qchess/board.py

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