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")
 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):
 176                 piece = self.grid[x][y]
 177                 if piece.types[type_index] == "unknown":
 178                         if not state in self.unrevealed_types[piece.colour].keys() and sanity == True:
 179                                 raise Exception("SANITY: Too many " + piece.colour + " " + state + "s")
 180                         self.unrevealed_types[piece.colour][state] -= 1
 181                         if self.unrevealed_types[piece.colour][state] <= 0:
 182                                 del self.unrevealed_types[piece.colour][state]
 183
 184                 piece.types[type_index] = state
 185                 piece.current_type = state
 186
 187                 if len(self.possible_moves(piece)) <= 0:
 188                         piece.deselect() # Piece can't move; deselect it
 189
 190                 # Piece needs to recalculate moves
 191                 piece.possible_moves = None
 192
 193         # Update the board when a piece has been moved
 194         def update_move(self, x, y, x2, y2, sanity=True):
 195
 196                 piece = self.grid[x][y]
 197                 #print "Moving " + str(x) + "," + str(y) + " to " + str(x2) + "," + str(y2) + "; possible_moves are " + str(self.possible_moves(piece))
 198
 199                 if not [x2,y2] in self.possible_moves(piece) and sanity == True:
 200                         raise Exception("ILLEGAL move " + str(x2)+","+str(y2))
 201
 202                 self.grid[x][y] = None
 203                 taken = self.grid[x2][y2]
 204                 if taken != None:
 205                         if taken.current_type == "king":
 206                                 self.king[taken.colour] = None
 207                         self.pieces[taken.colour].remove(taken)
 208                 self.grid[x2][y2] = piece
 209                 piece.x = x2
 210                 piece.y = y2
 211
 212                 # If the piece is a pawn, and it reaches the final row, it becomes a queen
 213                 # I know you are supposed to get a choice
 214                 # But that would be effort
 215                 if piece.current_type == "pawn" and ((piece.colour == "white" and piece.y == 0) or (piece.colour == "black" and piece.y == h-1)):
 216                         if self.style == "classical":
 217                                 piece.types[0] = "queen"
 218                                 piece.types[1] = "queen"
 219                         else:
 220                                 piece.types[piece.choice] = "queen"
 221                         piece.current_type = "queen"
 222
 223                 piece.deselect() # Uncollapse (?) the wavefunction!
 224                 self.moves += 1
 225
 226                 # All other pieces need to recalculate moves
 227                 for p in self.pieces["white"] + self.pieces["black"]:
 228                         p.possible_moves = None
 229
 230                 #self.verify()
 231
 232         # Update the board from a string
 233         # Guesses what to do based on the format of the string
 234         def update(self, result, sanity=True):
 235                 #print "Update called with \"" + str(result) + "\""
 236                 # String always starts with 'x y'
 237                 try:
 238                         s = result.split(" ")
 239                         [x,y] = map(int, s[0:2])
 240                 except:
 241                         raise Exception("GIBBERISH \""+ str(result) + "\"") # Raise expectations
 242
 243                 piece = self.grid[x][y]
 244                 if piece == None and sanity == True:
 245                         raise Exception("EMPTY")
 246
 247                 # If a piece is being moved, the third token is '->'
 248                 # We could get away with just using four integers, but that wouldn't look as cool
 249                 if "->" in s:
 250                         # Last two tokens are the destination
 251                         try:
 252                                 [x2,y2] = map(int, s[3:])
 253                         except:
 254                                 raise Exception("GIBBERISH \"" + str(result) + "\"") # Raise the alarm
 255
 256                         # Move the piece (take opponent if possible)
 257                         self.update_move(x, y, x2, y2, sanity)
 258
 259                 else:
 260                         # Otherwise we will just assume a piece has been selected
 261                         try:
 262                                 type_index = int(s[2]) # We need to know which of the two types the piece is in; that's the third token
 263                                 state = s[3] # The last token is a string identifying the type
 264                         except:
 265                                 raise Exception("GIBBERISH \"" + result + "\"") # Throw a hissy fit
 266
 267
 268                         # Select the piece
 269                         self.update_select(x, y, type_index, state, sanity)
 270
 271                 return result
 272
 273         # Gets each piece that could reach the given square and the probability that it could reach that square
 274         # Will include allied pieces that defend the attacker
 275         def coverage(self, x, y, colour = None, reject_allied = True):
 276                 result = {}
 277
 278                 if colour == None:
 279                         pieces = self.pieces["white"] + self.pieces["black"]
 280                 else:
 281                         pieces = self.pieces[colour]
 282
 283                 for p in pieces:
 284                         prob = self.probability_grid(p, reject_allied)[x][y]
 285                         if prob > 0:
 286                                 result.update({p : prob})
 287
 288                 #self.verify()
 289                 return result
 290
 291
 292
 293
 294
 295         # Associates each square with a probability that the piece could move into it
 296         # Look, I'm doing all the hard work for you here...
 297         def probability_grid(self, p, reject_allied = True):
 298
 299                 result = [[0.0] * w for _ in range(h)]
 300                 if not isinstance(p, Piece):
 301                         return result
 302
 303                 if p.current_type != "unknown":
 304                         #sys.stderr.write(sys.argv[0] + ": " + str(p) + " moves " + str(self.possible_moves(p, reject_allied)) + "\n")
 305                         for point in self.possible_moves(p, reject_allied):
 306                                 result[point[0]][point[1]] = 1.0
 307                         return result
 308
 309
 310                 for i in range(len(p.types)):
 311                         t = p.types[i]
 312                         prob = 1.0 / float(len(p.types))
 313                         if t == "unknown" or p.types[i][0] == '?':
 314                                 total_types = 0
 315                                 for t2 in self.unrevealed_types[p.colour].keys():
 316                                         total_types += self.unrevealed_types[p.colour][t2]
 317
 318                                 for t2 in self.unrevealed_types[p.colour].keys():
 319                                         prob2 = float(self.unrevealed_types[p.colour][t2]) / float(total_types)
 320                                         #p.current_type = t2
 321                                         for point in self.possible_moves(p, reject_allied, state=t2):
 322                                                 result[point[0]][point[1]] += prob2 * prob
 323
 324                         else:
 325                                 #p.current_type = t
 326                                 for point in self.possible_moves(p, reject_allied, state=t):
 327                                                 result[point[0]][point[1]] += prob
 328
 329                 #self.verify()
 330                 #p.current_type = "unknown"
 331                 return result
 332
 333         def prob_is_type(self, p, state):
 334                 prob = 0.5
 335                 result = 0
 336                 for i in range(len(p.types)):
 337                         t = p.types[i]
 338                         if t == state:
 339                                 result += prob
 340                                 continue
 341                         if t == "unknown" or p.types[i][0] == '?':
 342                                 total_prob = 0
 343                                 for t2 in self.unrevealed_types[p.colour].keys():
 344                                         total_prob += self.unrevealed_types[p.colour][t2]
 345                                 for t2 in self.unrevealed_types[p.colour].keys():
 346                                         if t2 == state:
 347                                                 result += prob * float(self.unrevealed_types[p.colour][t2]) / float(total_prob)
 348
 349
 350
 351         # Get all squares that the piece could move into
 352         # This is probably inefficient, but I looked at some sample chess games and they seem to actually do things this way
 353         # reject_allied indicates whether squares occupied by allied pieces will be removed
 354         # (set to false to check for defense)
 355         def possible_moves(self, p, reject_allied = True, state=None):
 356                 if p == None:
 357                         raise Exception("SANITY: No piece")
 358
 359
 360
 361                 if state != None and state != p.current_type:
 362                         old_type = p.current_type
 363                         p.current_type = state
 364                         result = self.possible_moves(p, reject_allied, state=None)
 365                         p.current_type = old_type
 366                         return result
 367
 368
 369
 370
 371                 result = []
 372
 373
 374
 375                 if p.current_type == "unknown":
 376                         raise Exception("SANITY: Piece state unknown")
 377                         # The below commented out code causes things to break badly
 378                         #for t in p.types:
 379                         #       if t == "unknown":
 380                         #               continue
 381                         #       p.current_type = t
 382                         #       result += self.possible_moves(p)
 383                         #p.current_type = "unknown"
 384                         #return result
 385
 386                 if p.current_type == "king":
 387                         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]]
 388                 elif p.current_type == "queen":
 389                         for d in [[-1,0],[1,0],[0,-1],[0,1],[-1,-1],[-1,1],[1,-1],[1,1]]:
 390                                 result += self.scan(p.x, p.y, d[0], d[1])
 391                 elif p.current_type == "bishop":
 392                         for d in [[-1,-1],[-1,1],[1,-1],[1,1]]: # There's a reason why bishops move diagonally
 393                                 result += self.scan(p.x, p.y, d[0], d[1])
 394                 elif p.current_type == "rook":
 395                         for d in [[-1,0],[1,0],[0,-1],[0,1]]:
 396                                 result += self.scan(p.x, p.y, d[0], d[1])
 397                 elif p.current_type == "knight":
 398                         # I would use two lines, but I'm not sure how python likes that
 399                         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]]
 400                 elif p.current_type == "pawn":
 401                         if p.colour == "white":
 402
 403                                 # Pawn can't move forward into occupied square
 404                                 if self.on_board(p.x, p.y-1) and self.grid[p.x][p.y-1] == None:
 405                                         result = [[p.x,p.y-1]]
 406                                 for f in [[p.x-1,p.y-1],[p.x+1,p.y-1]]:
 407                                         if not self.on_board(f[0], f[1]):
 408                                                 continue
 409                                         if self.grid[f[0]][f[1]] != None:  # Pawn can take diagonally
 410                                                 result.append(f)
 411                                 if p.y == h-2:
 412                                         # Slightly embarrassing if the pawn jumps over someone on its first move...
 413                                         if self.grid[p.x][p.y-1] == None and self.grid[p.x][p.y-2] == None:
 414                                                 result.append([p.x, p.y-2])
 415                         else:
 416                                 # Vice versa for the black pawn
 417                                 if self.on_board(p.x, p.y+1) and self.grid[p.x][p.y+1] == None:
 418                                         result = [[p.x,p.y+1]]
 419
 420                                 for f in [[p.x-1,p.y+1],[p.x+1,p.y+1]]:
 421                                         if not self.on_board(f[0], f[1]):
 422                                                 continue
 423                                         if self.grid[f[0]][f[1]] != None:
 424                                                 #sys.stderr.write(sys.argv[0] + " : "+str(p) + " can take " + str(self.grid[f[0]][f[1]]) + "\n")
 425                                                 result.append(f)
 426                                 if p.y == 1:
 427                                         if self.grid[p.x][p.y+1] == None and self.grid[p.x][p.y+2] == None:
 428                                                 result.append([p.x, p.y+2])
 429
 430                         #sys.stderr.write(sys.argv[0] + " : possible_moves for " + str(p) + " " + str(result) + "\n")
 431
 432                 # Remove illegal moves
 433                 # Note: The result[:] creates a copy of result, so that the result.remove calls don't fuck things up
 434                 for point in result[:]:
 435
 436                         if (point[0] < 0 or point[0] >= w) or (point[1] < 0 or point[1] >= h):
 437                                 result.remove(point) # Remove locations outside the board
 438                                 continue
 439                         g = self.grid[point[0]][point[1]]
 440
 441                         if g != None and (g.colour == p.colour and reject_allied == True):
 442                                 result.remove(point) # Remove allied pieces
 443
 444                 #self.verify()
 445
 446                 p.possible_moves = result
 447                 return result
 448
 449
 450         # Scans in a direction until it hits a piece, returns all squares in the line
 451         # (includes the final square (which contains a piece), but not the original square)
 452         def scan(self, x, y, vx, vy):
 453                 p = []
 454
 455                 xx = x
 456                 yy = y
 457                 while True:
 458                         xx += vx
 459                         yy += vy
 460                         if not self.on_board(xx, yy):
 461                                 break
 462                         if not [xx,yy] in p:
 463                                 p.append([xx, yy])
 464                         g = self.grid[xx][yy]
 465                         if g != None:
 466                                 return p
 467
 468                 return p
 469
 470         # Returns "white", "black" or "DRAW" if the game should end
 471         def end_condition(self):
 472                 if self.king["white"] == None:
 473                         if self.king["black"] == None:
 474                                 return "DRAW" # This shouldn't happen
 475                         return "black"
 476                 elif self.king["black"] == None:
 477                         return "white"
 478                 elif len(self.pieces["white"]) == 1 and len(self.pieces["black"]) == 1:
 479                         return "DRAW"
 480                 elif self.max_moves != None and self.moves > self.max_moves:
 481                         return "DRAW"
 482                 return None
 483
 484
 485         # I typed the full statement about 30 times before writing this function...
 486         def on_board(self, x, y):
 487                 return (x >= 0 and x < w) and (y >= 0 and y < h)
 488
 489         # Pushes a move temporarily
 490         def push_move(self, piece, x, y):
 491                 target = self.grid[x][y]
 492                 self.move_stack.append([piece, target, piece.x, piece.y, x, y])
 493                 [piece.x, piece.y] = [x, y]
 494                 self.grid[x][y] = piece
 495                 self.grid[piece.x][piece.y] = None
 496
 497                 for p in self.pieces["white"] + self.pieces["black"]:
 498                         p.possible_moves = None
 499
 500         # Restore move
 501         def pop_move(self):
 502                 #print str(self.move_stack)
 503                 [piece, target, x1, y1, x2, y2] = self.move_stack[len(self.move_stack)-1]
 504                 self.move_stack = self.move_stack[:-1]
 505                 piece.x = x1
 506                 piece.y = y1
 507                 self.grid[x1][y1] = piece
 508                 if target != None:
 509                         target.x = x2
 510                         target.y = y2
 511                 self.grid[x2][y2] = target
 512
 513                 for p in self.pieces["white"] + self.pieces["black"]:
 514                                 p.possible_moves = None
 515