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