Reorganizes Project (#41)

Projects/Scripts/Engines/Pathing/PathFollower.cs

@@ -0,0 +1,180 @@
+using System;
+using CalcMoves = Server.Movement.Movement;
+
+namespace Server
+{
+  public class PathFollower
+  {
+    // Should we use pathfinding? 'false' for not
+    private static bool Enabled = true;
+
+    private static TimeSpan RepathDelay = TimeSpan.FromSeconds(2.0);
+
+    private Mobile m_From;
+    private int m_Index;
+    private DateTime m_LastPathTime;
+    private Point3D m_Next, m_LastGoalLoc;
+    private MovementPath m_Path;
+
+    public PathFollower(Mobile from, IPoint3D goal)
+    {
+      m_From = from;
+      Goal = goal;
+    }
+
+    public MoveMethod Mover{ get; set; }
+
+    public IPoint3D Goal{ get; }
+
+    public MoveResult Move(Direction d)
+    {
+      if (Mover == null)
+        return m_From.Move(d) ? MoveResult.Success : MoveResult.Blocked;
+
+      return Mover(d);
+    }
+
+    public Point3D GetGoalLocation()
+    {
+      if (Goal is Item item)
+        return item.GetWorldLocation();
+
+      return new Point3D(Goal);
+    }
+
+    public void Advance(ref Point3D p, int index)
+    {
+      if (m_Path?.Success == true)
+      {
+        Direction[] dirs = m_Path.Directions;
+
+        if (index >= 0 && index < dirs.Length)
+        {
+          int x = p.X, y = p.Y;
+
+          CalcMoves.Offset(dirs[index], ref x, ref y);
+
+          p.X = x;
+          p.Y = y;
+        }
+      }
+    }
+
+    public void ForceRepath()
+    {
+      m_Path = null;
+    }
+
+    public bool CheckPath()
+    {
+      if (!Enabled)
+        return false;
+
+      Point3D goal = GetGoalLocation();
+
+      if (m_Path != null && (m_Path.Success && goal == m_LastGoalLoc || m_LastPathTime + RepathDelay > DateTime.Now) &&
+          !(m_Path.Success && Check(m_From.Location, m_LastGoalLoc, 0)))
+        return false;
+
+      m_LastPathTime = DateTime.UtcNow;
+      m_LastGoalLoc = goal;
+
+      m_Path = new MovementPath(m_From, goal);
+
+      m_Index = 0;
+      m_Next = m_From.Location;
+
+      Advance(ref m_Next, m_Index);
+
+      return true;
+
+    }
+
+    public bool Check(Point3D loc, Point3D goal, int range)
+    {
+      return Utility.InRange(loc, goal, range) && (range > 1 || Math.Abs(loc.Z - goal.Z) < 16);
+    }
+
+    public bool Follow(bool run, int range)
+    {
+      Point3D goal = GetGoalLocation();
+      Direction d;
+
+      if (Check(m_From.Location, goal, range))
+        return true;
+
+      bool repathed = CheckPath();
+
+      if (!(Enabled && m_Path.Success))
+      {
+        d = m_From.GetDirectionTo(goal);
+
+        if (run)
+          d |= Direction.Running;
+
+        m_From.SetDirection(d);
+        Move(d);
+
+        return Check(m_From.Location, goal, range);
+      }
+
+      d = m_From.GetDirectionTo(m_Next);
+
+      if (run)
+        d |= Direction.Running;
+
+      m_From.SetDirection(d);
+
+      MoveResult res = Move(d);
+
+      if (res == MoveResult.Blocked)
+      {
+        if (repathed)
+          return false;
+
+        m_Path = null;
+        CheckPath();
+
+        if (!m_Path.Success)
+        {
+          d = m_From.GetDirectionTo(goal);
+
+          if (run)
+            d |= Direction.Running;
+
+          m_From.SetDirection(d);
+          Move(d);
+
+          return Check(m_From.Location, goal, range);
+        }
+
+        d = m_From.GetDirectionTo(m_Next);
+
+        if (run)
+          d |= Direction.Running;
+
+        m_From.SetDirection(d);
+
+        res = Move(d);
+
+        if (res == MoveResult.Blocked)
+          return false;
+      }
+
+      if (m_From.X == m_Next.X && m_From.Y == m_Next.Y)
+      {
+        if (m_From.Z == m_Next.Z)
+        {
+          ++m_Index;
+          Advance(ref m_Next, m_Index);
+        }
+        else
+        {
+          m_Path = null;
+        }
+      }
+
+      return Check(m_From.Location, goal, range);
+    }
+  }
+}