackMotionForwardsGetNewTrack(
                     SetFlag(VehicleFlags::CarIsInverted);
                 }
             }
+            if (previousCarIsInverted != HasFlag(VehicleFlags::CarIsInverted))
+            {
+                EntityTweener::Get().RemoveEntity(this);
+            }
         }
     }
 
@@ -7393,6 +7399,7 @@ bool Vehicle::UpdateTrackMotionBackwardsGetNewTrack(TrackElemType trackType, con
         }
 
         // Update VehicleFlags::CarIsInverted
+        const auto previousCarIsInverted = HasFlag(VehicleFlags::CarIsInverted);
         ClearFlag(VehicleFlags::CarIsInverted);
         if (GetRideTypeDescriptor(curRide.type).HasFlag(RtdFlag::hasInvertedVariant))
         {
@@ -7400,6 +7407,10 @@ bool Vehicle::UpdateTrackMotionBackwardsGetNewTrack(TrackElemType trackType, con
             {
                 SetFlag(VehicleFlags::CarIsInverted);
             }
+            if (previousCarIsInverted != HasFlag(VehicleFlags::CarIsInverted))
+            {
+                EntityTweener::Get().RemoveEntity(this);
+            }
         }
 
         trackPos = { trackBeginEnd.begin_x, trackBeginEnd.begin_y, trackBeginEnd.begin_z };