Core/Movement: Implement MoveSplineFlag::Enter_Cycle (#24049)

by xvwyh
#22448

5 files changed, 53 insertions, 10 deletions

diff --git a/src/server/game/Movement/MotionMaster.cpp b/src/server/game/Movement/MotionMaster.cpp
index fb7109499da..d266b855ed0 100644
--- a/src/server/game/Movement/MotionMaster.cpp
+++ b/src/server/game/Movement/MotionMaster.cpp
@@ -807,6 +807,9 @@ void MotionMaster::MoveCirclePath(float x, float y, float z, float radius, bool
 
     Movement::MoveSplineInit init(_owner);
 
+    // add the owner's current position as starting point as it gets removed after entering the cycle
+    init.Path().push_back(G3D::Vector3(_owner->GetPositionX(), _owner->GetPositionY(), _owner->GetPositionZ()));
+
     for (uint8 i = 0; i < stepCount; angle += step, ++i)
     {
         G3D::Vector3 point;
diff --git a/src/server/game/Movement/Spline/MoveSpline.cpp b/src/server/game/Movement/Spline/MoveSpline.cpp
index 3a03e24f0ec..991979ac83e 100644
--- a/src/server/game/Movement/Spline/MoveSpline.cpp
+++ b/src/server/game/Movement/Spline/MoveSpline.cpp
@@ -122,9 +122,8 @@ void MoveSpline::init_spline(MoveSplineInitArgs const& args)
     if (args.flags.cyclic)
     {
         uint32 cyclic_point = 0;
-        // MoveSplineFlag::Enter_Cycle support dropped
-        //if (splineflags & SPLINEFLAG_ENTER_CYCLE)
-        //cyclic_point = 1;   // shouldn't be modified, came from client
+        if (splineflags.enter_cycle)
+            cyclic_point = 1;   // shouldn't be modified, came from client
         spline.init_cyclic_spline(&args.path[0], args.path.size(), modes[args.flags.isSmooth()], cyclic_point, args.initialOrientation);
     }
     else
@@ -199,7 +198,10 @@ bool MoveSplineInitArgs::Validate(Unit* unit) const
 #define CHECK(exp) \
     if (!(exp))\
     {\
-        TC_LOG_ERROR("misc.movesplineinitargs", "MoveSplineInitArgs::Validate: expression '%s' failed for GUID: %u Entry: %u", #exp, unit->GetTypeId() == TYPEID_PLAYER ? unit->GetGUID().GetCounter() : unit->ToCreature()->GetSpawnId(), unit->GetEntry());\
+        if (unit)\
+            TC_LOG_ERROR("misc.movesplineinitargs", "MoveSplineInitArgs::Validate: expression '%s' failed for GUID: %u Entry: %u", #exp, unit->GetTypeId() == TYPEID_PLAYER ? unit->GetGUID().GetCounter() : unit->ToCreature()->GetSpawnId(), unit->GetEntry());\
+        else\
+            TC_LOG_ERROR("misc.movesplineinitargs", "MoveSplineInitArgs::Validate: expression '%s' failed for cyclic spline continuation", #exp); \
         return false;\
     }
     CHECK(path.size() > 1);
@@ -276,6 +278,41 @@ MoveSpline::UpdateResult MoveSpline::_updateState(int32& ms_time_diff)
                 point_Idx = spline.first();
                 time_passed = time_passed % Duration();
                 result = Result_NextCycle;
+
+                // Remove first point from the path after one full cycle.
+                // That point was the position of the unit prior to entering the cycle and it shouldn't be repeated with continuous cycles.
+                if (splineflags.enter_cycle)
+                {
+                    splineflags.enter_cycle = false;
+
+                    MoveSplineInitArgs args{ (size_t)spline.getPointCount() };
+                    args.path.assign(spline.getPoints().begin() + spline.first() + 1, spline.getPoints().begin() + spline.last());
+                    args.facing = facing;
+                    args.flags = splineflags;
+                    args.path_Idx_offset = point_Idx_offset;
+                    // MoveSplineFlag::Parabolic | MoveSplineFlag::Animation not supported currently
+                        //args.parabolic_amplitude = ?;
+                        //args.time_perc = ?;
+                    args.splineId = m_Id;
+                    args.initialOrientation = initialOrientation;
+                    args.velocity = 1.0f; // Calculated below
+                    args.HasVelocity = true;
+                    args.TransformForTransport = onTransport;
+                    if (args.Validate(nullptr))
+                    {
+                        // New cycle should preserve previous cycle's duration for some weird reason, even though
+                        // the path is really different now. Blizzard is weird. Or this was just a simple oversight.
+                        // Since our splines precalculate length with velocity in mind, if we want to find the desired
+                        // velocity, we have to make a fake spline, calculate its duration and then compare it to the
+                        // desired duration, thus finding out how much the velocity has to be increased for them to match.
+                        MoveSpline tempSpline;
+                        tempSpline.Initialize(args);
+                        args.velocity = (float)tempSpline.Duration() / Duration();
+
+                        if (args.Validate(nullptr))
+                            init_spline(args);
+                    }
+                }
             }
             else
             {
diff --git a/src/server/game/Movement/Spline/MoveSplineInit.cpp b/src/server/game/Movement/Spline/MoveSplineInit.cpp
index 749ffc98300..bb885671479 100644
--- a/src/server/game/Movement/Spline/MoveSplineInit.cpp
+++ b/src/server/game/Movement/Spline/MoveSplineInit.cpp
@@ -89,6 +89,7 @@ namespace Movement
         // corrent first vertex
         args.path[0] = real_position;
         args.initialOrientation = real_position.orientation;
+        args.flags.enter_cycle = args.flags.cyclic;
         move_spline.onTransport = transport;
 
         uint32 moveFlags = unit->m_movementInfo.GetMovementFlags();
diff --git a/src/server/game/Movement/Spline/MovementPacketBuilder.cpp b/src/server/game/Movement/Spline/MovementPacketBuilder.cpp
index e61887b931e..d5aad6c2625 100644
--- a/src/server/game/Movement/Spline/MovementPacketBuilder.cpp
+++ b/src/server/game/Movement/Spline/MovementPacketBuilder.cpp
@@ -68,8 +68,6 @@ namespace Movement
                 break;
         }
 
-        // add fake Enter_Cycle flag - needed for client-side cyclic movement (client will erase first spline vertex after first cycle done)
-        splineflags.enter_cycle = move_spline.isCyclic();
         data << uint32(splineflags & uint32(~MoveSplineFlag::Mask_No_Monster_Move));
 
         if (splineflags.animation)
@@ -124,10 +122,9 @@ namespace Movement
 
     void WriteCatmullRomCyclicPath(Spline<int32> const& spline, ByteBuffer& data)
     {
-        uint32 count = spline.getPointCount() - 3;
-        data << uint32(count + 1);
-        data << spline.getPoint(1); // fake point, client will erase it from the spline after first cycle done
-        data.append<G3D::Vector3>(&spline.getPoint(1), count);
+        uint32 count = spline.getPointCount() - 4;
+        data << count;
+        data.append<Vector3>(&spline.getPoint(2), count);
     }
 
     void PacketBuilder::WriteMonsterMove(MoveSpline const& move_spline, ByteBuffer& data)
@@ -187,4 +184,8 @@ namespace Movement
             data << (move_spline.isCyclic() ? G3D::Vector3::zero() : move_spline.FinalDestination());
         }
     }
+    void PacketBuilder::WriteSplineSync(MoveSpline const& move_spline, ByteBuffer& data)
+    {
+        data << (float)move_spline.timePassed() / move_spline.Duration();
+    }
 }
diff --git a/src/server/game/Movement/Spline/MovementPacketBuilder.h b/src/server/game/Movement/Spline/MovementPacketBuilder.h
index dd608bd48b5..80adbdfb185 100644
--- a/src/server/game/Movement/Spline/MovementPacketBuilder.h
+++ b/src/server/game/Movement/Spline/MovementPacketBuilder.h
@@ -37,6 +37,7 @@ namespace Movement
         static void WriteMonsterMove(MoveSpline const& mov, ByteBuffer& data);
         static void WriteStopMovement(G3D::Vector3 const& loc, uint32 splineId, ByteBuffer& data);
         static void WriteCreate(MoveSpline const& mov, ByteBuffer& data);
+        static void WriteSplineSync(MoveSpline const& mov, ByteBuffer& data);
     };
 }
 #endif // TRINITYSERVER_PACKET_BUILDER_H