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                 for c in ["black", "white"]:
  17                         del self.unrevealed_types[c]["unknown"]
  18
  19                 if style == "empty":
  20                         return
  21
  22                 # Add all the pieces with known primary types
  23                 for i in range(0, 2):
  24
  25                         s = ["black", "white"][i]
  26                         c = self.pieces[s]
  27                         y = [0, h-1][i]
  28
  29                         c.append(Piece(s, 0, y, ["rook"]))
  30                         c.append(Piece(s, 1, y, ["knight"]))
  31                         c.append(Piece(s, 2, y, ["bishop"]))
  32                         k = Piece(s, 3, y, ["king", "king"]) # There can only be one ruler!
  33                         k.types_revealed[1] = True
  34                         k.current_type = "king"
  35                         self.king[s] = k
  36                         c.append(k)
  37                         c.append(Piece(s, 4, y, ["queen"])) # Apparently he may have multiple wives though.
  38                         c.append(Piece(s, 5, y, ["bishop"]))
  39                         c.append(Piece(s, 6, y, ["knight"]))
  40                         c.append(Piece(s, 7, y, ["rook"]))
  41
  42                         if y == 0:
  43                                 y += 1
  44                         else:
  45                                 y -= 1
  46
  47                         # Lots of pawn
  48                         for x in range(0, w):
  49                                 c.append(Piece(s, x, y, ["pawn"]))
  50
  51                         types_left = {}
  52                         types_left.update(piece_types)
  53                         del types_left["king"] # We don't want one of these randomly appearing (although it might make things interesting...)
  54                         del types_left["unknown"] # We certainly don't want these!
  55                         for piece in c:
  56                                 # Add to grid
  57                                 self.grid[piece.x][piece.y] = piece
  58
  59                                 if len(piece.types) > 1:
  60                                         continue
  61                                 if style == "agent": # Assign placeholder "unknown" secondary type
  62                                         piece.types.append("unknown")
  63                                         continue
  64
  65                                 elif style == "quantum":
  66                                         # The master allocates the secondary types
  67                                         choice = types_left.keys()[random.randint(0, len(types_left.keys())-1)]
  68                                         types_left[choice] -= 1
  69                                         if types_left[choice] <= 0:
  70                                                 del types_left[choice]
  71                                         piece.types.append(choice)
  72                                 elif style == "classical":
  73                                         piece.types.append(piece.types[0])
  74                                         piece.current_type = piece.types[0]
  75                                         piece.types_revealed[1] = True
  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
  87         def display_grid(self, window = None, grid_sz = [80,80]):
  88                 if window == None:
  89                         return # I was considering implementing a text only display, then I thought "Fuck that"
  90
  91                 # The indentation is getting seriously out of hand...
  92                 for x in range(0, w):
  93                         for y in range(0, h):
  94                                 if (x + y) % 2 == 0:
  95                                         c = pygame.Color(200,200,200)
  96                                 else:
  97                                         c = pygame.Color(64,64,64)
  98                                 pygame.draw.rect(window, c, (x*grid_sz[0], y*grid_sz[1], (x+1)*grid_sz[0], (y+1)*grid_sz[1]))
  99
 100         def display_pieces(self, window = None, grid_sz = [80,80]):
 101                 if window == None:
 102                         return
 103                 for p in self.pieces["white"] + self.pieces["black"]:
 104                         p.draw(window, grid_sz, self.style)
 105
 106         # Draw the board in a pygame window
 107         def display(self, window = None):
 108                 self.display_grid(window)
 109                 self.display_pieces(window)
 110
 111
 112
 113
 114         def verify(self):
 115                 for x in range(w):
 116                         for y in range(h):
 117                                 if self.grid[x][y] == None:
 118                                         continue
 119                                 if (self.grid[x][y].x != x or self.grid[x][y].y != y):
 120                                         raise Exception(sys.argv[0] + ": MISMATCH " + str(self.grid[x][y]) + " should be at " + str(x) + "," + str(y))
 121
 122         # Select a piece on the board (colour is the colour of whoever is doing the selecting)
 123         def select(self, x,y, colour=None):
 124                 if not self.on_board(x, y): # Get on board everyone!
 125                         raise Exception("BOUNDS")
 126
 127                 piece = self.grid[x][y]
 128                 if piece == None:
 129                         raise Exception("EMPTY")
 130
 131                 if colour != None and piece.colour != colour:
 132                         raise Exception("COLOUR " + str(piece.colour) + " not " + str(colour))
 133
 134                 # I'm not quite sure why I made this return a string, but screw logical design
 135                 return str(x) + " " + str(y) + " " + str(piece.select()) + " " + str(piece.current_type)
 136
 137
 138         # Update the board when a piece has been selected
 139         # "type" is apparently reserved, so I'll use "state"
 140         def update_select(self, x, y, type_index, state):
 141                 piece = self.grid[x][y]
 142                 if piece.types[type_index] == "unknown":
 143                         if not state in self.unrevealed_types[piece.colour].keys():
 144                                 raise Exception("SANITY: Too many " + piece.colour + " " + state + "s")
 145                         self.unrevealed_types[piece.colour][state] -= 1
 146                         if self.unrevealed_types[piece.colour][state] <= 0:
 147                                 del self.unrevealed_types[piece.colour][state]
 148
 149                 piece.types[type_index] = state
 150                 piece.types_revealed[type_index] = True
 151                 piece.current_type = state
 152
 153                 if len(self.possible_moves(piece)) <= 0:
 154                         piece.deselect() # Piece can't move; deselect it
 155
 156         # Update the board when a piece has been moved
 157         def update_move(self, x, y, x2, y2):
 158                 piece = self.grid[x][y]
 159                 self.grid[x][y] = None
 160                 taken = self.grid[x2][y2]
 161                 if taken != None:
 162                         if taken.current_type == "king":
 163                                 self.king[taken.colour] = None
 164                         self.pieces[taken.colour].remove(taken)
 165                 self.grid[x2][y2] = piece
 166                 piece.x = x2
 167                 piece.y = y2
 168
 169                 # If the piece is a pawn, and it reaches the final row, it becomes a queen
 170                 # I know you are supposed to get a choice
 171                 # But that would be effort
 172                 if piece.current_type == "pawn" and ((piece.colour == "white" and piece.y == 0) or (piece.colour == "black" and piece.y == h-1)):
 173                         if self.style == "classical":
 174                                 piece.types[0] = "queen"
 175                                 piece.types[1] = "queen"
 176                         else:
 177                                 piece.types[piece.choice] = "queen"
 178                         piece.current_type = "queen"
 179
 180                 piece.deselect() # Uncollapse (?) the wavefunction!
 181                 self.verify()
 182
 183         # Update the board from a string
 184         # Guesses what to do based on the format of the string
 185         def update(self, result):
 186                 #print "Update called with \"" + str(result) + "\""
 187                 # String always starts with 'x y'
 188                 try:
 189                         s = result.split(" ")
 190                         [x,y] = map(int, s[0:2])
 191                 except:
 192                         raise Exception("GIBBERISH \""+ str(result) + "\"") # Raise expectations
 193
 194                 piece = self.grid[x][y]
 195                 if piece == None:
 196                         raise Exception("EMPTY")
 197
 198                 # If a piece is being moved, the third token is '->'
 199                 # We could get away with just using four integers, but that wouldn't look as cool
 200                 if "->" in s:
 201                         # Last two tokens are the destination
 202                         try:
 203                                 [x2,y2] = map(int, s[3:])
 204                         except:
 205                                 raise Exception("GIBBERISH \"" + str(result) + "\"") # Raise the alarm
 206
 207                         # Move the piece (take opponent if possible)
 208                         self.update_move(x, y, x2, y2)
 209
 210                 else:
 211                         # Otherwise we will just assume a piece has been selected
 212                         try:
 213                                 type_index = int(s[2]) # We need to know which of the two types the piece is in; that's the third token
 214                                 state = s[3] # The last token is a string identifying the type
 215                         except:
 216                                 raise Exception("GIBBERISH \"" + result + "\"") # Throw a hissy fit
 217
 218                         # Select the piece
 219                         self.update_select(x, y, type_index, state)
 220
 221                 return result
 222
 223         # Gets each piece that could reach the given square and the probability that it could reach that square
 224         # Will include allied pieces that defend the attacker
 225         def coverage(self, x, y, colour = None, reject_allied = True):
 226                 result = {}
 227
 228                 if colour == None:
 229                         pieces = self.pieces["white"] + self.pieces["black"]
 230                 else:
 231                         pieces = self.pieces[colour]
 232
 233                 for p in pieces:
 234                         prob = self.probability_grid(p, reject_allied)[x][y]
 235                         if prob > 0:
 236                                 result.update({p : prob})
 237
 238                 self.verify()
 239                 return result
 240
 241
 242
 243
 244
 245         # Associates each square with a probability that the piece could move into it
 246         # Look, I'm doing all the hard work for you here...
 247         def probability_grid(self, p, reject_allied = True):
 248
 249                 result = [[0.0] * w for _ in range(h)]
 250                 if not isinstance(p, Piece):
 251                         return result
 252
 253                 if p.current_type != "unknown":
 254                         #sys.stderr.write(sys.argv[0] + ": " + str(p) + " moves " + str(self.possible_moves(p, reject_allied)) + "\n")
 255                         for point in self.possible_moves(p, reject_allied):
 256                                 result[point[0]][point[1]] = 1.0
 257                         return result
 258
 259
 260                 for i in range(len(p.types)):
 261                         t = p.types[i]
 262                         prob = 0.5
 263                         if t == "unknown" or p.types_revealed[i] == False:
 264                                 total_types = 0
 265                                 for t2 in self.unrevealed_types[p.colour].keys():
 266                                         total_types += self.unrevealed_types[p.colour][t2]
 267
 268                                 for t2 in self.unrevealed_types[p.colour].keys():
 269                                         prob2 = float(self.unrevealed_types[p.colour][t2]) / float(total_types)
 270                                         p.current_type = t2
 271                                         for point in self.possible_moves(p, reject_allied):
 272                                                 result[point[0]][point[1]] += prob2 * prob
 273
 274                         else:
 275                                 p.current_type = t
 276                                 for point in self.possible_moves(p, reject_allied):
 277                                         result[point[0]][point[1]] += prob
 278
 279                 self.verify()
 280                 p.current_type = "unknown"
 281                 return result
 282
 283         def prob_is_type(self, p, state):
 284                 prob = 0.5
 285                 result = 0
 286                 for i in range(len(p.types)):
 287                         t = p.types[i]
 288                         if t == state:
 289                                 result += prob
 290                                 continue
 291                         if t == "unknown" or p.types_revealed[i] == False:
 292                                 total_prob = 0
 293                                 for t2 in self.unrevealed_types[p.colour].keys():
 294                                         total_prob += self.unrevealed_types[p.colour][t2]
 295                                 for t2 in self.unrevealed_types[p.colour].keys():
 296                                         if t2 == state:
 297                                                 result += prob * float(self.unrevealed_types[p.colour][t2]) / float(total_prob)
 298
 299
 300
 301         # Get all squares that the piece could move into
 302         # This is probably inefficient, but I looked at some sample chess games and they seem to actually do things this way
 303         # reject_allied indicates whether squares occupied by allied pieces will be removed
 304         # (set to false to check for defense)
 305         def possible_moves(self, p, reject_allied = True):
 306                 result = []
 307                 if p == None:
 308                         return result
 309
 310
 311                 if p.current_type == "unknown":
 312                         raise Exception("SANITY: Piece state unknown")
 313                         # The below commented out code causes things to break badly
 314                         #for t in p.types:
 315                         #       if t == "unknown":
 316                         #               continue
 317                         #       p.current_type = t
 318                         #       result += self.possible_moves(p)
 319                         #p.current_type = "unknown"
 320                         #return result
 321
 322                 if p.current_type == "king":
 323                         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]]
 324                 elif p.current_type == "queen":
 325                         for d in [[-1,0],[1,0],[0,-1],[0,1],[-1,-1],[-1,1],[1,-1],[1,1]]:
 326                                 result += self.scan(p.x, p.y, d[0], d[1])
 327                 elif p.current_type == "bishop":
 328                         for d in [[-1,-1],[-1,1],[1,-1],[1,1]]: # There's a reason why bishops move diagonally
 329                                 result += self.scan(p.x, p.y, d[0], d[1])
 330                 elif p.current_type == "rook":
 331                         for d in [[-1,0],[1,0],[0,-1],[0,1]]:
 332                                 result += self.scan(p.x, p.y, d[0], d[1])
 333                 elif p.current_type == "knight":
 334                         # I would use two lines, but I'm not sure how python likes that
 335                         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]]
 336                 elif p.current_type == "pawn":
 337                         if p.colour == "white":
 338
 339                                 # Pawn can't move forward into occupied square
 340                                 if self.on_board(p.x, p.y-1) and self.grid[p.x][p.y-1] == None:
 341                                         result = [[p.x,p.y-1]]
 342                                 for f in [[p.x-1,p.y-1],[p.x+1,p.y-1]]:
 343                                         if not self.on_board(f[0], f[1]):
 344                                                 continue
 345                                         if self.grid[f[0]][f[1]] != None:  # Pawn can take diagonally
 346                                                 result.append(f)
 347                                 if p.y == h-2:
 348                                         # Slightly embarrassing if the pawn jumps over someone on its first move...
 349                                         if self.grid[p.x][p.y-1] == None and self.grid[p.x][p.y-2] == None:
 350                                                 result.append([p.x, p.y-2])
 351                         else:
 352                                 # Vice versa for the black pawn
 353                                 if self.on_board(p.x, p.y+1) and self.grid[p.x][p.y+1] == None:
 354                                         result = [[p.x,p.y+1]]
 355
 356                                 for f in [[p.x-1,p.y+1],[p.x+1,p.y+1]]:
 357                                         if not self.on_board(f[0], f[1]):
 358                                                 continue
 359                                         if self.grid[f[0]][f[1]] != None:
 360                                                 #sys.stderr.write(sys.argv[0] + " : "+str(p) + " can take " + str(self.grid[f[0]][f[1]]) + "\n")
 361                                                 result.append(f)
 362                                 if p.y == 1:
 363                                         if self.grid[p.x][p.y+1] == None and self.grid[p.x][p.y+2] == None:
 364                                                 result.append([p.x, p.y+2])
 365
 366                         #sys.stderr.write(sys.argv[0] + " : possible_moves for " + str(p) + " " + str(result) + "\n")
 367
 368                 # Remove illegal moves
 369                 # Note: The result[:] creates a copy of result, so that the result.remove calls don't fuck things up
 370                 for point in result[:]:
 371
 372                         if (point[0] < 0 or point[0] >= w) or (point[1] < 0 or point[1] >= h):
 373                                 result.remove(point) # Remove locations outside the board
 374                                 continue
 375                         g = self.grid[point[0]][point[1]]
 376
 377                         if g != None and (g.colour == p.colour and reject_allied == True):
 378                                 result.remove(point) # Remove allied pieces
 379
 380                 self.verify()
 381                 return result
 382
 383
 384         # Scans in a direction until it hits a piece, returns all squares in the line
 385         # (includes the final square (which contains a piece), but not the original square)
 386         def scan(self, x, y, vx, vy):
 387                 p = []
 388
 389                 xx = x
 390                 yy = y
 391                 while True:
 392                         xx += vx
 393                         yy += vy
 394                         if not self.on_board(xx, yy):
 395                                 break
 396                         if not [xx,yy] in p:
 397                                 p.append([xx, yy])
 398                         g = self.grid[xx][yy]
 399                         if g != None:
 400                                 return p
 401
 402                 return p
 403
 404
 405
 406         # I typed the full statement about 30 times before writing this function...
 407         def on_board(self, x, y):
 408                 return (x >= 0 and x < w) and (y >= 0 and y < h)