public void UpdateAdjacentTile(Tile adjacentTile)
{
if (adjacentTile.IsVisited) return;
if (adjacentTile.Type == TileType.Wall) return;
// Compute adjacente tile distance to exit
double distance = this.DistanceToExit + adjacentTile.Type.Weight;
if (distance < adjacentTile.DistanceToExit)
{
// Udpate distance
adjacentTile.DistanceToExit = distance;
// Reallocate path
if (adjacentTile.Next != null)
adjacentTile.Next.Ancestors.Remove(adjacentTile);
adjacentTile.Next = this;
this.Ancestors.Add(adjacentTile);
}
}
private void ResetTile(Tile targetTile)
{
targetTile.Next = null;
targetTile.DistanceToExit = double.MaxValue;
foreach (Tile tile in targetTile.GetNeighbours(this))
{
if (tile.Type != TileType.Wall)
tile.IsVisited = false;
}
targetTile.Ancestors.ForEach(
tile => this.ResetTile(tile)
);
targetTile.Ancestors.Clear();
}
private LinkedList<Tile> GetPathForTile(Tile tile)
{
LinkedList<Tile> newPath = new LinkedList<Tile>();
while (tile != null)
{
newPath.AddLast(tile);
tile = tile.Next;
}
return newPath;
}
private void InitializeTiles()
{
this.Tiles = new Tile[this.Width * this.Height];
for (int h = 0; h < this.Height; h++)
{
for (int w = 0; w < this.Width; w++)
{
Tile tile = new Tile()
{
Position = new Vector2(w * tileTexture.Width, h * tileTexture.Height),
Type = TileType.Free,
MapX = w,
MapY = h
};
this.Tiles[h * this.Width + w] = tile;
}
}
}
private void BackwardUpdate(Tile source, Tile target)
{
// Check if we should use the source as new path
if(source.DistanceToExit + target.Type.Weight < target.DistanceToExit) {
if(target.Next != null) target.Next.Ancestors.Remove(target);
target.Next = source;
source.Ancestors.Add(target);
target.DistanceToExit = source.DistanceToExit + target.Type.Weight;
foreach (Tile tile in target.GetNeighbours(this))
{
if(tile.Type == TileType.Wall) continue;
if(tile == target.Next) continue;
this.BackwardUpdate(target, tile);
}
}
}