/// <summary>
/// Calculate a path from the start location to the destination location
/// </summary>
/// <remarks>
/// Based on the A* pathfinding algorithm described on Wikipedia
/// </remarks>
/// <see href="https://en.wikipedia.org/wiki/A*_search_algorithm#Pseudocode"/>
/// <param name="start">Start location</param>
/// <param name="goal">Destination location</param>
/// <param name="allowUnsafe">Allow possible but unsafe locations</param>
/// <returns>A list of locations, or null if calculation failed</returns>
public static Queue<Location> CalculatePath(World world, Location start, Location goal, bool allowUnsafe = false)
{
Queue<Location> result = null;
AutoTimeout.Perform(() =>
{
HashSet<Location> ClosedSet = new HashSet<Location>(); // The set of locations already evaluated.
HashSet<Location> OpenSet = new HashSet<Location>(new[] { start }); // The set of tentative nodes to be evaluated, initially containing the start node
Dictionary<Location, Location> Came_From = new Dictionary<Location, Location>(); // The map of navigated nodes.
Dictionary<Location, int> g_score = new Dictionary<Location, int>(); //:= map with default value of Infinity
g_score[start] = 0; // Cost from start along best known path.
// Estimated total cost from start to goal through y.
Dictionary<Location, int> f_score = new Dictionary<Location, int>(); //:= map with default value of Infinity
f_score[start] = (int)start.DistanceSquared(goal); //heuristic_cost_estimate(start, goal)
while (OpenSet.Count > 0)
{
Location current = //the node in OpenSet having the lowest f_score[] value
OpenSet.Select(location => f_score.ContainsKey(location)
? new KeyValuePair<Location, int>(location, f_score[location])
: new KeyValuePair<Location, int>(location, int.MaxValue))
.OrderBy(pair => pair.Value).First().Key;
if (current == goal)
{ //reconstruct_path(Came_From, goal)
List<Location> total_path = new List<Location>(new[] { current });
while (Came_From.ContainsKey(current))
{
current = Came_From[current];
total_path.Add(current);
}
total_path.Reverse();
result = new Queue<Location>(total_path);
}
OpenSet.Remove(current);
ClosedSet.Add(current);
foreach (Location neighbor in GetAvailableMoves(world, current, allowUnsafe))
{
if (ClosedSet.Contains(neighbor))
continue; // Ignore the neighbor which is already evaluated.
int tentative_g_score = g_score[current] + (int)current.DistanceSquared(neighbor); //dist_between(current,neighbor) // length of this path.
if (!OpenSet.Contains(neighbor)) // Discover a new node
OpenSet.Add(neighbor);
else if (tentative_g_score >= g_score[neighbor])
continue; // This is not a better path.
// This path is the best until now. Record it!
Came_From[neighbor] = current;
g_score[neighbor] = tentative_g_score;
f_score[neighbor] = g_score[neighbor] + (int)neighbor.DistanceSquared(goal); //heuristic_cost_estimate(neighbor, goal)
}
}
}, TimeSpan.FromSeconds(5));
return result;
}
/// <summary>
/// Get block at the specified location
/// </summary>
/// <param name="location">Location to retrieve block from</param>
/// <returns>Block at specified location or Air if the location is not loaded</returns>
public Block GetBlock(Location location)
{
ChunkColumn column = GetChunkColumn(location);
if (column != null)
{
Chunk chunk = column.GetChunk(location);
if (chunk != null)
return chunk.GetBlock(location);
}
return new Block(Material.Air);
}
public override string Run(McTcpClient handler, string command)
{
if (Settings.TerrainAndMovements)
{
string[] args = getArgs(command);
if (args.Length == 1)
{
string dirStr = getArg(command).Trim().ToLower();
Direction direction;
switch (dirStr)
{
case "up": direction = Direction.Up; break;
case "down": direction = Direction.Down; break;
case "east": direction = Direction.East; break;
case "west": direction = Direction.West; break;
case "north": direction = Direction.North; break;
case "south": direction = Direction.South; break;
case "get": return handler.GetCurrentLocation().ToString();
default: return "Unknown direction '" + dirStr + "'.";
}
if (Movement.CanMove(handler.GetWorld(), handler.GetCurrentLocation(), direction))
{
handler.MoveTo(Movement.Move(handler.GetCurrentLocation(), direction));
return "Moving " + dirStr + '.';
}
else return "Cannot move in that direction.";
}
else if (args.Length == 3)
{
try
{
int x = int.Parse(args[0]);
int y = int.Parse(args[1]);
int z = int.Parse(args[2]);
Location goal = new Location(x, y, z);
if (handler.MoveTo(goal))
return "Walking to " + goal;
return "Failed to compute path to " + goal;
}
catch (FormatException) { return CMDDesc; }
}
else return CMDDesc;
}
else return "Please enable terrainandmovements in config to use this command.";
}
/// <summary>
/// Set block at the specified location
/// </summary>
/// <param name="location">Location to set block to</param>
/// <param name="block">Block to set</param>
public void SetBlock(Location location, Block block)
{
ChunkColumn column = this[location.ChunkX, location.ChunkZ];
if (column != null)
{
Chunk chunk = column[location.ChunkY];
if (chunk == null)
column[location.ChunkY] = chunk = new Chunk();
chunk[location.ChunkBlockX, location.ChunkBlockY, location.ChunkBlockZ] = block;
}
}
/* ========= LOCATION PROPERTIES ========= */
/// <summary>
/// Check if the specified location is on the ground
/// </summary>
/// <param name="world">World for performing check</param>
/// <param name="location">Location to check</param>
/// <returns>True if the specified location is on the ground</returns>
public static bool IsOnGround(World world, Location location)
{
return world.GetBlock(Move(location, Direction.Down)).Type.IsSolid();
}
/// <summary>
/// Get a squared distance to the specified location
/// </summary>
/// <param name="location">Other location for computing distance</param>
/// <returns>Distance to the specified location, without using a square root</returns>
public double DistanceSquared(Location location)
{
return ((X - location.X) * (X - location.X))
+ ((Y - location.Y) * (Y - location.Y))
+ ((Z - location.Z) * (Z - location.Z));
}
/* ========= SIMPLE MOVEMENTS ========= */
/// <summary>
/// Check if the player can move in the specified direction
/// </summary>
/// <param name="world">World the player is currently located in</param>
/// <param name="location">Location the player is currently at</param>
/// <param name="direction">Direction the player is moving to</param>
/// <returns>True if the player can move in the specified direction</returns>
public static bool CanMove(World world, Location location, Direction direction)
{
switch (direction)
{
case Direction.Down:
return !IsOnGround(world, location);
case Direction.Up:
return (IsOnGround(world, location) || IsSwimming(world, location))
&& !world.GetBlock(Move(Move(location, Direction.Up), Direction.Up)).Type.IsSolid();
case Direction.East:
case Direction.West:
case Direction.South:
case Direction.North:
return !world.GetBlock(Move(location, direction)).Type.IsSolid()
&& !world.GetBlock(Move(Move(location, direction), Direction.Up)).Type.IsSolid();
default:
throw new ArgumentException("Unknown direction", "direction");
}
}
/// <summary>
/// Look at the specified location
/// </summary>
/// <param name="location">Location to look at</param>
protected void LookAtLocation(Mapping.Location location)
{
Handler.UpdateLocation(Handler.GetCurrentLocation(), location);
}
/// <summary>
/// Get exact distance to the specified location
/// </summary>
/// <param name="location">Other location for computing distance</param>
/// <returns>Distance to the specified location, with square root so lower performances</returns>
public double Distance(Location location)
{
return Math.Sqrt(DistanceSquared(location));
}
public bool SendLocationUpdate(Location location, bool onGround)
{
return false; //Currently not implemented
}
/// <summary>
/// Move to the specified location
/// </summary>
/// <param name="location">Location to reach</param>
/// <param name="allowUnsafe">Allow possible but unsafe locations thay may hurt the player: lava, cactus...</param>
/// <param name="allowSmallTeleport">Allow non-vanilla small teleport instead of computing path, but may cause invalid moves and/or trigger anti-cheat plugins</param>
/// <returns>True if a path has been found</returns>
protected bool MoveToLocation(Mapping.Location location, bool allowUnsafe = false, bool allowSmallTeleport = false)
{
return(Handler.MoveTo(location, allowUnsafe, allowSmallTeleport));
}
/* ========= PATHFINDING METHODS ========= */
/// <summary>
/// Handle movements due to gravity
/// </summary>
/// <param name="world">World the player is currently located in</param>
/// <param name="location">Location the player is currently at</param>
/// <returns>Updated location after applying gravity</returns>
public static Location HandleGravity(World world, Location location)
{
Location onFoots = new Location(location.X, Math.Floor(location.Y), location.Z);
Location belowFoots = Move(location, Direction.Down);
if (!IsOnGround(world, location) && !IsSwimming(world, location))
location = Move2Steps(location, belowFoots).Dequeue();
else if (!(world.GetBlock(onFoots).Type.IsSolid()))
location = Move2Steps(location, onFoots).Dequeue();
return location;
}
/// <summary>
/// Get chunk column at the specified location
/// </summary>
/// <param name="location">Location to retrieve chunk column</param>
/// <returns>The chunk column</returns>
public ChunkColumn GetChunkColumn(Location location)
{
return this[location.ChunkX, location.ChunkZ];
}
/// <summary>
/// Return a list of possible moves for the player
/// </summary>
/// <param name="world">World the player is currently located in</param>
/// <param name="location">Location the player is currently at</param>
/// <param name="allowUnsafe">Allow possible but unsafe locations</param>
/// <returns>A list of new locations the player can move to</returns>
public static IEnumerable<Location> GetAvailableMoves(World world, Location location, bool allowUnsafe = false)
{
List<Location> availableMoves = new List<Location>();
if (IsOnGround(world, location) || IsSwimming(world, location))
{
foreach (Direction dir in Enum.GetValues(typeof(Direction)))
if (CanMove(world, location, dir) && (allowUnsafe || IsSafe(world, Move(location, dir))))
availableMoves.Add(Move(location, dir));
}
else
{
foreach (Direction dir in new []{ Direction.East, Direction.West, Direction.North, Direction.South })
if (CanMove(world, location, dir) && IsOnGround(world, Move(location, dir)) && (allowUnsafe || IsSafe(world, Move(location, dir))))
availableMoves.Add(Move(location, dir));
availableMoves.Add(Move(location, Direction.Down));
}
return availableMoves;
}
/// <summary>
/// Called when the server sends a new player location,
/// or if a ChatBot whishes to update the player's location.
/// </summary>
/// <param name="location">The new location</param>
/// <param name="relative">If true, the location is relative to the current location</param>
public void UpdateLocation(Location location)
{
UpdateLocation(location, false);
}
/// <summary>
/// Called when the server sends a new player location,
/// or if a ChatBot whishes to update the player's location.
/// </summary>
/// <param name="location">The new location</param>
/// <param name="relative">If true, the location is relative to the current location</param>
public void UpdateLocation(Location location, bool relative)
{
lock (locationLock)
{
if (relative)
{
this.location += location;
}
else this.location = location;
locationReceived = true;
}
}
/// <summary>
/// Called ~10 times per second by the protocol handler
/// </summary>
public void OnUpdate()
{
foreach (var bot in bots.ToArray())
{
try
{
bot.Update();
bot.ProcessQueuedText();
}
catch (Exception e)
{
if (!(e is ThreadAbortException))
{
ConsoleIO.WriteLineFormatted("§8Update: Got error from " + bot.ToString() + ": " + e.ToString());
}
else throw; //ThreadAbortException should not be caught
}
}
if (Settings.TerrainAndMovements && locationReceived)
{
lock (locationLock)
{
for (int i = 0; i < 2; i++) //Needs to run at 20 tps; MCC runs at 10 tps
{
if (steps != null && steps.Count > 0)
location = steps.Dequeue();
else if (path != null && path.Count > 0)
steps = Movement.Move2Steps(location, path.Dequeue());
else location = Movement.HandleGravity(world, location);
handler.SendLocationUpdate(location, Movement.IsOnGround(world, location));
}
}
}
}
/// <summary>
/// Move to the specified location
/// </summary>
/// <param name="location">Location to reach</param>
/// <param name="allowUnsafe">Allow possible but unsafe locations</param>
/// <returns>True if a path has been found</returns>
public bool MoveTo(Location location, bool allowUnsafe = false)
{
lock (locationLock)
{
if (Movement.GetAvailableMoves(world, this.location, allowUnsafe).Contains(location))
path = new Queue<Location>(new[] { location });
else path = Movement.CalculatePath(world, this.location, location, allowUnsafe);
return path != null;
}
}
/// <summary>
/// Get chunk at the specified location
/// </summary>
/// <param name="location">Location, a modulo will be applied</param>
/// <returns>The chunk, or null if not loaded</returns>
public Chunk GetChunk(Location location)
{
return this[location.ChunkY];
}
/// <summary>
/// Check if the specified location is safe
/// </summary>
/// <param name="world">World for performing check</param>
/// <param name="location">Location to check</param>
/// <returns>True if the destination location won't directly harm the player</returns>
public static bool IsSafe(World world, Location location)
{
return
//No block that can harm the player
!world.GetBlock(location).Type.CanHarmPlayers()
&& !world.GetBlock(Move(location, Direction.Up)).Type.CanHarmPlayers()
&& !world.GetBlock(Move(location, Direction.Down)).Type.CanHarmPlayers()
//No fall from a too high place
&& (world.GetBlock(Move(location, Direction.Down)).Type.IsSolid()
|| world.GetBlock(Move(location, Direction.Down, 2)).Type.IsSolid()
|| world.GetBlock(Move(location, Direction.Down, 3)).Type.IsSolid())
//Not an underwater location
&& !(world.GetBlock(Move(location, Direction.Up)).Type.IsLiquid());
}
/// <summary>
/// Get block at the specified location
/// </summary>
/// <param name="location">Location, a modulo will be applied</param>
/// <returns>The block</returns>
public Block GetBlock(Location location)
{
return this[location.ChunkBlockX, location.ChunkBlockY, location.ChunkBlockZ];
}
/// <summary>
/// Check if the specified location implies swimming
/// </summary>
/// <param name="world">World for performing check</param>
/// <param name="location">Location to check</param>
/// <returns>True if the specified location implies swimming</returns>
public static bool IsSwimming(World world, Location location)
{
return world.GetBlock(location).Type.IsLiquid();
}
/// <summary>
/// Send a location update to the server
/// </summary>
/// <param name="location">The new location of the player</param>
/// <param name="onGround">True if the player is on the ground</param>
/// <returns>True if the location update was successfully sent</returns>
public bool SendLocationUpdate(Location location, bool onGround)
{
if (Settings.TerrainAndMovements)
{
try
{
SendPacket(protocolversion >= MC19Version ? 0x0C : 0x04, concatBytes(
getDouble(location.X), getDouble(location.Y), getDouble(location.Z),
new byte[] { onGround ? (byte)1 : (byte)0 }));
return true;
}
catch (SocketException) { return false; }
}
else return false;
}
/// <summary>
/// Get an updated location for moving in the specified direction
/// </summary>
/// <param name="location">Current location</param>
/// <param name="direction">Direction to move to</param>
/// <param name="length">Distance, in blocks</param>
/// <returns>Updated location</returns>
public static Location Move(Location location, Direction direction, int length = 1)
{
return location + Move(direction) * length;
}
/// <summary>
/// Move to the specified location
/// </summary>
/// <param name="location">Location to reach</param>
/// <param name="allowUnsafe">Allow possible but unsafe locations</param>
/// <returns>True if a path has been found</returns>
protected bool MoveToLocation(Mapping.Location location, bool allowUnsafe = false)
{
return(Handler.MoveTo(location, allowUnsafe));
}
/// <summary>
/// Decompose a single move from a block to another into several steps
/// </summary>
/// <remarks>
/// Allows moving by little steps instead or directly moving between blocks,
/// which would be rejected by anti-cheat plugins anyway.
/// </remarks>
/// <param name="start">Start location</param>
/// <param name="goal">Destination location</param>
/// <param name="stepsByBlock">Amount of steps by block</param>
/// <returns>A list of locations corresponding to the requested steps</returns>
public static Queue<Location> Move2Steps(Location start, Location goal, int stepsByBlock = 8)
{
if (stepsByBlock <= 0)
stepsByBlock = 1;
double totalStepsDouble = start.Distance(goal) * stepsByBlock;
int totalSteps = (int)Math.Ceiling(totalStepsDouble);
Location step = (goal - start) / totalSteps;
if (totalStepsDouble >= 1)
{
Queue<Location> movementSteps = new Queue<Location>();
for (int i = 1; i <= totalSteps; i++)
movementSteps.Enqueue(start + step * i);
return movementSteps;
}
else return new Queue<Location>(new[] { goal });
}
