fix(Core/Movement): fix calculation first Catmull-Rom spline point (#24449)

Co-authored-by: DanVS <33371360+DanVS@users.noreply.github.com>
Co-authored-by: Ryan Turner <16946913+TheSCREWEDSoftware@users.noreply.github.com>

src/server/game/Movement/Spline/MoveSpline.cpp

@@ -128,11 +128,11 @@ namespace Movement
             // MoveSplineFlag::Enter_Cycle support dropped
             //if (splineflags & SPLINEFLAG_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);
+            spline.init_cyclic_spline(&args.path[0], args.path.size(), modes[args.flags.isSmooth()], cyclic_point, args.initialOrientation);
         }
         else
         {
-            spline.init_spline(&args.path[0], args.path.size(), modes[args.flags.isSmooth()]);
+            spline.init_spline(&args.path[0], args.path.size(), modes[args.flags.isSmooth()], args.initialOrientation);
         }
 
         // init spline timestamps

src/server/game/Movement/Spline/Spline.cpp

@@ -199,18 +199,20 @@ namespace Movement
         return length;
     }
 
-    void SplineBase::init_spline(const Vector3* controls, index_type count, EvaluationMode m)
+    void SplineBase::init_spline(const Vector3* controls, index_type count, EvaluationMode m, float orientation)
     {
         m_mode = m;
         cyclic = false;
+        initialOrientation = orientation;
 
         (this->*initializers[m_mode])(controls, count, cyclic, 0);
     }
 
-    void SplineBase::init_cyclic_spline(const Vector3* controls, index_type count, EvaluationMode m, index_type cyclic_point)
+    void SplineBase::init_cyclic_spline(const Vector3* controls, index_type count, EvaluationMode m, index_type cyclic_point, float orientation)
     {
         m_mode = m;
         cyclic = true;
+        initialOrientation = orientation;
 
         (this->*initializers[m_mode])(controls, count, cyclic, cyclic_point);
     }
@@ -253,14 +255,18 @@ namespace Movement
             if (cyclic_point == 0)
                 points[0] = controls[count - 1];
             else
-                points[0] = controls[0].lerp(controls[1], -1);
+                points[0] = controls[0] - G3D::Vector3{ std::cos(initialOrientation), std::sin(initialOrientation), 0.0f };
 
             points[high_index + 1] = controls[cyclic_point];
             points[high_index + 2] = controls[cyclic_point + 1];
         }
         else
         {
-            points[0] = controls[0].lerp(controls[1], -1);
+            if (m_mode == ModeCatmullrom)
+                points[0] = controls[0] - G3D::Vector3{ std::cos(initialOrientation), std::sin(initialOrientation), 0.0f };
+            else
+                points[0] = controls[0].lerp(controls[1], -1);
+
             points[high_index + 1] = controls[count - 1];
         }
 

src/server/game/Movement/Spline/Spline.h

@@ -48,6 +48,7 @@ namespace Movement
 
         uint8 m_mode{UninitializedMode};
         bool cyclic{false};
+        float initialOrientation{0};
 
         enum
         {
@@ -116,8 +117,8 @@ namespace Movement
         [[nodiscard]] const Vector3& getPoint(index_type i) const { return points[i];}
 
         /** Initializes spline. Don't call other methods while spline not initialized. */
-        void init_spline(const Vector3* controls, index_type count, EvaluationMode m);
+        void init_spline(const Vector3* controls, index_type count, EvaluationMode m, float orientation);
-        void init_cyclic_spline(const Vector3* controls, index_type count, EvaluationMode m, index_type cyclic_point);
+        void init_cyclic_spline(const Vector3* controls, index_type count, EvaluationMode m, index_type cyclic_point, float orientation);
 
         /** As i can see there are a lot of ways how spline can be initialized
             would be no harm to have some custom initializers. */
@@ -170,8 +171,8 @@ namespace Movement
         void computeIndex(float t, index_type& out_idx, float& out_u) const;
 
         /** Initializes spline. Don't call other methods while spline not initialized. */
-        void init_spline(const Vector3* controls, index_type count, EvaluationMode m) { SplineBase::init_spline(controls, count, m);}
+        void init_spline(const Vector3* controls, index_type count, EvaluationMode m, float orientation = 0) { SplineBase::init_spline(controls, count, m, orientation);}
-        void init_cyclic_spline(const Vector3* controls, index_type count, EvaluationMode m, index_type cyclic_point) { SplineBase::init_cyclic_spline(controls, count, m, cyclic_point);}
+        void init_cyclic_spline(const Vector3* controls, index_type count, EvaluationMode m, index_type cyclic_point, float orientation = 0) { SplineBase::init_cyclic_spline(controls, count, m, cyclic_point, orientation);}
 
         /**  Initializes lengths with SplineBase::SegLength method. */
         void initLengths();