Pacxon (#12)

* Add GridMovementAbility and PacXonGridInteractor for grid-based movement; integrate with PlayerController and PacXonLevel

* Add GhostMovementComponent and PacXonTrailComponent; integrate ghost movement and trail features in PacXonLevel

* Update main menu button focus and add new movement abilities; adjust player and ghost initialization in PacXonLevel

scripts/components/PacXonGridManager.cs

@@ -0,0 +1,121 @@
+using System.Collections.Generic;
+using System.Linq;
+using Godot;
+
+namespace Mr.BrickAdventures.scripts.components;
+
+public enum CellState
+{
+    Empty = -1,
+    Solid = 0,
+    Trail = 1,
+    Hunted = 2
+}
+
+[GlobalClass]
+public partial class PacXonGridManager : TileMapLayer
+{
+    [Export] public Rect2I PlayArea { get; set; } = new Rect2I(1, 1, 38, 28);
+    
+    private int _solidCellCount = 0;
+    private int _totalPlayableCells = 0;
+    
+    [Signal] public delegate void FillPercentageChangedEventHandler(float percentage);
+
+    public override void _Ready()
+    {
+        _totalPlayableCells = PlayArea.Size.X * PlayArea.Size.Y;
+        InitializeGrid();
+    }
+    
+    private void InitializeGrid()
+    {
+        Clear();
+        
+        for (var x = PlayArea.Position.X - 1; x <= PlayArea.End.X + 1; x++)
+        {
+            for (var y = PlayArea.Position.Y - 1; y <= PlayArea.End.Y + 1; y++)
+            {
+                if (x < PlayArea.Position.X || x > PlayArea.End.X || y < PlayArea.Position.Y || y > PlayArea.End.Y)
+                {
+                    SetCell(new Vector2I(x, y), (int)CellState.Solid, Vector2I.Zero);
+                }
+            }
+        }
+    }
+
+    public CellState GetCellState(Vector2I mapCoords)
+    {
+        var tileId = GetCellSourceId(mapCoords);
+        return (CellState)tileId;
+    }
+
+    public void SetCellState(Vector2I mapCoords, CellState state)
+    {
+        if (GetCellSourceId(mapCoords) != (int)CellState.Solid && state == CellState.Solid) _solidCellCount++;
+        SetCell(mapCoords, (int)state, Vector2I.Zero);
+    }
+    
+    public float GetFillPercentage()
+    {
+        return _totalPlayableCells > 0 ? (float)_solidCellCount / _totalPlayableCells : 0;
+    }
+
+    public void PerformFloodFill(List<Node2D> ghosts)
+    {
+        var unsafeCells = new HashSet<Vector2I>();
+
+        foreach (var ghost in ghosts.Where(IsInstanceValid))
+        {
+            var ghostPos = LocalToMap(ghost.Position);
+            FloodFillScan(ghostPos, unsafeCells);
+        } 
+        
+        var filledCount = 0;
+        for (var x = PlayArea.Position.X; x <= PlayArea.End.X; x++)
+        {
+            for (var y = PlayArea.Position.Y; y <= PlayArea.End.Y; y++)
+            {
+                var currentPos = new Vector2I(x, y);
+                if (GetCellState(currentPos) == CellState.Empty && !unsafeCells.Contains(currentPos))
+                {
+                    SetCellState(currentPos, CellState.Solid);
+                    filledCount++;
+                }
+            }
+        }
+        
+        if (filledCount > 0)
+        {
+            EmitSignal(SignalName.FillPercentageChanged, GetFillPercentage());
+        }
+    }
+    
+    private void FloodFillScan(Vector2I startPos, HashSet<Vector2I> visited)
+    {
+        if (!PlayArea.HasPoint(startPos) || visited.Contains(startPos)) return;
+
+        var q = new Queue<Vector2I>();
+        q.Enqueue(startPos);
+        visited.Add(startPos);
+
+        while (q.Count > 0)
+        {
+            var pos = q.Dequeue();
+            
+            var neighbors = new[]
+            {
+                pos + Vector2I.Up, pos + Vector2I.Down, pos + Vector2I.Left, pos + Vector2I.Right
+            };
+
+            foreach (var neighbor in neighbors)
+            {
+                if (PlayArea.HasPoint(neighbor) && !visited.Contains(neighbor) && GetCellState(neighbor) == CellState.Empty)
+                {
+                    visited.Add(neighbor);
+                    q.Enqueue(neighbor);
+                }
+            }
+        }
+    }
+}