qchess/src/board.py

   1 [w,h] = [8,8] # Width and height of board(s)
   2
   3 always_reveal_states = False
   4
   5 # Class to represent a quantum chess board
   6 class Board():
   7         # Initialise; if master=True then the secondary piece types are assigned
   8         #       Otherwise, they are left as unknown
   9         #       So you can use this class in Agent programs, and fill in the types as they are revealed
  10         def __init__(self, style="agent"):
  11                 self.style = style
  12                 self.pieces = {"white" : [], "black" : []}
  13                 self.grid = [[None] * w for _ in range(h)] # 2D List (you can get arrays in python, somehow, but they scare me)
  14                 self.unrevealed_types = {"white" : piece_types.copy(), "black" : piece_types.copy()}
  15                 self.king = {"white" : None, "black" : None} # We need to keep track of the king, because he is important
  16                 self.max_moves = None
  17                 self.moves = 0
  18                 self.move_stack = []
  19                 for c in ["black", "white"]:
  20                         del self.unrevealed_types[c]["unknown"]
  21
  22                 if style == "empty":
  23                         return
  24
  25                 # Add all the pieces with known primary types
  26                 for i in range(0, 2):
  27
  28                         s = ["black", "white"][i]
  29                         c = self.pieces[s]
  30                         y = [0, h-1][i]
  31
  32                         c.append(Piece(s, 0, y, ["rook"]))
  33                         c.append(Piece(s, 1, y, ["knight"]))
  34                         c.append(Piece(s, 2, y, ["bishop"]))
  35                         k = Piece(s, 3, y, ["king", "king"]) # There can only be one ruler!
  36                         k.current_type = "king"
  37                         self.king[s] = k
  38                         c.append(k)
  39                         c.append(Piece(s, 4, y, ["queen"])) # Apparently he may have multiple wives though.
  40                         c.append(Piece(s, 5, y, ["bishop"]))
  41                         c.append(Piece(s, 6, y, ["knight"]))
  42                         c.append(Piece(s, 7, y, ["rook"]))
  43
  44                         if y == 0:
  45                                 y += 1
  46                         else:
  47                                 y -= 1
  48
  49                         # Lots of pawn
  50                         for x in range(0, w):
  51                                 c.append(Piece(s, x, y, ["pawn"]))
  52
  53                         types_left = {}
  54                         types_left.update(piece_types)
  55                         del types_left["king"] # We don't want one of these randomly appearing (although it might make things interesting...)
  56                         del types_left["unknown"] # We certainly don't want these!
  57                         for piece in c:
  58                                 # Add to grid
  59                                 self.grid[piece.x][piece.y] = piece
  60
  61                                 if len(piece.types) > 1:
  62                                         continue
  63                                 if style == "agent": # Assign placeholder "unknown" secondary type
  64                                         piece.types.append("unknown")
  65                                         continue
  66
  67                                 elif style == "quantum":
  68                                         # The master allocates the secondary types
  69                                         choice = types_left.keys()[random.randint(0, len(types_left.keys())-1)]
  70                                         types_left[choice] -= 1
  71                                         if types_left[choice] <= 0:
  72                                                 del types_left[choice]
  73                                         piece.types.append('?' + choice)
  74                                 elif style == "classical":
  75                                         piece.types.append(piece.types[0])
  76                                         piece.current_type = piece.types[0]
  77                                         piece.choice = 0
  78
  79         def clone(self):
  80                 newboard = Board(master = False)
  81                 newpieces = newboard.pieces["white"] + newboard.pieces["black"]
  82                 mypieces = self.pieces["white"] + self.pieces["black"]
  83
  84                 for i in range(len(mypieces)):
  85                         newpieces[i].init_from_copy(mypieces[i])
  86
  87         # Reset the board from a string
  88         def reset_board(self, s):
  89                 self.pieces = {"white" : [], "black" : []}
  90                 self.king = {"white" : None, "black" : None}
  91                 self.grid = [[None] * w for _ in range(h)]
  92                 for x in range(w):
  93                         for y in range(h):
  94                                 self.grid[x][y] = None
  95
  96                 for line in s.split("\n"):
  97                         if line == "":
  98                                 continue
  99                         if line[0] == "#":
 100                                 continue
 101
 102                         tokens = line.split(" ")
 103                         [x, y] = map(int, tokens[len(tokens)-1].split(","))
 104                         current_type = tokens[1]
 105                         types = map(lambda e : e.strip(" '[],"), line.split('[')[1].split(']')[0].split(','))
 106
 107                         target = Piece(tokens[0], x, y, types)
 108                         target.current_type = current_type
 109
 110                         try:
 111                                 target.choice = types.index(current_type)
 112                         except:
 113                                 target.choice = -1
 114
 115                         self.pieces[tokens[0]].append(target)
 116                         if target.current_type == "king":
 117                                 self.king[tokens[0]] = target
 118
 119                         self.grid[x][y] = target
 120
 121
 122         def display_grid(self, window = None, grid_sz = [80,80]):
 123                 if window == None:
 124                         return # I was considering implementing a text only display, then I thought "Fuck that"
 125
 126                 # The indentation is getting seriously out of hand...
 127                 for x in range(0, w):
 128                         for y in range(0, h):
 129                                 if (x + y) % 2 == 0:
 130                                         c = pygame.Color(200,200,200)
 131                                 else:
 132                                         c = pygame.Color(64,64,64)
 133                                 pygame.draw.rect(window, c, (x*grid_sz[0], y*grid_sz[1], (x+1)*grid_sz[0], (y+1)*grid_sz[1]))
 134
 135         def display_pieces(self, window = None, grid_sz = [80,80]):
 136                 if window == None:
 137                         return
 138                 for p in self.pieces["white"] + self.pieces["black"]:
 139                         p.draw(window, grid_sz, self.style)
 140
 141         # Draw the board in a pygame window
 142         def display(self, window = None):
 143                 self.display_grid(window)
 144                 self.display_pieces(window)
 145
 146
 147
 148
 149         def verify(self):
 150                 for x in range(w):
 151                         for y in range(h):
 152                                 if self.grid[x][y] == None:
 153                                         continue
 154                                 if (self.grid[x][y].x != x or self.grid[x][y].y != y):
 155                                         raise Exception(sys.argv[0] + ": MISMATCH " + str(self.grid[x][y]) + " should be at " + str(x) + "," + str(y))
 156
 157         # Select a piece on the board (colour is the colour of whoever is doing the selecting)
 158         def select(self, x,y, colour=None):
 159                 if not self.on_board(x, y): # Get on board everyone!
 160                         raise Exception("BOUNDS " + str(x) + ","+str(y))
 161
 162                 piece = self.grid[x][y]
 163                 if piece == None:
 164                         raise Exception("EMPTY")
 165
 166                 if colour != None and piece.colour != colour:
 167                         raise Exception("COLOUR " + str(piece.colour) + " not " + str(colour))
 168
 169                 # I'm not quite sure why I made this return a string, but screw logical design
 170                 return str(x) + " " + str(y) + " " + str(piece.select()) + " " + str(piece.current_type)
 171
 172
 173         # Update the board when a piece has been selected
 174         # "type" is apparently reserved, so I'll use "state"
 175         def update_select(self, x, y, type_index, state, sanity=True, deselect=True):
 176                 #debug(str(self) + " update_select called")
 177                 piece = self.grid[x][y]
 178                 if piece.types[type_index] == "unknown":
 179                         if not state in self.unrevealed_types[piece.colour].keys() and sanity == True:
 180                                 raise Exception("SANITY: Too many " + piece.colour + " " + state + "s")
 181                         self.unrevealed_types[piece.colour][state] -= 1
 182                         if self.unrevealed_types[piece.colour][state] <= 0:
 183                                 del self.unrevealed_types[piece.colour][state]
 184
 185                 piece.types[type_index] = state
 186                 piece.current_type = state
 187
 188                 if deselect == True and len(self.possible_moves(piece)) <= 0:
 189                         piece.deselect() # Piece can't move; deselect it
 190
 191                 # Piece needs to recalculate moves
 192                 piece.possible_moves = None
 193
 194         # Update the board when a piece has been moved
 195         def update_move(self, x, y, x2, y2, sanity=True):
 196                 #debug(str(self) + " update_move called \""+str(x)+ " " + str(y) + " -> " + str(x2) + " " + str(y2) + "\"")
 197                 piece = self.grid[x][y]
 198                 #print "Moving " + str(x) + "," + str(y) + " to " + str(x2) + "," + str(y2) + "; possible_moves are " + str(self.possible_moves(piece))
 199
 200                 if not [x2,y2] in self.possible_moves(piece) and sanity == True:
 201                         raise Exception("ILLEGAL move " + str(x2)+","+str(y2))
 202
 203                 self.grid[x][y] = None
 204                 taken = self.grid[x2][y2]
 205                 if taken != None:
 206                         if taken.current_type == "king":
 207                                 self.king[taken.colour] = None
 208                         self.pieces[taken.colour].remove(taken)
 209                 self.grid[x2][y2] = piece
 210                 piece.x = x2
 211                 piece.y = y2
 212
 213                 # If the piece is a pawn, and it reaches the final row, it becomes a queen
 214                 # I know you are supposed to get a choice
 215                 # But that would be effort
 216                 if piece.current_type == "pawn" and ((piece.colour == "white" and piece.y == 0) or (piece.colour == "black" and piece.y == h-1)):
 217                         if self.style == "classical":
 218                                 piece.types[0] = "queen"
 219                                 piece.types[1] = "queen"
 220                         else:
 221                                 piece.types[piece.choice] = "queen"
 222                         piece.current_type = "queen"
 223
 224                 piece.deselect() # Uncollapse (?) the wavefunction!
 225                 self.moves += 1
 226
 227                 # All other pieces need to recalculate moves
 228                 for p in self.pieces["white"] + self.pieces["black"]:
 229                         p.possible_moves = None
 230
 231                 #self.verify()
 232
 233         # Update the board from a string
 234         # Guesses what to do based on the format of the string
 235         def update(self, result, sanity=True, deselect=True):
 236                 #debug(str(self) + " update called \""+str(result)+"\"")
 237                 # String always starts with 'x y'
 238                 try:
 239                         s = result.split(" ")
 240                         [x,y] = map(int, s[0:2])
 241                 except:
 242                         raise Exception("GIBBERISH \""+ str(result) + "\"") # Raise expectations
 243
 244                 piece = self.grid[x][y]
 245                 if piece == None and sanity == True:
 246                         raise Exception("EMPTY " + str(x) + " " + str(y))
 247
 248                 # If a piece is being moved, the third token is '->'
 249                 # We could get away with just using four integers, but that wouldn't look as cool
 250                 if "->" in s:
 251                         # Last two tokens are the destination
 252                         try:
 253                                 [x2,y2] = map(int, s[3:])
 254                         except:
 255                                 raise Exception("GIBBERISH \"" + str(result) + "\"") # Raise the alarm
 256
 257                         # Move the piece (take opponent if possible)
 258                         self.update_move(x, y, x2, y2, sanity)
 259
 260                 else:
 261                         # Otherwise we will just assume a piece has been selected
 262                         try:
 263                                 type_index = int(s[2]) # We need to know which of the two types the piece is in; that's the third token
 264                                 state = s[3] # The last token is a string identifying the type
 265                         except:
 266                                 raise Exception("GIBBERISH \"" + result + "\"") # Throw a hissy fit
 267
 268
 269                         # Select the piece
 270                         self.update_select(x, y, type_index, state, sanity=sanity, deselect=deselect)
 271
 272                 return result
 273
 274         # Gets each piece that could reach the given square and the probability that it could reach that square
 275         # Will include allied pieces that defend the attacker
 276         def coverage(self, x, y, colour = None, reject_allied = True):
 277                 result = {}
 278
 279                 if colour == None:
 280                         pieces = self.pieces["white"] + self.pieces["black"]
 281                 else:
 282                         pieces = self.pieces[colour]
 283
 284                 for p in pieces:
 285                         prob = self.probability_grid(p, reject_allied)[x][y]
 286                         if prob > 0:
 287                                 result.update({p : prob})
 288
 289                 #self.verify()
 290                 return result
 291
 292
 293
 294
 295
 296         # Associates each square with a probability that the piece could move into it
 297         # Look, I'm doing all the hard work for you here...
 298         def probability_grid(self, p, reject_allied = True):
 299
 300                 result = [[0.0] * w for _ in range(h)]
 301                 if not isinstance(p, Piece):
 302                         return result
 303
 304                 if p.current_type != "unknown":
 305                         #sys.stderr.write(sys.argv[0] + ": " + str(p) + " moves " + str(self.possible_moves(p, reject_allied)) + "\n")
 306                         for point in self.possible_moves(p, reject_allied):
 307                                 result[point[0]][point[1]] = 1.0
 308                         return result
 309
 310
 311                 for i in range(len(p.types)):
 312                         t = p.types[i]
 313                         prob = 1.0 / float(len(p.types))
 314                         if t == "unknown" or p.types[i][0] == '?':
 315                                 total_types = 0
 316                                 for t2 in self.unrevealed_types[p.colour].keys():
 317                                         total_types += self.unrevealed_types[p.colour][t2]
 318
 319                                 for t2 in self.unrevealed_types[p.colour].keys():
 320                                         prob2 = float(self.unrevealed_types[p.colour][t2]) / float(total_types)
 321                                         #p.current_type = t2
 322                                         for point in self.possible_moves(p, reject_allied, state=t2):
 323                                                 result[point[0]][point[1]] += prob2 * prob
 324
 325                         else:
 326                                 #p.current_type = t
 327                                 for point in self.possible_moves(p, reject_allied, state=t):
 328                                                 result[point[0]][point[1]] += prob
 329
 330                 #self.verify()
 331                 #p.current_type = "unknown"
 332                 return result
 333
 334         def prob_is_type(self, p, state):
 335                 if p.current_type != 0:
 336                         if state == p.current_type:
 337                                 return 1.0
 338                         else:
 339                                 return 0.0
 340
 341                 prob = 0.5
 342                 result = 0
 343                 for i in range(len(p.types)):
 344                         t = p.types[i]
 345                         if t == state:
 346                                 result += prob
 347                                 continue
 348                         if t == "unknown" or p.types[i][0] == '?':
 349                                 total_prob = 0
 350                                 for t2 in self.unrevealed_types[p.colour].keys():
 351                                         total_prob += self.unrevealed_types[p.colour][t2]
 352                                 for t2 in self.unrevealed_types[p.colour].keys():
 353                                         if t2 == state:
 354                                                 result += prob * float(self.unrevealed_types[p.colour][t2]) / float(total_prob)
 355
 356
 357
 358         # Get all squares that the piece could move into
 359         # This is probably inefficient, but I looked at some sample chess games and they seem to actually do things this way
 360         # reject_allied indicates whether squares occupied by allied pieces will be removed
 361         # (set to false to check for defense)
 362         def possible_moves(self, p, reject_allied = True, state=None):
 363                 if p == None:
 364                         raise Exception("SANITY: No piece")
 365
 366
 367
 368                 if state != None and state != p.current_type:
 369                         old_type = p.current_type
 370                         p.current_type = state
 371                         result = self.possible_moves(p, reject_allied, state=None)
 372                         p.current_type = old_type
 373                         return result
 374
 375
 376
 377
 378                 result = []
 379
 380
 381
 382                 if p.current_type == "unknown":
 383                         raise Exception("SANITY: Unknown state for piece: "+str(p))
 384                         # The below commented out code causes things to break badly
 385                         #for t in p.types:
 386                         #       if t == "unknown":
 387                         #               continue
 388                         #       p.current_type = t
 389                         #       result += self.possible_moves(p)
 390                         #p.current_type = "unknown"
 391                         #return result
 392
 393                 if p.current_type == "king":
 394                         result = [[p.x-1,p.y],[p.x+1,p.y],[p.x,p.y-1],[p.x,p.y+1], [p.x-1,p.y-1],[p.x-1,p.y+1],[p.x+1,p.y-1],[p.x+1,p.y+1]]
 395                 elif p.current_type == "queen":
 396                         for d in [[-1,0],[1,0],[0,-1],[0,1],[-1,-1],[-1,1],[1,-1],[1,1]]:
 397                                 result += self.scan(p.x, p.y, d[0], d[1])
 398                 elif p.current_type == "bishop":
 399                         for d in [[-1,-1],[-1,1],[1,-1],[1,1]]: # There's a reason why bishops move diagonally
 400                                 result += self.scan(p.x, p.y, d[0], d[1])
 401                 elif p.current_type == "rook":
 402                         for d in [[-1,0],[1,0],[0,-1],[0,1]]:
 403                                 result += self.scan(p.x, p.y, d[0], d[1])
 404                 elif p.current_type == "knight":
 405                         # I would use two lines, but I'm not sure how python likes that
 406                         result = [[p.x-2, p.y-1], [p.x-2, p.y+1], [p.x+2, p.y-1], [p.x+2,p.y+1], [p.x-1,p.y-2], [p.x-1, p.y+2],[p.x+1,p.y-2],[p.x+1,p.y+2]]
 407                 elif p.current_type == "pawn":
 408                         if p.colour == "white":
 409
 410                                 # Pawn can't move forward into occupied square
 411                                 if self.on_board(p.x, p.y-1) and self.grid[p.x][p.y-1] == None:
 412                                         result = [[p.x,p.y-1]]
 413                                 for f in [[p.x-1,p.y-1],[p.x+1,p.y-1]]:
 414                                         if not self.on_board(f[0], f[1]):
 415                                                 continue
 416                                         if self.grid[f[0]][f[1]] != None:  # Pawn can take diagonally
 417                                                 result.append(f)
 418                                 if p.y == h-2:
 419                                         # Slightly embarrassing if the pawn jumps over someone on its first move...
 420                                         if self.grid[p.x][p.y-1] == None and self.grid[p.x][p.y-2] == None:
 421                                                 result.append([p.x, p.y-2])
 422                         else:
 423                                 # Vice versa for the black pawn
 424                                 if self.on_board(p.x, p.y+1) and self.grid[p.x][p.y+1] == None:
 425                                         result = [[p.x,p.y+1]]
 426
 427                                 for f in [[p.x-1,p.y+1],[p.x+1,p.y+1]]:
 428                                         if not self.on_board(f[0], f[1]):
 429                                                 continue
 430                                         if self.grid[f[0]][f[1]] != None:
 431                                                 #sys.stderr.write(sys.argv[0] + " : "+str(p) + " can take " + str(self.grid[f[0]][f[1]]) + "\n")
 432                                                 result.append(f)
 433                                 if p.y == 1:
 434                                         if self.grid[p.x][p.y+1] == None and self.grid[p.x][p.y+2] == None:
 435                                                 result.append([p.x, p.y+2])
 436
 437                         #sys.stderr.write(sys.argv[0] + " : possible_moves for " + str(p) + " " + str(result) + "\n")
 438
 439                 # Remove illegal moves
 440                 # Note: The result[:] creates a copy of result, so that the result.remove calls don't fuck things up
 441                 for point in result[:]:
 442
 443                         if (point[0] < 0 or point[0] >= w) or (point[1] < 0 or point[1] >= h):
 444                                 result.remove(point) # Remove locations outside the board
 445                                 continue
 446                         g = self.grid[point[0]][point[1]]
 447
 448                         if g != None and (g.colour == p.colour and reject_allied == True):
 449                                 result.remove(point) # Remove allied pieces
 450
 451                 #self.verify()
 452
 453                 p.possible_moves = result
 454                 return result
 455
 456
 457         # Scans in a direction until it hits a piece, returns all squares in the line
 458         # (includes the final square (which contains a piece), but not the original square)
 459         def scan(self, x, y, vx, vy):
 460                 p = []
 461
 462                 xx = x
 463                 yy = y
 464                 while True:
 465                         xx += vx
 466                         yy += vy
 467                         if not self.on_board(xx, yy):
 468                                 break
 469                         if not [xx,yy] in p:
 470                                 p.append([xx, yy])
 471                         g = self.grid[xx][yy]
 472                         if g != None:
 473                                 return p
 474
 475                 return p
 476
 477         # Returns "white", "black" or "DRAW" if the game should end
 478         def end_condition(self):
 479                 if self.king["white"] == None:
 480                         if self.king["black"] == None:
 481                                 return "DRAW" # This shouldn't happen
 482                         return "black"
 483                 elif self.king["black"] == None:
 484                         return "white"
 485                 elif len(self.pieces["white"]) == 1 and len(self.pieces["black"]) == 1:
 486                         return "DRAW"
 487                 elif self.max_moves != None and self.moves > self.max_moves:
 488                         return "DRAW"
 489                 return None
 490
 491
 492         # I typed the full statement about 30 times before writing this function...
 493         def on_board(self, x, y):
 494                 return (x >= 0 and x < w) and (y >= 0 and y < h)
 495
 496
 497
 498         # Pushes a move temporarily
 499         def push_move(self, piece, x, y):
 500                 target = self.grid[x][y]
 501                 self.move_stack.append([piece, target, piece.x, piece.y, x, y])
 502                 [piece.x, piece.y] = [x, y]
 503                 self.grid[x][y] = piece
 504                 self.grid[piece.x][piece.y] = None
 505
 506                 for p in self.pieces["white"] + self.pieces["black"]:
 507                         p.possible_moves = None
 508
 509         # Restore move
 510         def pop_move(self):
 511                 #print str(self.move_stack)
 512                 [piece, target, x1, y1, x2, y2] = self.move_stack[len(self.move_stack)-1]
 513                 self.move_stack = self.move_stack[:-1]
 514                 piece.x = x1
 515                 piece.y = y1
 516                 self.grid[x1][y1] = piece
 517                 if target != None:
 518                         target.x = x2
 519                         target.y = y2
 520                 self.grid[x2][y2] = target
 521
 522                 for p in self.pieces["white"] + self.pieces["black"]:
 523                         p.possible_moves = None
 524