def mobility(board: Board):
mobility = 0
if board.turn == WHITE:
mobility -= sum(1 for m in board.generate_pseudo_legal_moves()
if not board.is_into_check(m))
board.push(Move.null())
mobility += sum(1 for m in board.generate_pseudo_legal_moves()
if not board.is_into_check(m))
board.pop()
else:
mobility += sum(1 for m in board.generate_pseudo_legal_moves()
if not board.is_into_check(m))
board.push(Move.null())
mobility -= sum(1 for m in board.generate_pseudo_legal_moves()
if not board.is_into_check(m))
board.pop()
return mobility
def slide_move(board: chess.Board, move: chess.Move) -> Optional[chess.Move]:
psuedo_legal_moves = list(board.generate_pseudo_legal_moves())
squares = list(
chess.SquareSet(chess.BB_BETWEEN[move.from_square][
move.to_square])) + [move.to_square]
squares = sorted(squares,
key=lambda s: chess.square_distance(s, move.from_square),
reverse=True)
for slide_square in squares:
revised = chess.Move(move.from_square, slide_square, move.promotion)
if revised in psuedo_legal_moves:
return revised
return None
class Viridithas():
def __init__(
self,
human: bool = False,
fen: str = 'rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1',
pgn: str = '',
time_limit: float = 15,
fun: bool = False,
contempt: int = 3000,
book: bool = True,
advancedTC: list = [],
):
if pgn == '':
self.node = Board(fen)
else:
self.node = Board()
for move in pgn.split():
try:
self.node.push_san(move)
except Exception:
continue
self.time_limit = time_limit
if advancedTC:
self.endpoint = time.time()+advancedTC[0]*60
self.increment = advancedTC[1]
else:
self.endpoint = 0
self.increment = 0
self.fun = fun
self.contempt = contempt
self.human = human
self.nodes = 0
self.advancedTC = advancedTC
self.hashtable: dict[Hashable, TTEntry] = dict()
self.inbook = book
def set_position(self, fen):
self.node = Board(fen)
def __repr__(self) -> str:
return str(self.node) + '\n' + self.__class__.__name__+"-engine at position " + str(self.node.fen())
def __str__(self) -> str:
return self.__class__.__name__
def user_setup(self):
if input("Do you want to configure the bot? (Y/N) ").upper() != 'Y':
return
myname = self.__class__.__name__.upper()
print(f"BEGINNING USER CONFIGURATION OF {myname}-BOT")
datadict = get_engine_parameters()
self.__init__(
human=datadict["human"],
fen=datadict["fen"],
pgn=datadict["pgn"],
time_limit=datadict["time_limit"],
fun=datadict["fun"],
contempt=datadict["contempt"],
book=datadict["book"],
advancedTC=datadict["advancedTC"]
)
def gameover_check_info(self):
checkmate = self.node.is_checkmate()
draw = self.node.is_stalemate() or \
self.node.is_insufficient_material( ) or \
self.node.is_repetition(2) or self.node.is_seventyfive_moves() or not any(self.node.generate_legal_moves())
return checkmate or draw, checkmate, draw
# @profile
def evaluate(self, depth: float, checkmate: bool, draw: bool) -> float:
self.nodes += 1
if checkmate:
return MATE_VALUE * int(max(depth+1, 1)) * (1 if self.node.turn else -1)
if draw:
return -self.contempt * (1 if self.node.turn else -1)
rating: float = 0
rating += pst_eval(self.node)
# rating += see_eval(self.node)
# rating += mobility(self.node) * MOBILITY_FACTOR
# rating += piece_attack_counts(self.node) * ATTACK_FACTOR
# rating += king_safety(self.node) * KING_SAFETY_FACTOR
# rating += space(self.node) * SPACE_FACTOR
return rating
def single_hash_iterator(self, best):
yield best
def captures_piece(self, p): # concentrate on MVV, then LVA
return itertools.chain(
self.node.generate_pseudo_legal_moves(self.node.pawns, p),
self.node.generate_pseudo_legal_moves(self.node.knights, p),
self.node.generate_pseudo_legal_moves(self.node.bishops, p),
self.node.generate_pseudo_legal_moves(self.node.rooks, p),
self.node.generate_pseudo_legal_moves(self.node.queens, p),
self.node.generate_pseudo_legal_moves(self.node.kings, p),
)
#@profile
def captures(self): # (MVV/LVA)
return (m for m in itertools.chain(
self.captures_piece(
self.node.occupied_co[not self.node.turn] & self.node.queens),
self.captures_piece(
self.node.occupied_co[not self.node.turn] & self.node.rooks),
self.captures_piece(
self.node.occupied_co[not self.node.turn] & self.node.bishops),
self.captures_piece(
self.node.occupied_co[not self.node.turn] & self.node.knights),
self.captures_piece(
self.node.occupied_co[not self.node.turn] & self.node.pawns),
) if self.node.is_legal(m))
def winning_captures(self): # (MVV/LVA)
target_all = self.node.occupied_co[not self.node.turn]
target_3 = target_all & ~self.node.pawns
target_5 = target_3 & (~self.node.bishops | ~self.node.knights)
target_9 = target_5 & ~self.node.rooks
return itertools.chain(
self.node.generate_pseudo_legal_moves(self.node.pawns, target_all),
self.node.generate_pseudo_legal_moves(self.node.knights, target_3),
self.node.generate_pseudo_legal_moves(self.node.bishops, target_3),
self.node.generate_pseudo_legal_moves(self.node.rooks, target_5),
self.node.generate_pseudo_legal_moves(self.node.queens, target_9),
self.node.generate_pseudo_legal_moves(self.node.kings, target_9),
)
def losing_captures(self): # (MVV/LVA)
target_pawns = self.node.pawns
target_pnb = target_pawns | self.node.bishops | self.node.knights
target_pnbr = target_pnb | self.node.rooks
return itertools.chain(
self.node.generate_pseudo_legal_moves(self.node.knights, target_pawns),
self.node.generate_pseudo_legal_moves(self.node.bishops, target_pawns),
self.node.generate_pseudo_legal_moves(self.node.rooks, target_pnb),
self.node.generate_pseudo_legal_moves(self.node.queens, target_pnbr),
self.node.generate_pseudo_legal_moves(self.node.kings, target_pnbr),
)
def ordered_moves(self):
return (m for m in itertools.chain(
# self.winning_captures(),
self.captures_piece(
self.node.occupied_co[not self.node.turn] & self.node.queens),
self.captures_piece(
self.node.occupied_co[not self.node.turn] & self.node.rooks),
self.captures_piece(
self.node.occupied_co[not self.node.turn] & self.node.bishops),
self.captures_piece(
self.node.occupied_co[not self.node.turn] & self.node.knights),
self.captures_piece(
self.node.occupied_co[not self.node.turn] & self.node.pawns),
self.node.generate_pseudo_legal_moves(
0xffff_ffff_ffff_ffff, ~self.node.occupied_co[not self.node.turn]),
# self.losing_captures()
) if self.node.is_legal(m))
def pass_turn(self) -> None:
self.node.push(Move.from_uci("0000"))
#@profile
def qsearch(self, alpha: float, beta: float, depth: float, colour: int, gameover: bool, checkmate: bool, draw: bool) -> float:
val = self.evaluate(1, checkmate, draw) * colour
if gameover:
return val
if val >= beta:
return beta
if (val < alpha - QUEEN_VALUE):
return alpha
alpha = max(val, alpha)
for capture in self.captures():
self.node.push(capture)
gameover, checkmate, draw = self.gameover_check_info()
score = -self.qsearch(-beta, -alpha, depth - 1, -colour, gameover, checkmate, draw)
self.node.pop()
if score >= beta:
return score
alpha = max(score, alpha)
return alpha
def tt_lookup(self, board: Board) -> "TTEntry":
key = board._transposition_key()
return self.hashtable.get(key, TTEntry.default())
def tt_store(self, board: Board, entry: TTEntry):
key = board._transposition_key()
self.hashtable[key] = entry
#@profile
def negamax(self, depth: float, colour: int, alpha: float, beta: float) -> float:
initial_alpha = alpha
# (* Transposition Table Lookup; self.node is the lookup key for ttEntry *)
tt_entry = self.tt_lookup(self.node)
if not tt_entry.is_null() and tt_entry.depth >= depth:
if tt_entry.type == EXACT:
return tt_entry.value
elif tt_entry.type == LOWERBOUND:
alpha = max(alpha, tt_entry.value)
elif tt_entry.type == UPPERBOUND:
beta = min(beta, tt_entry.value)
if alpha >= beta:
return tt_entry.value
if self.node.is_legal(tt_entry.best):
moves = itertools.chain([tt_entry.best], filter(lambda x: x != tt_entry.best, self.ordered_moves()))
else:
moves = self.ordered_moves()
else:
moves = self.ordered_moves()
gameover, checkmate, draw = self.gameover_check_info()
if gameover:
return colour * self.evaluate(depth, checkmate, draw)
if depth < 1:
return self.qsearch(alpha, beta, depth, colour, gameover, checkmate, draw)
current_pos_is_check = self.node.is_check()
if not current_pos_is_check and depth >= 3 and abs(alpha) < MATE_VALUE and abs(beta) < MATE_VALUE:
# MAKE A NULL MOVE
self.node.push(Move.null())
# PERFORM A LIMITED SEARCH
value = - self.negamax(depth - 3, -colour, -beta, -beta + 1)
# UNMAKE NULL MOVE
self.node.pop()
if value >= beta:
return beta
do_prune = self.pruning(depth, colour, alpha, beta, current_pos_is_check)
best_move = Move.null()
search_pv = True
value = float("-inf")
for move_idx, move in enumerate(moves):
if move_idx == 0:
best_move = move
gives_check = self.node.gives_check(move)
is_capture = self.node.is_capture(move)
is_promo = bool(move.promotion)
depth_reduction = search_reduction_factor(
move_idx, current_pos_is_check, gives_check, is_capture, is_promo, depth)
if do_prune:
if not gives_check and not is_capture:
continue
self.node.push(move)
if search_pv:
r = -self.negamax(depth - depth_reduction, -colour, -beta, -alpha)
value = max(value, r)
else:
r = -self.negamax(depth - depth_reduction, -colour, -alpha-1, -alpha)
if (r > alpha): # // in fail-soft ... & & value < beta) is common
r = -self.negamax(depth - depth_reduction, -colour, -beta, -alpha) #// re-search
value = max(value, r)
self.node.pop()
if value > alpha:
alpha = value
best_move = move
alpha = max(alpha, value)
if alpha >= beta:
break
search_pv = False
# (* Transposition Table Store; self.node is the lookup key for ttEntry *)
# ttEntry = TTEntry()
tt_entry.value = value
if value <= initial_alpha:
tt_entry.type = UPPERBOUND
elif value >= beta:
tt_entry.type = LOWERBOUND
else:
tt_entry.type = EXACT
tt_entry.depth = depth
tt_entry.best = best_move
tt_entry.null = False
self.tt_store(self.node, tt_entry)
return value
def pruning(self, depth, colour, alpha, beta, current_pos_is_check):
if not (not current_pos_is_check and abs(
alpha) < MATE_VALUE / 2 and abs(beta) < MATE_VALUE / 2) or depth > 2:
return False
see = see_eval(self.node) * colour
DO_D1_PRUNING = depth <= 1 and see + FUTILITY_MARGIN < alpha
DO_D2_PRUNING = depth <= 2 and see + FUTILITY_MARGIN_2 < alpha
return DO_D1_PRUNING or DO_D2_PRUNING
def move_sort(self, moves: list, ratings: list):
pairs = zip(*sorted(zip(moves, ratings), key=operator.itemgetter(1)))
moves, ratings = [list(pair) for pair in pairs]
return moves, ratings
def pv_string(self):
count = 0
moves = []
while True:
e = self.tt_lookup(self.node)
if e.is_null() or not self.node.is_legal(e.best):
break
# print(self.node.__str__())
# print(self.node.__repr__())
# print(e.best)
# print(self.node.san(e.best))
moves.append(self.node.san(e.best))
self.node.push(e.best)
count += 1
for _ in moves:
self.node.pop()
if count == 0: return ""
return " ".join(moves)
def turnmod(self) -> int:
return -1 if self.node.turn else 1
def show_iteration_data(self, moves: list, values: list, depth: float, start: float) -> tuple:
t = round(time.time()-start, 2)
print(f"{self.node.san(moves[0])} | {-round((self.turnmod()*values[0])/1000, 3)} | {str(t)}s at depth {str(depth + 1)}, {str(self.nodes)} nodes processed, at {str(int(self.nodes / (t+0.00001)))}NPS.\n", f"PV: {self.pv_string()}\n", end="")
return (self.node.san(moves[0]), self.turnmod()*values[0], self.nodes, depth+1, t)
def search(self, ponder: bool = False, readout: bool = True):
val = float("-inf")
start_time = time.time()
self.nodes = 0
moves = [next(self.ordered_moves())]
saved_position = deepcopy(self.node)
alpha, beta = float("-inf"), float("inf")
valWINDOW = PAWN_VALUE / 4
WINDOW_FAILED = False
try:
depth = 1
while depth < 40:
best = self.tt_lookup(self.node).best
time_elapsed = time.time() - start_time
# check if we aren't going to finish the next search in time
if time_elapsed > 0.5 * self.time_limit and not ponder and not WINDOW_FAILED:
return best, val
val = self.negamax(
depth, self.turnmod(), alpha=alpha, beta=beta)
# print(val)
if ((val <= alpha) or (val >= beta)):
# We fell outside the window, so try again with a
# full-width window (and the same depth).
alpha = float("-inf")
beta = float("inf")
WINDOW_FAILED = True
continue
WINDOW_FAILED = False
best = self.tt_lookup(self.node).best
# check if we've run out of time
if time_elapsed > self.time_limit and not ponder:
return best, val
moves = [self.tt_lookup(self.node).best]
values = [self.tt_lookup(self.node).value]
if readout:
self.show_iteration_data(moves, values, depth, start_time)
alpha = val - valWINDOW # Set up the window for the next iteration.
beta = val + valWINDOW
depth += 1
except KeyboardInterrupt:
self.node = saved_position
pass
return moves[0], val
def ponder(self) -> None:
self.origin = self.node.copy()
self.search(ponder=True)
def get_book_move(self):
# book = chess.polyglot.open_reader(
# r"ProDeo292/ProDeo292/books/elo2500.bin")
book = chess.polyglot.open_reader(
r"books/elo2500.bin")
main_entry = book.find(self.node)
choice = book.weighted_choice(self.node)
book.close()
return main_entry.move, choice.move
def engine_move(self) -> Move:
# add flag_func for egtb mode
if self.advancedTC:
self.time_limit = (self.endpoint-time.time())/20
print("Time for move: " + str(round(self.time_limit, 2)) + "s")
if self.inbook:
try:
best, choice = self.get_book_move()
if self.fun:
self.node.push(choice)
return choice
else:
self.node.push(best)
print(chess.pgn.Game.from_board(self.node)[-1])
except IndexError:
self.time_limit = self.time_limit*2
best, _ = self.search()
self.node.push(best)
print(chess.pgn.Game.from_board(self.node)[-1])
self.inbook = False
self.time_limit = self.time_limit/2
else:
best, _ = self.search()
self.node.push(best)
print(chess.pgn.Game.from_board(self.node)[-1])
# self.record_stack()
self.endpoint += self.increment
return best
def user_move(self) -> str:
move = input("enter move: ")
while True:
try:
self.node.push_san(move)
break
except Exception:
move = input("enter move: ")
return move
def display_ending(self) -> None:
if self.node.is_stalemate():
print('END BY STALEMATE')
elif self.node.is_insufficient_material():
print('END BY INSUFFICIENT MATERIAL')
elif self.node.is_fivefold_repetition():
print('END BY FIVEFOLD REPETITION')
elif self.node.is_checkmate:
print("BLACK" if self.node.turn == BLACK else "WHITE", 'WINS ON TURN',
self.node.fullmove_number)
else:
print('END BY UNKNOWN REASON')
def run_game(self, indefinite=True) -> str:
while not self.node.is_game_over():
print(self.__repr__())
if self.human and self.node.turn:
try:
self.ponder()
except KeyboardInterrupt:
self.node = self.origin
self.user_move()
else: # SWAP THESE ASAP
self.engine_move()
if not indefinite:
break
self.display_ending()
try:
return str(chess.pgn.Game.from_board(self.node)[-1])
except Exception:
return "PGN ERROR"
def play_viri(self, fen=None):
player_colour = input(
"Enter the human player's colour in the form b/w\n--> ")
while player_colour not in ['b', 'w']:
player_colour = input(
"Enter the human player's colour in the form b/w\n--> ")
player_colour = WHITE if player_colour == 'w' else BLACK
timeControl = int(
input("how many seconds should viri get per move?\n--> "))
self.__init__(human=True, time_limit=timeControl, fen=fen, book=True, fun=False)
self.fun = False
while not self.node.is_game_over():
print(self.__repr__())
if player_colour == self.node.turn:
# try:
# self.ponder()
# except KeyboardInterrupt:
# self.node = self.origin
# self.user_move()
self.user_move()
else:
self.engine_move()
self.display_ending()
def perftx(self, n):
if n == 0:
self.nodes += 1
else:
for move in self.ordered_moves():
self.node.push(move)
self.perftx(n - 1)
self.node.pop()
def perft(self, n):
self.nodes = 0
self.perftx(n)
print(self.nodes)
def uci(self):
start = input()
while start != "uci":
start = input()
print("id", end="")
while True:
command = input()
if command == "ucinewgame":
board = Board()
elif command.split()[0] == "position":
fen = command[command.index(
"fen") + 3: command.index("moves") - 1]
moves = command[command.index("moves"):].split()
if fen == "startpos":
fen = 'rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1'
board = Board(fen)
for move in moves:
board.push(Move.from_uci(move))