Core/Transports: Path generation rewrite v2

* No TaxiPathNode row is skipped anymore (events/delays on first node now work)
* Fixed transport animation synchronization with client
* Fixed stoppable transports randomly resuming their path after relogging

Closes #27985

2 files changed, 379 insertions, 249 deletions

diff --git a/src/server/game/Maps/TransportMgr.cpp b/src/server/game/Maps/TransportMgr.cpp
index 5bcd0db73b0..3c8fcc3498a 100644
--- a/src/server/game/Maps/TransportMgr.cpp
+++ b/src/server/game/Maps/TransportMgr.cpp
@@ -29,12 +29,146 @@
 #include "Spline.h"
 #include "Transport.h"
 
-bool KeyFrame::IsStopFrame() const
+TransportPathLeg::TransportPathLeg() = default;
+TransportPathLeg::~TransportPathLeg() = default;
+TransportPathLeg::TransportPathLeg(TransportPathLeg&&) noexcept = default;
+TransportPathLeg& TransportPathLeg::operator=(TransportPathLeg&&) noexcept = default;
+
+TransportTemplate::TransportTemplate() = default;
+TransportTemplate::~TransportTemplate() = default;
+TransportTemplate::TransportTemplate(TransportTemplate&&) noexcept = default;
+TransportTemplate& TransportTemplate::operator=(TransportTemplate&&) noexcept = default;
+
+Optional<Position> TransportTemplate::ComputePosition(uint32 time, TransportMovementState* moveState, size_t* legIndex) const
 {
-    return (Node->Flags & TAXI_PATH_NODE_FLAG_STOP) != 0;
+    time %= TotalPathTime;
+
+    // find leg
+    auto legItr = PathLegs.begin();
+    while (legItr->StartTimestamp + legItr->Duration <= time)
+    {
+        ++legItr;
+
+        if (legItr == PathLegs.end())
+            return {};
+    }
+
+    // find segment
+    uint32 prevSegmentTime = legItr->StartTimestamp;
+    auto segmentItr = legItr->Segments.begin();
+    double distanceMoved = 0.0;
+    bool isOnPause = false;
+    for (; segmentItr != std::prev(legItr->Segments.end()); ++segmentItr)
+    {
+        if (time < segmentItr->SegmentEndArrivalTimestamp)
+            break;
+
+        distanceMoved = segmentItr->DistanceFromLegStartAtEnd;
+        if (time < segmentItr->SegmentEndArrivalTimestamp + segmentItr->Delay)
+        {
+            isOnPause = true;
+            break;
+        }
+
+        prevSegmentTime = segmentItr->SegmentEndArrivalTimestamp + segmentItr->Delay;
+    }
+
+    if (!isOnPause)
+        distanceMoved += CalculateDistanceMoved(
+            double(time - prevSegmentTime) * 0.001,
+            double(segmentItr->SegmentEndArrivalTimestamp - prevSegmentTime) * 0.001,
+            segmentItr == legItr->Segments.begin(),
+            segmentItr == std::prev(legItr->Segments.end()));
+
+    Movement::SplineBase::index_type splineIndex;
+    float splinePointProgress;
+    legItr->Spline->computeIndex(std::fmin(distanceMoved / legItr->Spline->length(), 1.0), splineIndex, splinePointProgress);
+
+    G3D::Vector3 pos, dir;
+    legItr->Spline->evaluate_percent(splineIndex, splinePointProgress, pos);
+    legItr->Spline->evaluate_derivative(splineIndex, splinePointProgress, dir);
+
+    if (moveState)
+        *moveState = isOnPause ? TransportMovementState::WaitingOnPauseWaypoint : TransportMovementState::Moving;
+
+    if (legIndex)
+        *legIndex = std::distance(PathLegs.begin(), legItr);
+
+    return Position(pos.x, pos.y, pos.z, std::atan2(dir.y, dir.x) + float(M_PI));
 }
 
-TransportTemplate::~TransportTemplate() = default;
+double TransportTemplate::CalculateDistanceMoved(double timePassedInSegment, double segmentDuration, bool isFirstSegment, bool isLastSegment) const
+{
+    if (isFirstSegment)
+    {
+        if (!isLastSegment)
+        {
+            double accelerationTime = std::fmin(AccelerationTime, segmentDuration);
+            double segmentTimeAtFullSpeed = segmentDuration - accelerationTime;
+            if (timePassedInSegment <= segmentTimeAtFullSpeed)
+            {
+                return timePassedInSegment * Speed;
+            }
+            else
+            {
+                double segmentAccelerationTime = timePassedInSegment - segmentTimeAtFullSpeed;
+                double segmentAccelerationDistance = AccelerationRate * accelerationTime;
+                double segmentDistanceAtFullSpeed = segmentTimeAtFullSpeed * Speed;
+                return (2.0 * segmentAccelerationDistance - segmentAccelerationTime * AccelerationRate) * 0.5 * segmentAccelerationTime + segmentDistanceAtFullSpeed;
+            }
+        }
+
+        return timePassedInSegment * Speed;
+    }
+
+    if (isLastSegment)
+    {
+        if (!isFirstSegment)
+        {
+            if (timePassedInSegment <= std::fmin(AccelerationTime, segmentDuration))
+                return AccelerationRate * timePassedInSegment * 0.5 * timePassedInSegment;
+            else
+                return (timePassedInSegment - AccelerationTime) * Speed + AccelerationDistance;
+        }
+
+        return timePassedInSegment * Speed;
+    }
+
+    double accelerationTime = std::fmin(segmentDuration * 0.5, AccelerationTime);
+    if (timePassedInSegment <= segmentDuration - accelerationTime)
+    {
+        if (timePassedInSegment <= accelerationTime)
+            return AccelerationRate * timePassedInSegment * 0.5 * timePassedInSegment;
+        else
+            return (timePassedInSegment - AccelerationTime) * Speed + AccelerationDistance;
+    }
+    else
+    {
+        double segmentTimeSpentAccelerating = timePassedInSegment - (segmentDuration - accelerationTime);
+        return (segmentDuration - 2 * accelerationTime) * Speed
+            + AccelerationRate * accelerationTime * 0.5 * accelerationTime
+            + (2.0 * AccelerationRate * accelerationTime - segmentTimeSpentAccelerating * AccelerationRate) * 0.5 * segmentTimeSpentAccelerating;
+    }
+}
+
+uint32 TransportTemplate::GetNextPauseWaypointTimestamp(uint32 time) const
+{
+    auto legItr = PathLegs.begin();
+    while (legItr->StartTimestamp + legItr->Duration <= time)
+    {
+        ++legItr;
+
+        if (legItr == PathLegs.end())
+            return time;
+    }
+
+    auto segmentItr = legItr->Segments.begin();
+    for (; segmentItr != std::prev(legItr->Segments.end()); ++segmentItr)
+        if (time < segmentItr->SegmentEndArrivalTimestamp + segmentItr->Delay)
+            break;
+
+    return segmentItr->SegmentEndArrivalTimestamp + segmentItr->Delay;
+}
 
 TransportMgr::TransportMgr() = default;
 
@@ -87,12 +221,14 @@ void TransportMgr::LoadTransportTemplates()
 
         // paths are generated per template, saves us from generating it again in case of instanced transports
         TransportTemplate& transport = _transportTemplates[entry];
-        transport.entry = entry;
-        GeneratePath(goInfo, &transport);
+
+        std::set<uint32> mapsUsed;
+
+        GeneratePath(goInfo, &transport, &mapsUsed);
 
         // transports in instance are only on one map
-        if (transport.inInstance)
-            _instanceTransports[*transport.mapsUsed.begin()].insert(entry);
+        if (transport.InInstance)
+            _instanceTransports[*mapsUsed.begin()].insert(entry);
 
         ++count;
     } while (result->NextRow());
@@ -203,239 +339,206 @@ public:
     Movement::PointsArray& _points;
 };
 
-void TransportMgr::GeneratePath(GameObjectTemplate const* goInfo, TransportTemplate* transport)
+static void InitializeLeg(TransportPathLeg* leg, std::vector<TransportPathEvent>* outEvents, std::vector<TaxiPathNodeEntry const*> const& pathPoints, std::vector<TaxiPathNodeEntry const*> const& pauses,
+    std::vector<TaxiPathNodeEntry const*> const& events, GameObjectTemplate const* goInfo, uint32& totalTime)
 {
-    uint32 pathId = goInfo->moTransport.taxiPathID;
-    TaxiPathNodeList const& path = sTaxiPathNodesByPath[pathId];
-    std::vector<KeyFrame>& keyFrames = transport->keyFrames;
-    Movement::PointsArray splinePath, allPoints;
-    bool mapChange = false;
-    for (size_t i = 0; i < path.size(); ++i)
-        allPoints.push_back(G3D::Vector3(path[i]->Loc.X, path[i]->Loc.Y, path[i]->Loc.Z));
-
-    // Add extra points to allow derivative calculations for all path nodes
-    allPoints.insert(allPoints.begin(), allPoints.front().lerp(allPoints[1], -0.2f));
-    allPoints.push_back(allPoints.back().lerp(allPoints[allPoints.size() - 2], -0.2f));
-    allPoints.push_back(allPoints.back().lerp(allPoints[allPoints.size() - 2], -1.0f));
-
-    SplineRawInitializer initer(allPoints);
-    TransportSpline orientationSpline;
-    orientationSpline.init_spline_custom(initer);
-    orientationSpline.initLengths();
-
-    for (size_t i = 0; i < path.size(); ++i)
+    Movement::PointsArray splinePath;
+    std::transform(pathPoints.begin(), pathPoints.end(), std::back_inserter(splinePath), [](TaxiPathNodeEntry const* node) { return Movement::Vector3(node->Loc.X, node->Loc.Y, node->Loc.Z); });
+    SplineRawInitializer initer(splinePath);
+    leg->Spline = std::make_unique<TransportSpline>();
+    leg->Spline->set_steps_per_segment(20);
+    leg->Spline->init_spline_custom(initer);
+    leg->Spline->initLengths();
+
+    leg->Segments.resize(pauses.size() + 1);
+
+    auto legTimeAccelDecel = [&](double dist)
     {
-        if (!mapChange)
-        {
-            TaxiPathNodeEntry const* node_i = path[i];
-            if (i != path.size() - 1 && (node_i->Flags & TAXI_PATH_NODE_FLAG_TELEPORT || node_i->ContinentID != path[i + 1]->ContinentID))
-            {
-                keyFrames.back().Teleport = true;
-                mapChange = true;
-            }
-            else
-            {
-                KeyFrame k(node_i);
-                G3D::Vector3 h;
-                orientationSpline.evaluate_derivative(i + 1, 0.0f, h);
-                k.InitialOrientation = Position::NormalizeOrientation(std::atan2(h.y, h.x) + float(M_PI));
-
-                keyFrames.push_back(k);
-                splinePath.push_back(G3D::Vector3(node_i->Loc.X, node_i->Loc.Y, node_i->Loc.Z));
-                transport->mapsUsed.insert(k.Node->ContinentID);
-            }
-        }
+        double speed = double(goInfo->moTransport.moveSpeed);
+        double accel = double(goInfo->moTransport.accelRate);
+        double accelDist = 0.5 * speed * speed / accel;
+        if (accelDist >= dist * 0.5)
+            return uint32(std::sqrt(dist / accel) * 2000.0);
         else
-            mapChange = false;
-    }
+            return uint32((dist - (accelDist + accelDist)) / speed * 1000.0 + speed / accel * 2000.0);
+    };
 
-    if (splinePath.size() >= 2)
+    auto legTimeAccel = [&](double dist)
     {
-        // Remove special catmull-rom spline points
-        if (!keyFrames.front().IsStopFrame() && !keyFrames.front().Node->ArrivalEventID && !keyFrames.front().Node->DepartureEventID)
-        {
-            splinePath.erase(splinePath.begin());
-            keyFrames.erase(keyFrames.begin());
-        }
-        if (!keyFrames.back().IsStopFrame() && !keyFrames.back().Node->ArrivalEventID && !keyFrames.back().Node->DepartureEventID)
-        {
-            splinePath.pop_back();
-            keyFrames.pop_back();
-        }
-    }
-
-    ASSERT(!keyFrames.empty());
-
-    if (transport->mapsUsed.size() > 1)
+        double speed = double(goInfo->moTransport.moveSpeed);
+        double accel = double(goInfo->moTransport.accelRate);
+        double accelDist = 0.5 * speed * speed / accel;
+        if (accelDist >= dist)
+            return uint32(std::sqrt((dist + dist) / accel) * 1000.0);
+        else
+            return uint32(((dist - accelDist) / speed + speed / accel) * 1000.0);
+    };
+
+    // Init segments
+    size_t pauseItr = 0;
+    size_t eventItr = 0;
+    double splineLengthToPreviousNode = 0.0;
+    uint32 delaySum = 0;
+    if (!pauses.empty())
     {
-        for (std::set<uint32>::const_iterator itr = transport->mapsUsed.begin(); itr != transport->mapsUsed.end(); ++itr)
-            ASSERT(!sMapStore.LookupEntry(*itr)->Instanceable());
+        for (; pauseItr < pauses.size(); ++pauseItr)
+        {
+            auto pausePointItr = std::find(pathPoints.begin(), pathPoints.end(), pauses[pauseItr]);
+            if (*pausePointItr == pathPoints.back()) // last point is a "fake" spline point, its position can never be reached so transport cannot stop there
+                break;
 
-        transport->inInstance = false;
-    }
-    else
-        transport->inInstance = sMapStore.LookupEntry(*transport->mapsUsed.begin())->Instanceable();
+            for (; eventItr < events.size(); ++eventItr)
+            {
+                auto eventPointItr = std::find(pathPoints.begin(), pathPoints.end(), events[eventItr]);
+                if (eventPointItr > pausePointItr)
+                    break;
 
-    // last to first is always "teleport", even for closed paths
-    keyFrames.back().Teleport = true;
+                double length = leg->Spline->length(std::distance(pathPoints.begin(), eventPointItr)) - splineLengthToPreviousNode;
 
-    const float speed = float(goInfo->moTransport.moveSpeed);
-    const float accel = float(goInfo->moTransport.accelRate);
-    const float accel_dist = 0.5f * speed * speed / accel;
+                uint32 splineTime = 0;
+                if (pauseItr)
+                    splineTime = legTimeAccelDecel(length);
+                else
+                    splineTime = legTimeAccel(length);
 
-    transport->accelTime = speed / accel;
-    transport->accelDist = accel_dist;
+                if ((*eventPointItr)->ArrivalEventID)
+                {
+                    TransportPathEvent& event = outEvents->emplace_back();
+                    event.Timestamp = totalTime + splineTime + leg->Duration;
+                    event.EventId = (*eventPointItr)->ArrivalEventID;
+                }
 
-    int32 firstStop = -1;
-    int32 lastStop = -1;
+                if ((*eventPointItr)->DepartureEventID)
+                {
+                    TransportPathEvent& event = outEvents->emplace_back();
+                    event.Timestamp = totalTime + splineTime + leg->Duration + (pausePointItr == eventPointItr ? (*eventPointItr)->Delay * IN_MILLISECONDS : 0);
+                    event.EventId = (*eventPointItr)->DepartureEventID;
+                }
+            }
 
-    // first cell is arrived at by teleportation :S
-    keyFrames[0].DistFromPrev = 0;
-    keyFrames[0].Index = 1;
-    if (keyFrames[0].IsStopFrame())
-    {
-        firstStop = 0;
-        lastStop = 0;
+            double splineLengthToCurrentNode = leg->Spline->length(std::distance(pathPoints.begin(), pausePointItr));
+            double length = splineLengthToCurrentNode - splineLengthToPreviousNode;
+            uint32 movementTime = 0;
+            if (pauseItr)
+                movementTime = legTimeAccelDecel(length);
+            else
+                movementTime = legTimeAccel(length);
+
+            leg->Duration += movementTime;
+            leg->Segments[pauseItr].SegmentEndArrivalTimestamp = leg->Duration + delaySum;
+            leg->Segments[pauseItr].Delay = (*pausePointItr)->Delay * IN_MILLISECONDS;
+            leg->Segments[pauseItr].DistanceFromLegStartAtEnd = splineLengthToCurrentNode;
+            delaySum += (*pausePointItr)->Delay * IN_MILLISECONDS;
+            splineLengthToPreviousNode = splineLengthToCurrentNode;
+        }
     }
 
-    // find the rest of the distances between key points
-    // Every path segment has its own spline
-    size_t start = 0;
-    for (size_t i = 1; i < keyFrames.size(); ++i)
+    // Process events happening after last pause
+    for (; eventItr < events.size(); ++eventItr)
     {
-        if (keyFrames[i - 1].Teleport || i + 1 == keyFrames.size())
-        {
-            size_t extra = !keyFrames[i - 1].Teleport ? 1 : 0;
-            std::shared_ptr<TransportSpline> spline = std::make_shared<TransportSpline>();
-            spline->init_spline(&splinePath[start], i - start + extra, Movement::SplineBase::ModeCatmullrom);
-            spline->initLengths();
-            for (size_t j = start; j < i + extra; ++j)
-            {
-                keyFrames[j].Index = j - start + 1;
-                keyFrames[j].DistFromPrev = float(spline->length(j - start, j + 1 - start));
-                if (j > 0)
-                    keyFrames[j - 1].NextDistFromPrev = keyFrames[j].DistFromPrev;
-                keyFrames[j].Spline = spline;
-            }
-
-            if (keyFrames[i - 1].Teleport)
-            {
-                keyFrames[i].Index = i - start + 1;
-                keyFrames[i].DistFromPrev = 0.0f;
-                keyFrames[i - 1].NextDistFromPrev = 0.0f;
-                keyFrames[i].Spline = spline;
-            }
+        auto eventPointItr = std::find(pathPoints.begin(), pathPoints.end(), events[eventItr]);
+        if (*eventPointItr == pathPoints.back()) // last point is a "fake" spline node, events cannot happen there
+            break;
+
+        double length = leg->Spline->length(std::distance(pathPoints.begin(), eventPointItr)) - splineLengthToPreviousNode;
+        uint32 splineTime = 0;
+        if (pauseItr)
+            splineTime = legTimeAccel(length);
+        else
+            splineTime = uint32(length / double(goInfo->moTransport.moveSpeed) * 1000.0);
 
-            start = i;
+        if ((*eventPointItr)->ArrivalEventID)
+        {
+            TransportPathEvent& event = outEvents->emplace_back();
+            event.Timestamp = totalTime + splineTime + leg->Duration;
+            event.EventId = (*eventPointItr)->ArrivalEventID;
         }
 
-        if (keyFrames[i].IsStopFrame())
+        if ((*eventPointItr)->DepartureEventID)
         {
-            // remember first stop frame
-            if (firstStop == -1)
-                firstStop = i;
-            lastStop = i;
+            TransportPathEvent& event = outEvents->emplace_back();
+            event.Timestamp = totalTime + splineTime + leg->Duration;
+            event.EventId = (*eventPointItr)->DepartureEventID;
         }
     }
 
-    keyFrames.back().NextDistFromPrev = keyFrames.front().DistFromPrev;
+    // Add segment after last pause
+    double length = leg->Spline->length() - splineLengthToPreviousNode;
+    uint32 splineTime = 0;
+    if (pauseItr)
+        splineTime = legTimeAccel(length);
+    else
+        splineTime = uint32(length / double(goInfo->moTransport.moveSpeed) * 1000.0);
 
-    if (firstStop == -1 || lastStop == -1)
-        firstStop = lastStop = 0;
+    leg->StartTimestamp = totalTime;
+    leg->Duration += splineTime + delaySum;
+    leg->Segments[pauseItr].SegmentEndArrivalTimestamp = leg->Duration;
+    leg->Segments[pauseItr].Delay = 0;
+    leg->Segments[pauseItr].DistanceFromLegStartAtEnd = leg->Spline->length();
+    totalTime += leg->Segments[pauseItr].SegmentEndArrivalTimestamp + leg->Segments[pauseItr].Delay;
 
-    // at stopping keyframes, we define distSinceStop == 0,
-    // and distUntilStop is to the next stopping keyframe.
-    // this is required to properly handle cases of two stopping frames in a row (yes they do exist)
-    float tmpDist = 0.0f;
-    for (size_t i = 0; i < keyFrames.size(); ++i)
-    {
-        int32 j = (i + lastStop) % keyFrames.size();
-        if (keyFrames[j].IsStopFrame() || j == lastStop)
-            tmpDist = 0.0f;
-        else
-            tmpDist += keyFrames[j].DistFromPrev;
-        keyFrames[j].DistSinceStop = tmpDist;
-    }
+    for (TransportPathSegment& segment : leg->Segments)
+        segment.SegmentEndArrivalTimestamp += leg->StartTimestamp;
 
-    tmpDist = 0.0f;
-    for (int32 i = int32(keyFrames.size()) - 1; i >= 0; i--)
-    {
-        int32 j = (i + firstStop) % keyFrames.size();
-        tmpDist += keyFrames[(j + 1) % keyFrames.size()].DistFromPrev;
-        keyFrames[j].DistUntilStop = tmpDist;
-        if (keyFrames[j].IsStopFrame() || j == firstStop)
-            tmpDist = 0.0f;
-    }
+    if (leg->Segments.size() > pauseItr + 1)
+        leg->Segments.resize(pauseItr + 1);
+}
+
+void TransportMgr::GeneratePath(GameObjectTemplate const* goInfo, TransportTemplate* transport, std::set<uint32>* mapsUsed)
+{
+    uint32 pathId = goInfo->moTransport.taxiPathID;
+    TaxiPathNodeList const& path = sTaxiPathNodesByPath[pathId];
 
-    for (size_t i = 0; i < keyFrames.size(); ++i)
+    transport->Speed = double(goInfo->moTransport.moveSpeed);
+    transport->AccelerationRate = double(goInfo->moTransport.accelRate);
+    transport->AccelerationTime = transport->Speed / transport->AccelerationRate;
+    transport->AccelerationDistance = 0.5 * transport->Speed * transport->Speed / transport->AccelerationRate;
+
+    std::vector<TaxiPathNodeEntry const*> pathPoints;
+    std::vector<TaxiPathNodeEntry const*> pauses;
+    std::vector<TaxiPathNodeEntry const*> events;
+    TransportPathLeg* leg = &transport->PathLegs.emplace_back();
+    leg->MapId = path[0]->ContinentID;
+    bool prevNodeWasTeleport = false;
+    uint32 totalTime = 0;
+    for (TaxiPathNodeEntry const* node : path)
     {
-        float total_dist = keyFrames[i].DistSinceStop + keyFrames[i].DistUntilStop;
-        if (total_dist < 2 * accel_dist) // won't reach full speed
-        {
-            if (keyFrames[i].DistSinceStop < keyFrames[i].DistUntilStop) // is still accelerating
-            {
-                // calculate accel+brake time for this short segment
-                float segment_time = 2.0f * std::sqrt((keyFrames[i].DistUntilStop + keyFrames[i].DistSinceStop) / accel);
-                // substract acceleration time
-                keyFrames[i].TimeTo = segment_time - std::sqrt(2 * keyFrames[i].DistSinceStop / accel);
-            }
-            else // slowing down
-                keyFrames[i].TimeTo = std::sqrt(2 * keyFrames[i].DistUntilStop / accel);
-        }
-        else if (keyFrames[i].DistSinceStop < accel_dist) // still accelerating (but will reach full speed)
+        if (node->ContinentID != leg->MapId || prevNodeWasTeleport)
         {
-            // calculate accel + cruise + brake time for this long segment
-            float segment_time = (keyFrames[i].DistUntilStop + keyFrames[i].DistSinceStop) / speed + (speed / accel);
-            // substract acceleration time
-            keyFrames[i].TimeTo = segment_time - std::sqrt(2 * keyFrames[i].DistSinceStop / accel);
+            InitializeLeg(leg, &transport->Events, pathPoints, pauses, events, goInfo, totalTime);
+
+            leg = &transport->PathLegs.emplace_back();
+            leg->MapId = node->ContinentID;
+            pathPoints.clear();
+            pauses.clear();
+            events.clear();
         }
-        else if (keyFrames[i].DistUntilStop < accel_dist) // already slowing down (but reached full speed)
-            keyFrames[i].TimeTo = std::sqrt(2 * keyFrames[i].DistUntilStop / accel);
-        else // at full speed
-            keyFrames[i].TimeTo = (keyFrames[i].DistUntilStop / speed) + (0.5f * speed / accel);
-    }
 
-    // calculate tFrom times from tTo times
-    float segmentTime = 0.0f;
-    for (size_t i = 0; i < keyFrames.size(); ++i)
-    {
-        int32 j = (i + lastStop) % keyFrames.size();
-        if (keyFrames[j].IsStopFrame() || j == lastStop)
-            segmentTime = keyFrames[j].TimeTo;
-        keyFrames[j].TimeFrom = segmentTime - keyFrames[j].TimeTo;
-    }
+        prevNodeWasTeleport = (node->Flags & TAXI_PATH_NODE_FLAG_TELEPORT) != 0;
+        pathPoints.push_back(node);
+        if (node->Flags & TAXI_PATH_NODE_FLAG_STOP)
+            pauses.push_back(node);
 
-    // calculate path times
-    keyFrames[0].ArriveTime = 0;
-    float curPathTime = 0.0f;
-    if (keyFrames[0].IsStopFrame())
-    {
-        curPathTime = float(keyFrames[0].Node->Delay);
-        keyFrames[0].DepartureTime = uint32(curPathTime * IN_MILLISECONDS);
+        if (node->ArrivalEventID || node->DepartureEventID)
+            events.push_back(node);
+
+        mapsUsed->insert(node->ContinentID);
     }
 
-    for (size_t i = 1; i < keyFrames.size(); ++i)
+    if (!leg->Spline)
+        InitializeLeg(leg, &transport->Events, pathPoints, pauses, events, goInfo, totalTime);
+
+    if (mapsUsed->size() > 1)
     {
-        curPathTime += keyFrames[i - 1].TimeTo;
-        if (keyFrames[i].IsStopFrame())
-        {
-            keyFrames[i].ArriveTime = uint32(curPathTime * IN_MILLISECONDS);
-            keyFrames[i - 1].NextArriveTime = keyFrames[i].ArriveTime;
-            curPathTime += float(keyFrames[i].Node->Delay);
-            keyFrames[i].DepartureTime = uint32(curPathTime * IN_MILLISECONDS);
-        }
-        else
-        {
-            curPathTime -= keyFrames[i].TimeTo;
-            keyFrames[i].ArriveTime = uint32(curPathTime * IN_MILLISECONDS);
-            keyFrames[i - 1].NextArriveTime = keyFrames[i].ArriveTime;
-            keyFrames[i].DepartureTime = keyFrames[i].ArriveTime;
-        }
-    }
+        for (uint32 mapId : *mapsUsed)
+            ASSERT(!sMapStore.LookupEntry(mapId)->Instanceable());
 
-    keyFrames.back().NextArriveTime = keyFrames.back().DepartureTime;
+        transport->InInstance = false;
+    }
+    else
+        transport->InInstance = sMapStore.LookupEntry(*mapsUsed->begin())->Instanceable();
 
-    transport->pathTime = keyFrames.back().DepartureTime;
+    transport->TotalPathTime = totalTime;
 }
 
 void TransportMgr::AddPathNodeToTransport(uint32 transportEntry, uint32 timeSeg, TransportAnimationEntry const* node)
@@ -477,16 +580,22 @@ Transport* TransportMgr::CreateTransport(uint32 entry, ObjectGuid::LowType guid
         return nullptr;
     }
 
+    Optional<Position> startingPosition = tInfo->ComputePosition(0, nullptr, nullptr);
+    if (!startingPosition)
+    {
+        TC_LOG_ERROR("sql.sql", "Transport %u will not be loaded, failed to compute starting position", entry);
+        return nullptr;
+    }
+
     // create transport...
     Transport* trans = new Transport();
 
     // ...at first waypoint
-    TaxiPathNodeEntry const* startNode = tInfo->keyFrames.begin()->Node;
-    uint32 mapId = startNode->ContinentID;
-    float x = startNode->Loc.X;
-    float y = startNode->Loc.Y;
-    float z = startNode->Loc.Z;
-    float o = tInfo->keyFrames.begin()->InitialOrientation;
+    uint32 mapId = tInfo->PathLegs.front().MapId;
+    float x = startingPosition->GetPositionX();
+    float y = startingPosition->GetPositionY();
+    float z = startingPosition->GetPositionZ();
+    float o = startingPosition->GetOrientation();
 
     // initialize the gameobject base
     ObjectGuid::LowType guidLow = guid ? guid : ASSERT_NOTNULL(map)->GenerateLowGuid<HighGuid::Transport>();
@@ -500,7 +609,7 @@ Transport* TransportMgr::CreateTransport(uint32 entry, ObjectGuid::LowType guid
 
     if (MapEntry const* mapEntry = sMapStore.LookupEntry(mapId))
     {
-        if (mapEntry->Instanceable() != tInfo->inInstance)
+        if (mapEntry->Instanceable() != tInfo->InInstance)
         {
             TC_LOG_ERROR("entities.transport", "Transport %u (name: %s) attempted creation in instance map (id: %u) but it is not an instanced transport!", entry, trans->GetName().c_str(), mapId);
             delete trans;
@@ -525,7 +634,7 @@ void TransportMgr::SpawnContinentTransports()
     uint32 count = 0;
 
     for (auto itr = _transportSpawns.begin(); itr != _transportSpawns.end(); ++itr)
-        if (!ASSERT_NOTNULL(GetTransportTemplate(itr->second.TransportGameObjectId))->inInstance)
+        if (!ASSERT_NOTNULL(GetTransportTemplate(itr->second.TransportGameObjectId))->InInstance)
             if (CreateTransport(itr->second.TransportGameObjectId, itr->second.SpawnId, nullptr, itr->second.PhaseUseFlags, itr->second.PhaseId, itr->second.PhaseGroup))
                 ++count;
 
diff --git a/src/server/game/Maps/TransportMgr.h b/src/server/game/Maps/TransportMgr.h
index 92ce809faee..66f6d59e35c 100644
--- a/src/server/game/Maps/TransportMgr.h
+++ b/src/server/game/Maps/TransportMgr.h
@@ -19,11 +19,12 @@
 #define TRANSPORTMGR_H
 
 #include "ObjectGuid.h"
+#include "Optional.h"
+#include "Position.h"
 #include <map>
 #include <memory>
 #include <unordered_map>
 
-struct KeyFrame;
 struct GameObjectTemplate;
 struct TaxiPathNodeEntry;
 struct TransportAnimationEntry;
@@ -38,49 +39,69 @@ namespace Movement
 }
 
 using TransportSpline = Movement::Spline<double>;
-using KeyFrameVec = std::vector<KeyFrame>;
 
-struct KeyFrame
+enum class TransportMovementState : uint8
 {
-    explicit KeyFrame(TaxiPathNodeEntry const* node) : Index(0), Node(node), InitialOrientation(0.0f),
-        DistSinceStop(-1.0f), DistUntilStop(-1.0f), DistFromPrev(-1.0f), TimeFrom(0.0f), TimeTo(0.0f),
-        Teleport(false), ArriveTime(0), DepartureTime(0), Spline(nullptr), NextDistFromPrev(0.0f), NextArriveTime(0)
-    {
-    }
-
-    uint32 Index;
-    TaxiPathNodeEntry const* Node;
-    float InitialOrientation;
-    float DistSinceStop;
-    float DistUntilStop;
-    float DistFromPrev;
-    float TimeFrom;
-    float TimeTo;
-    bool Teleport;
-    uint32 ArriveTime;
-    uint32 DepartureTime;
-    std::shared_ptr<TransportSpline> Spline;
-
-    // Data needed for next frame
-    float NextDistFromPrev;
-    uint32 NextArriveTime;
-
-    bool IsTeleportFrame() const { return Teleport; }
-    bool IsStopFrame() const;
+    Moving,
+    WaitingOnPauseWaypoint
+};
+
+// Represents a segment within path leg between stops
+struct TransportPathSegment
+{
+    uint32 SegmentEndArrivalTimestamp = 0;
+    uint32 Delay = 0;
+    double DistanceFromLegStartAtEnd = 0.0;
+};
+
+struct TransportPathEvent
+{
+    uint32 Timestamp = 0;
+    uint32 EventId = 0;
+};
+
+// Represents a contignuous part of transport path (without map changes or teleports)
+struct TransportPathLeg
+{
+    TransportPathLeg();
+    ~TransportPathLeg();
+
+    TransportPathLeg(TransportPathLeg const&) = delete;
+    TransportPathLeg(TransportPathLeg&&) noexcept;
+    TransportPathLeg& operator=(TransportPathLeg const&) = delete;
+    TransportPathLeg& operator=(TransportPathLeg&&) noexcept;
+
+    uint32 MapId = 0;
+    std::unique_ptr<TransportSpline> Spline;
+    uint32 StartTimestamp = 0;
+    uint32 Duration = 0;
+    std::vector<TransportPathSegment> Segments;
 };
 
 struct TransportTemplate
 {
-    TransportTemplate() : inInstance(false), pathTime(0), accelTime(0.0f), accelDist(0.0f), entry(0) { }
+    TransportTemplate();
     ~TransportTemplate();
 
-    std::set<uint32> mapsUsed;
-    bool inInstance;
-    uint32 pathTime;
-    KeyFrameVec keyFrames;
-    float accelTime;
-    float accelDist;
-    uint32 entry;
+    TransportTemplate(TransportTemplate const&) = delete;
+    TransportTemplate(TransportTemplate&&) noexcept;
+    TransportTemplate& operator=(TransportTemplate const&) = delete;
+    TransportTemplate& operator=(TransportTemplate&&) noexcept;
+
+    uint32 TotalPathTime = 0;
+    double Speed = 0.0;
+    double AccelerationRate = 0.0;
+    double AccelerationTime = 0.0;
+    double AccelerationDistance = 0.0;
+    std::vector<TransportPathLeg> PathLegs;
+    std::vector<TransportPathEvent> Events;
+
+    Optional<Position> ComputePosition(uint32 time, TransportMovementState* moveState, size_t* legIndex) const;
+    uint32 GetNextPauseWaypointTimestamp(uint32 time) const;
+
+    double CalculateDistanceMoved(double timePassedInSegment, double segmentDuration, bool isFirstSegment, bool isLastSegment) const;
+
+    bool InInstance = false;
 };
 
 struct TC_GAME_API TransportAnimation
@@ -142,7 +163,7 @@ class TC_GAME_API TransportMgr
         TransportMgr& operator=(TransportMgr const&) = delete;
 
         // Generates and precaches a path for transport to avoid generation each time transport instance is created
-        void GeneratePath(GameObjectTemplate const* goInfo, TransportTemplate* transport);
+        void GeneratePath(GameObjectTemplate const* goInfo, TransportTemplate* transport, std::set<uint32>* mapsUsed);
 
         void AddPathNodeToTransport(uint32 transportEntry, uint32 timeSeg, TransportAnimationEntry const* node);