src/chess.lua

   1 local realchess = {}
   2 screwdriver = screwdriver or {}
   3
   4 local function index_to_xy(idx)
   5         idx = idx - 1
   6         local x = idx % 8
   7         local y = (idx - x) / 8
   8         return x, y
   9 end
  10
  11 local function xy_to_index(x, y)
  12         return x + y * 8 + 1
  13 end
  14
  15 local function get_square(a, b)
  16         return (a * 8) - (8 - b)
  17 end
  18
  19 local chat_prefix = minetest.colorize("#FFFF00", "[Chess] ")
  20 local letters = {'A','B','C','D','E','F','G','H'}
  21
  22 local rowDirs = {-1, -1, -1, 0, 0, 1, 1, 1}
  23 local colDirs = {-1, 0, 1, -1, 1, -1, 0, 1}
  24
  25 local bishopThreats = {true,  false, true,  false, false, true,  false, true}
  26 local rookThreats   = {false, true,  false, true,  true,  false, true,  false}
  27 local queenThreats  = {true,  true,  true,  true,  true,  true,  true,  true}
  28 local kingThreats   = {true,  true,  true,  true,  true,  true,  true,  true}
  29
  30 local function board_to_table(inv)
  31         local t = {}
  32         for i = 1, 64 do
  33                 t[#t + 1] = inv:get_stack("board", i):get_name()
  34         end
  35
  36         return t
  37 end
  38
  39 local function attacked(color, idx, board)
  40         local threatDetected = false
  41         local kill           = color == "white"
  42         local pawnThreats    = {kill, false, kill, false, false, not kill, false, not kill}
  43
  44         for dir = 1, 8 do
  45                 if not threatDetected then
  46                         local col, row = index_to_xy(idx)
  47                         col, row = col + 1, row + 1
  48
  49                         for step = 1, 8 do
  50                                 row = row + rowDirs[dir]
  51                                 col = col + colDirs[dir]
  52
  53                                 if row >= 1 and row <= 8 and col >= 1 and col <= 8 then
  54                                         local square            = get_square(row, col)
  55                                         local square_name       = board[square]
  56                                         local piece, pieceColor = square_name:match(":(%w+)_(%w+)")
  57
  58                                         if piece then
  59                                                 if pieceColor ~= color then
  60                                                         if piece == "bishop" and bishopThreats[dir] then
  61                                                                 threatDetected = true
  62                                                         elseif piece == "rook" and rookThreats[dir] then
  63                                                                 threatDetected = true
  64                                                         elseif piece == "queen" and queenThreats[dir] then
  65                                                                 threatDetected = true
  66                                                         else
  67                                                                 if step == 1 then
  68                                                                         if piece == "pawn" and pawnThreats[dir] then
  69                                                                                 threatDetected = true
  70                                                                         end
  71                                                                         if piece == "king" and kingThreats[dir] then
  72                                                                                 threatDetected = true
  73                                                                         end
  74                                                                 end
  75                                                         end
  76                                                 end
  77                                                 break
  78                                         end
  79                                 end
  80                         end
  81                 end
  82         end
  83
  84         return threatDetected
  85 end
  86
  87 local function locate_kings(board)
  88         local Bidx, Widx
  89         for i = 1, 64 do
  90                 local piece, color = board[i]:match(":(%w+)_(%w+)")
  91                 if piece == "king" then
  92                         if color == "black" then
  93                                 Bidx = i
  94                         else
  95                                 Widx = i
  96                         end
  97                 end
  98         end
  99
 100         return Bidx, Widx
 101 end
 102
 103 local pieces = {
 104         "realchess:rook_black_1",
 105         "realchess:knight_black_1",
 106         "realchess:bishop_black_1",
 107         "realchess:queen_black",
 108         "realchess:king_black",
 109         "realchess:bishop_black_2",
 110         "realchess:knight_black_2",
 111         "realchess:rook_black_2",
 112         "realchess:pawn_black_1",
 113         "realchess:pawn_black_2",
 114         "realchess:pawn_black_3",
 115         "realchess:pawn_black_4",
 116         "realchess:pawn_black_5",
 117         "realchess:pawn_black_6",
 118         "realchess:pawn_black_7",
 119         "realchess:pawn_black_8",
 120         '','','','','','','','','','','','','','','','',
 121         '','','','','','','','','','','','','','','','',
 122         "realchess:pawn_white_1",
 123         "realchess:pawn_white_2",
 124         "realchess:pawn_white_3",
 125         "realchess:pawn_white_4",
 126         "realchess:pawn_white_5",
 127         "realchess:pawn_white_6",
 128         "realchess:pawn_white_7",
 129         "realchess:pawn_white_8",
 130         "realchess:rook_white_1",
 131         "realchess:knight_white_1",
 132         "realchess:bishop_white_1",
 133         "realchess:queen_white",
 134         "realchess:king_white",
 135         "realchess:bishop_white_2",
 136         "realchess:knight_white_2",
 137         "realchess:rook_white_2"
 138 }
 139
 140 local pieces_str, x = "", 0
 141 for i = 1, #pieces do
 142         local p = pieces[i]:match(":(%w+_%w+)")
 143         if pieces[i]:find(":(%w+)_(%w+)") and not pieces_str:find(p) then
 144                 pieces_str = pieces_str .. x .. "=" .. p .. ".png,"
 145                 x = x + 1
 146         end
 147 end
 148 pieces_str = pieces_str .. "69=mailbox_blank16.png"
 149
 150 local fs = [[
 151         size[14.7,10;]
 152         no_prepend[]
 153         bgcolor[#080808BB;true]
 154         background[0,0;14.7,10;chess_bg.png]
 155         list[context;board;0.3,1;8,8;]
 156         listcolors[#00000000;#00000000;#00000000;#30434C;#FFF]
 157         tableoptions[background=#00000000;highlight=#00000000;border=false]
 158         button[10.5,8.5;2,2;new;New game]
 159 ]] ..  "tablecolumns[image," .. pieces_str ..
 160                 ";text;color;text;color;text;image," .. pieces_str .. "]"
 161
 162 local function get_moves_list(meta, pieceFrom, pieceTo, pieceTo_s, from_x, to_x, from_y, to_y)
 163         local moves           = meta:get_string("moves")
 164         local pieceFrom_s     = pieceFrom:match(":(%w+_%w+)")
 165         local pieceFrom_si_id = pieces_str:match("(%d+)=" .. pieceFrom_s)
 166         local pieceTo_si_id   = pieceTo_s ~= "" and pieces_str:match("(%d+)=" .. pieceTo_s) or ""
 167
 168         local coordFrom = letters[from_x + 1] .. math.abs(from_y - 8)
 169         local coordTo   = letters[to_x   + 1] .. math.abs(to_y   - 8)
 170
 171         local new_moves = pieceFrom_si_id .. "," ..
 172                 coordFrom .. "," ..
 173                         (pieceTo ~= "" and "#33FF33" or "#FFFFFF") .. ", > ,#FFFFFF," ..
 174                 coordTo .. "," ..
 175                 (pieceTo ~= "" and pieceTo_si_id or "69") .. "," ..
 176                 moves
 177
 178         meta:set_string("moves", new_moves)
 179 end
 180
 181 local function get_eaten_list(meta, pieceTo, pieceTo_s)
 182         local eaten = meta:get_string("eaten")
 183         if pieceTo ~= "" then
 184                 eaten = eaten .. pieceTo_s .. ","
 185         end
 186
 187         meta:set_string("eaten", eaten)
 188
 189         local eaten_t   = string.split(eaten, ",")
 190         local eaten_img = ""
 191
 192         local a, b = 0, 0
 193         for i = 1, #eaten_t do
 194                 local is_white = eaten_t[i]:sub(-5,-1) == "white"
 195                 local X = (is_white and a or b) % 4
 196                 local Y = ((is_white and a or b) % 16 - X) / 4
 197
 198                 if is_white then
 199                         a = a + 1
 200                 else
 201                         b = b + 1
 202                 end
 203
 204                 eaten_img = eaten_img ..
 205                         "image[" .. ((X + (is_white and 11.7 or 8.8)) - (X * 0.45)) .. "," ..
 206                                     ((Y + 5.56) - (Y * 0.2)) .. ";1,1;" .. eaten_t[i] .. ".png]"
 207         end
 208
 209         meta:set_string("eaten_img", eaten_img)
 210 end
 211
 212 function realchess.init(pos)
 213         local meta = minetest.get_meta(pos)
 214         local inv  = meta:get_inventory()
 215
 216         meta:set_string("formspec", fs)
 217         meta:set_string("infotext", "Chess Board")
 218         meta:set_string("playerBlack", "")
 219         meta:set_string("playerWhite", "")
 220         meta:set_string("lastMove",    "")
 221         meta:set_string("blackAttacked", "")
 222         meta:set_string("whiteAttacked", "")
 223
 224         meta:set_int("lastMoveTime",   0)
 225         meta:set_int("castlingBlackL", 1)
 226         meta:set_int("castlingBlackR", 1)
 227         meta:set_int("castlingWhiteL", 1)
 228         meta:set_int("castlingWhiteR", 1)
 229
 230         meta:set_string("moves", "")
 231         meta:set_string("eaten", "")
 232
 233         inv:set_list("board", pieces)
 234         inv:set_size("board", 64)
 235 end
 236
 237 function realchess.move(pos, from_list, from_index, to_list, to_index, _, player)
 238         if from_list ~= "board" and to_list ~= "board" then
 239                 return 0
 240         end
 241
 242         local meta        = minetest.get_meta(pos)
 243         local playerName  = player:get_player_name()
 244         local inv         = meta:get_inventory()
 245         local pieceFrom   = inv:get_stack(from_list, from_index):get_name()
 246         local pieceTo     = inv:get_stack(to_list, to_index):get_name()
 247         local lastMove    = meta:get_string("lastMove")
 248         local playerWhite = meta:get_string("playerWhite")
 249         local playerBlack = meta:get_string("playerBlack")
 250         local thisMove    -- Will replace lastMove when move is legal
 251
 252         if pieceFrom:find("white") then
 253                 if playerWhite ~= "" and playerWhite ~= playerName then
 254                         minetest.chat_send_player(playerName, chat_prefix .. "Someone else plays white pieces!")
 255                         return 0
 256                 end
 257
 258                 if lastMove ~= "" and lastMove ~= "black" then
 259                         return 0
 260                 end
 261
 262                 if pieceTo:find("white") then
 263                         -- Don't replace pieces of same color
 264                         return 0
 265                 end
 266
 267                 playerWhite = playerName
 268                 thisMove = "white"
 269
 270         elseif pieceFrom:find("black") then
 271                 if playerBlack ~= "" and playerBlack ~= playerName then
 272                         minetest.chat_send_player(playerName, chat_prefix .. "Someone else plays black pieces!")
 273                         return 0
 274                 end
 275
 276                 if lastMove ~= "" and lastMove ~= "white" then
 277                         return 0
 278                 end
 279
 280                 if pieceTo:find("black") then
 281                         -- Don't replace pieces of same color
 282                         return 0
 283                 end
 284
 285                 playerBlack = playerName
 286                 thisMove = "black"
 287         end
 288
 289         -- MOVE LOGIC
 290
 291         local from_x, from_y = index_to_xy(from_index)
 292         local to_x, to_y     = index_to_xy(to_index)
 293
 294         -- PAWN
 295         if pieceFrom:sub(11,14) == "pawn" then
 296                 if thisMove == "white" then
 297                         local pawnWhiteMove = inv:get_stack(from_list, xy_to_index(from_x, from_y - 1)):get_name()
 298                         -- white pawns can go up only
 299                         if from_y - 1 == to_y then
 300                                 if from_x == to_x then
 301                                         if pieceTo ~= "" then
 302                                                 return 0
 303                                         elseif to_index >= 1 and to_index <= 8 then
 304                                                 inv:set_stack(from_list, from_index, "realchess:queen_white")
 305                                         end
 306                                 elseif from_x - 1 == to_x or from_x + 1 == to_x then
 307                                         if not pieceTo:find("black") then
 308                                                 return 0
 309                                         elseif to_index >= 1 and to_index <= 8 then
 310                                                 inv:set_stack(from_list, from_index, "realchess:queen_white")
 311                                         end
 312                                 else
 313                                         return 0
 314                                 end
 315                         elseif from_y - 2 == to_y then
 316                                 if pieceTo ~= "" or from_y < 6 or pawnWhiteMove ~= "" then
 317                                         return 0
 318                                 end
 319                         else
 320                                 return 0
 321                         end
 322
 323                         --[[
 324                              if x not changed
 325                                   ensure that destination cell is empty
 326                              elseif x changed one unit left or right
 327                                   ensure the pawn is killing opponent piece
 328                              else
 329                                   move is not legal - abort
 330                         ]]
 331
 332                         if from_x == to_x then
 333                                 if pieceTo ~= "" then
 334                                         return 0
 335                                 end
 336                         elseif from_x - 1 == to_x or from_x + 1 == to_x then
 337                                 if not pieceTo:find("black") then
 338                                         return 0
 339                                 end
 340                         else
 341                                 return 0
 342                         end
 343
 344                 elseif thisMove == "black" then
 345                         local pawnBlackMove = inv:get_stack(from_list, xy_to_index(from_x, from_y + 1)):get_name()
 346                         -- black pawns can go down only
 347                         if from_y + 1 == to_y then
 348                                 if from_x == to_x then
 349                                         if pieceTo ~= "" then
 350                                                 return 0
 351                                         elseif to_index >= 57 and to_index <= 64 then
 352                                                 inv:set_stack(from_list, from_index, "realchess:queen_black")
 353                                         end
 354                                 elseif from_x - 1 == to_x or from_x + 1 == to_x then
 355                                         if not pieceTo:find("white") then
 356                                                 return 0
 357                                         elseif to_index >= 57 and to_index <= 64 then
 358                                                 inv:set_stack(from_list, from_index, "realchess:queen_black")
 359                                         end
 360                                 else
 361                                         return 0
 362                                 end
 363                         elseif from_y + 2 == to_y then
 364                                 if pieceTo ~= "" or from_y > 1 or pawnBlackMove ~= "" then
 365                                         return 0
 366                                 end
 367                         else
 368                                 return 0
 369                         end
 370
 371                         --[[
 372                              if x not changed
 373                                   ensure that destination cell is empty
 374                              elseif x changed one unit left or right
 375                                   ensure the pawn is killing opponent piece
 376                              else
 377                                   move is not legal - abort
 378                         ]]
 379
 380                         if from_x == to_x then
 381                                 if pieceTo ~= "" then
 382                                         return 0
 383                                 end
 384                         elseif from_x - 1 == to_x or from_x + 1 == to_x then
 385                                 if not pieceTo:find("white") then
 386                                         return 0
 387                                 end
 388                         else
 389                                 return 0
 390                         end
 391                 else
 392                         return 0
 393                 end
 394
 395         -- ROOK
 396         elseif pieceFrom:sub(11,14) == "rook" then
 397                 if from_x == to_x then
 398                         -- Moving vertically
 399                         if from_y < to_y then
 400                                 -- Moving down
 401                                 -- Ensure that no piece disturbs the way
 402                                 for i = from_y + 1, to_y - 1 do
 403                                         if inv:get_stack(from_list, xy_to_index(from_x, i)):get_name() ~= "" then
 404                                                 return 0
 405                                         end
 406                                 end
 407                         else
 408                                 -- Mocing up
 409                                 -- Ensure that no piece disturbs the way
 410                                 for i = to_y + 1, from_y - 1 do
 411                                         if inv:get_stack(from_list, xy_to_index(from_x, i)):get_name() ~= "" then
 412                                                 return 0
 413                                         end
 414                                 end
 415                         end
 416                 elseif from_y == to_y then
 417                         -- Mocing horizontally
 418                         if from_x < to_x then
 419                                 -- mocing right
 420                                 -- ensure that no piece disturbs the way
 421                                 for i = from_x + 1, to_x - 1 do
 422                                         if inv:get_stack(from_list, xy_to_index(i, from_y)):get_name() ~= "" then
 423                                                 return 0
 424                                         end
 425                                 end
 426                         else
 427                                 -- Mocing left
 428                                 -- Ensure that no piece disturbs the way
 429                                 for i = to_x + 1, from_x - 1 do
 430                                         if inv:get_stack(from_list, xy_to_index(i, from_y)):get_name() ~= "" then
 431                                                 return 0
 432                                         end
 433                                 end
 434                         end
 435                 else
 436                         -- Attempt to move arbitrarily -> abort
 437                         return 0
 438                 end
 439
 440                 if thisMove == "white" or thisMove == "black" then
 441                         if pieceFrom:sub(-1) == "1" then
 442                                 meta:set_int("castlingWhiteL", 0)
 443                         elseif pieceFrom:sub(-1) == "2" then
 444                                 meta:set_int("castlingWhiteR", 0)
 445                         end
 446                 end
 447
 448         -- KNIGHT
 449         elseif pieceFrom:sub(11,16) == "knight" then
 450                 -- Get relative pos
 451                 local dx = from_x - to_x
 452                 local dy = from_y - to_y
 453
 454                 -- Get absolute values
 455                 if dx < 0 then dx = -dx end
 456                 if dy < 0 then dy = -dy end
 457
 458                 -- Sort x and y
 459                 if dx > dy then dx, dy = dy, dx end
 460
 461                 -- Ensure that dx == 1 and dy == 2
 462                 if dx ~= 1 or dy ~= 2 then
 463                         return 0
 464                 end
 465                 -- Just ensure that destination cell does not contain friend piece
 466                 -- ^ It was done already thus everything ok
 467
 468         -- BISHOP
 469         elseif pieceFrom:sub(11,16) == "bishop" then
 470                 -- Get relative pos
 471                 local dx = from_x - to_x
 472                 local dy = from_y - to_y
 473
 474                 -- Get absolute values
 475                 if dx < 0 then dx = -dx end
 476                 if dy < 0 then dy = -dy end
 477
 478                 -- Ensure dx and dy are equal
 479                 if dx ~= dy then return 0 end
 480
 481                 if from_x < to_x then
 482                         if from_y < to_y then
 483                                 -- Moving right-down
 484                                 -- Ensure that no piece disturbs the way
 485                                 for i = 1, dx - 1 do
 486                                         if inv:get_stack(from_list, xy_to_index(from_x + i, from_y + i)):get_name() ~= "" then
 487                                                 return 0
 488                                         end
 489                                 end
 490                         else
 491                                 -- Moving right-up
 492                                 -- Ensure that no piece disturbs the way
 493                                 for i = 1, dx - 1 do
 494                                         if inv:get_stack(from_list, xy_to_index(from_x + i, from_y - i)):get_name() ~= "" then
 495                                                 return 0
 496                                         end
 497                                 end
 498                         end
 499                 else
 500                         if from_y < to_y then
 501                                 -- Moving left-down
 502                                 -- Ensure that no piece disturbs the way
 503                                 for i = 1, dx - 1 do
 504                                         if inv:get_stack(from_list, xy_to_index(from_x - i, from_y + i)):get_name() ~= "" then
 505                                                 return 0
 506                                         end
 507                                 end
 508                         else
 509                                 -- Moving left-up
 510                                 -- ensure that no piece disturbs the way
 511                                 for i = 1, dx - 1 do
 512                                         if inv:get_stack(from_list, xy_to_index(from_x - i, from_y - i)):get_name() ~= "" then
 513                                                 return 0
 514                                         end
 515                                 end
 516                         end
 517                 end
 518
 519         -- QUEEN
 520         elseif pieceFrom:sub(11,15) == "queen" then
 521                 local dx = from_x - to_x
 522                 local dy = from_y - to_y
 523
 524                 -- Get absolute values
 525                 if dx < 0 then dx = -dx end
 526                 if dy < 0 then dy = -dy end
 527
 528                 -- Ensure valid relative move
 529                 if dx ~= 0 and dy ~= 0 and dx ~= dy then
 530                         return 0
 531                 end
 532
 533                 if from_x == to_x then
 534                         if from_y < to_y then
 535                                 -- Goes down
 536                                 -- Ensure that no piece disturbs the way
 537                                 for i = 1, dx - 1 do
 538                                         if inv:get_stack(from_list, xy_to_index(from_x, from_y + i)):get_name() ~= "" then
 539                                                 return 0
 540                                         end
 541                                 end
 542                         else
 543                                 -- Goes up
 544                                 -- Ensure that no piece disturbs the way
 545                                 for i = 1, dx - 1 do
 546                                         if inv:get_stack(from_list, xy_to_index(from_x, from_y - i)):get_name() ~= "" then
 547                                                 return 0
 548                                         end
 549                                 end
 550                         end
 551                 elseif from_x < to_x then
 552                         if from_y == to_y then
 553                                 -- Goes right
 554                                 -- Ensure that no piece disturbs the way
 555                                 for i = 1, dx - 1 do
 556                                         if inv:get_stack(from_list, xy_to_index(from_x + i, from_y)):get_name() ~= "" then
 557                                                 return 0
 558                                         end
 559                                 end
 560                         elseif from_y < to_y then
 561                                 -- Goes right-down
 562                                 -- Ensure that no piece disturbs the way
 563                                 for i = 1, dx - 1 do
 564                                         if inv:get_stack(from_list, xy_to_index(from_x + i, from_y + i)):get_name() ~= "" then
 565                                                 return 0
 566                                         end
 567                                 end
 568                         else
 569                                 -- Goes right-up
 570                                 -- Ensure that no piece disturbs the way
 571                                 for i = 1, dx - 1 do
 572                                         if inv:get_stack(from_list, xy_to_index(from_x + i, from_y - i)):get_name() ~= "" then
 573                                                 return 0
 574                                         end
 575                                 end
 576                         end
 577                 else
 578                         if from_y == to_y then
 579                                 -- Goes left
 580                                 -- Ensure that no piece disturbs the way and destination cell does
 581                                 for i = 1, dx - 1 do
 582                                         if inv:get_stack(from_list, xy_to_index(from_x - i, from_y)):get_name() ~= "" then
 583                                                 return 0
 584                                         end
 585                                 end
 586                         elseif from_y < to_y then
 587                                 -- Goes left-down
 588                                 -- Ensure that no piece disturbs the way
 589                                 for i = 1, dx - 1 do
 590                                         if inv:get_stack(from_list, xy_to_index(from_x - i, from_y + i)):get_name() ~= "" then
 591                                                 return 0
 592                                         end
 593                                 end
 594                         else
 595                                 -- Goes left-up
 596                                 -- Ensure that no piece disturbs the way
 597                                 for i = 1, dx - 1 do
 598                                         if inv:get_stack(from_list, xy_to_index(from_x - i, from_y - i)):get_name() ~= "" then
 599                                                 return 0
 600                                         end
 601                                 end
 602                         end
 603                 end
 604
 605         -- KING
 606         elseif pieceFrom:sub(11,14) == "king" then
 607                 local dx = from_x - to_x
 608                 local dy = from_y - to_y
 609                 local check = true
 610
 611                 if thisMove == "white" then
 612                         if from_y == 7 and to_y == 7 then
 613                                 if to_x == 1 then
 614                                         local castlingWhiteL = meta:get_int("castlingWhiteL")
 615                                         local idx57 = inv:get_stack(from_list, 57):get_name()
 616
 617                                         if castlingWhiteL == 1 and idx57 == "realchess:rook_white_1" then
 618                                                 for i = 58, from_index - 1 do
 619                                                         if inv:get_stack(from_list, i):get_name() ~= "" then
 620                                                                 return 0
 621                                                         end
 622                                                 end
 623                                                 inv:set_stack(from_list, 57, "")
 624                                                 inv:set_stack(from_list, 59, "realchess:rook_white_1")
 625                                                 check = false
 626                                         end
 627                                 elseif to_x == 6 then
 628                                         local castlingWhiteR = meta:get_int("castlingWhiteR")
 629                                         local idx64 = inv:get_stack(from_list, 64):get_name()
 630
 631                                         if castlingWhiteR == 1 and idx64 == "realchess:rook_white_2" then
 632                                                 for i = from_index + 1, 63 do
 633                                                         if inv:get_stack(from_list, i):get_name() ~= "" then
 634                                                                 return 0
 635                                                         end
 636                                                 end
 637                                                 inv:set_stack(from_list, 62, "realchess:rook_white_2")
 638                                                 inv:set_stack(from_list, 64, "")
 639                                                 check = false
 640                                         end
 641                                 end
 642                         end
 643                 elseif thisMove == "black" then
 644                         if from_y == 0 and to_y == 0 then
 645                                 if to_x == 1 then
 646                                         local castlingBlackL = meta:get_int("castlingBlackL")
 647                                         local idx1 = inv:get_stack(from_list, 1):get_name()
 648
 649                                         if castlingBlackL == 1 and idx1 == "realchess:rook_black_1" then
 650                                                 for i = 2, from_index - 1 do
 651                                                         if inv:get_stack(from_list, i):get_name() ~= "" then
 652                                                                 return 0
 653                                                         end
 654                                                 end
 655
 656                                                 inv:set_stack(from_list, 1, "")
 657                                                 inv:set_stack(from_list, 3, "realchess:rook_black_1")
 658                                                 check = false
 659                                         end
 660                                 elseif to_x == 6 then
 661                                         local castlingBlackR = meta:get_int("castlingBlackR")
 662                                         local idx8 = inv:get_stack(from_list, 1):get_name()
 663
 664                                         if castlingBlackR == 1 and idx8 == "realchess:rook_black_2" then
 665                                                 for i = from_index + 1, 7 do
 666                                                         if inv:get_stack(from_list, i):get_name() ~= "" then
 667                                                                 return 0
 668                                                         end
 669                                                 end
 670
 671                                                 inv:set_stack(from_list, 6, "realchess:rook_black_2")
 672                                                 inv:set_stack(from_list, 8, "")
 673                                                 check = false
 674                                         end
 675                                 end
 676                         end
 677                 end
 678
 679                 if check then
 680                         if dx < 0 then
 681                                 dx = -dx
 682                         end
 683
 684                         if dy < 0 then
 685                                 dy = -dy
 686                         end
 687
 688                         if dx > 1 or dy > 1 then
 689                                 return 0
 690                         end
 691                 end
 692
 693                 if thisMove == "white" then
 694                         meta:set_int("castlingWhiteL", 0)
 695                         meta:set_int("castlingWhiteR", 0)
 696
 697                 elseif thisMove == "black" then
 698                         meta:set_int("castlingBlackL", 0)
 699                         meta:set_int("castlingBlackR", 0)
 700                 end
 701         end
 702
 703         local board       = board_to_table(inv)
 704         board[to_index]   = board[from_index]
 705         board[from_index] = ""
 706
 707         local black_king_idx, white_king_idx = locate_kings(board)
 708         local blackAttacked = attacked("black", black_king_idx, board)
 709         local whiteAttacked = attacked("white", white_king_idx, board)
 710
 711         if blackAttacked then
 712                 if thisMove == "black" and meta:get_string("blackAttacked") == "true" then
 713                         return 0
 714                 else
 715                         meta:set_string("blackAttacked", "true")
 716                 end
 717         else
 718                 meta:set_string("blackAttacked", "")
 719         end
 720
 721         if whiteAttacked then
 722                 if thisMove == "white" and meta:get_string("whiteAttacked") == "true" then
 723                         return 0
 724                 else
 725                         meta:set_string("whiteAttacked", "true")
 726                 end
 727         else
 728                 meta:set_string("whiteAttacked", "")
 729         end
 730
 731         lastMove = thisMove
 732
 733         meta:set_string("lastMove", lastMove)
 734         meta:set_int("lastMoveTime", minetest.get_gametime())
 735         meta:set_string("playerWhite", playerWhite)
 736         meta:set_string("playerBlack", playerBlack)
 737
 738         local pieceTo_s = pieceTo ~= "" and pieceTo:match(":(%w+_%w+)") or ""
 739         get_moves_list(meta, pieceFrom, pieceTo, pieceTo_s, from_x, to_x, from_y, to_y)
 740         get_eaten_list(meta, pieceTo, pieceTo_s)
 741
 742         return 1
 743 end
 744
 745 function realchess.on_move(pos, from_list, from_index)
 746         local meta = minetest.get_meta(pos)
 747         local inv  = meta:get_inventory()
 748         inv:set_stack(from_list, from_index, '')
 749
 750         local black_king_attacked = meta:get_string("blackAttacked") == "true"
 751         local white_king_attacked = meta:get_string("whiteAttacked") == "true"
 752
 753         local playerWhite = meta:get_string("playerWhite")
 754         local playerBlack = meta:get_string("playerBlack")
 755
 756         local moves       = meta:get_string("moves")
 757         local eaten_img   = meta:get_string("eaten_img")
 758         local lastMove    = meta:get_string("lastMove")
 759         local turnBlack   = minetest.colorize("#000001", (lastMove == "white" and playerBlack ~= "") and
 760                             playerBlack .. "..." or playerBlack)
 761         local turnWhite   = minetest.colorize("#000001", (lastMove == "black" and playerWhite ~= "") and
 762                             playerWhite .. "..." or playerWhite)
 763         local check_s     = minetest.colorize("#FF0000", "\\[check\\]")
 764
 765         local formspec = fs ..
 766                 "label[1.9,0.3;"  .. turnBlack .. (black_king_attacked and " " .. check_s or "") .. "]" ..
 767                 "label[1.9,9.15;" .. turnWhite .. (white_king_attacked and " " .. check_s or "") .. "]" ..
 768                 "table[8.9,1.05;5.07,3.75;moves;" .. moves:sub(1,-2) .. ";1]" ..
 769                 eaten_img
 770
 771         meta:set_string("formspec", formspec)
 772
 773         return false
 774 end
 775
 776 local function timeout_format(timeout_limit)
 777         local time_remaining = timeout_limit - minetest.get_gametime()
 778         local minutes        = math.floor(time_remaining / 60)
 779         local seconds        = time_remaining % 60
 780
 781         if minutes == 0 then
 782                 return seconds .. " sec."
 783         end
 784
 785         return minutes .. " min. " .. seconds .. " sec."
 786 end
 787
 788 function realchess.fields(pos, _, fields, sender)
 789         local playerName    = sender:get_player_name()
 790         local meta          = minetest.get_meta(pos)
 791         local timeout_limit = meta:get_int("lastMoveTime") + 300
 792         local playerWhite   = meta:get_string("playerWhite")
 793         local playerBlack   = meta:get_string("playerBlack")
 794         local lastMoveTime  = meta:get_int("lastMoveTime")
 795         if fields.quit then return end
 796
 797         -- Timeout is 5 min. by default for resetting the game (non-players only)
 798         if fields.new then
 799                 if (playerWhite == playerName or playerBlack == playerName) then
 800                         realchess.init(pos)
 801
 802                 elseif lastMoveTime ~= 0 then
 803                         if minetest.get_gametime() >= timeout_limit and
 804                                         (playerWhite ~= playerName or playerBlack ~= playerName) then
 805                                 realchess.init(pos)
 806                         else
 807                                 minetest.chat_send_player(playerName, chat_prefix ..
 808                                         "You can't reset the chessboard, a game has been started. " ..
 809                                         "If you aren't a current player, try again in " ..
 810                                         timeout_format(timeout_limit))
 811                         end
 812                 end
 813         end
 814 end
 815
 816 function realchess.dig(pos, player)
 817         if not player then
 818                 return false
 819         end
 820
 821         local meta          = minetest.get_meta(pos)
 822         local playerName    = player:get_player_name()
 823         local timeout_limit = meta:get_int("lastMoveTime") + 300
 824         local lastMoveTime  = meta:get_int("lastMoveTime")
 825
 826         -- Timeout is 5 min. by default for digging the chessboard (non-players only)
 827         return (lastMoveTime == 0 and minetest.get_gametime() > timeout_limit) or
 828                 minetest.chat_send_player(playerName, chat_prefix ..
 829                                 "You can't dig the chessboard, a game has been started. " ..
 830                                 "Reset it first if you're a current player, or dig it again in " ..
 831                                 timeout_format(timeout_limit))
 832 end
 833
 834 minetest.register_node(":realchess:chessboard", {
 835         description = "Chess Board",
 836         drawtype = "nodebox",
 837         paramtype = "light",
 838         paramtype2 = "facedir",
 839         inventory_image = "chessboard_top.png",
 840         wield_image = "chessboard_top.png",
 841         tiles = {"chessboard_top.png", "chessboard_top.png", "chessboard_sides.png"},
 842         groups = {choppy=3, oddly_breakable_by_hand=2, flammable=3},
 843         sounds = default.node_sound_wood_defaults(),
 844         node_box = {type = "fixed", fixed = {-.375, -.5, -.375, .375, -.4375, .375}},
 845         sunlight_propagates = true,
 846         on_rotate = screwdriver.rotate_simple,
 847         can_dig = realchess.dig,
 848         on_construct = realchess.init,
 849         on_receive_fields = realchess.fields,
 850         allow_metadata_inventory_move = realchess.move,
 851         on_metadata_inventory_move = realchess.on_move,
 852         allow_metadata_inventory_take = function() return 0 end
 853 })
 854
 855 local function register_piece(name, count)
 856         for _, color in pairs({"black", "white"}) do
 857         if not count then
 858                 minetest.register_craftitem(":realchess:" .. name .. "_" .. color, {
 859                         description = color:gsub("^%l", string.upper) .. " " .. name:gsub("^%l", string.upper),
 860                         inventory_image = name .. "_" .. color .. ".png",
 861                         stack_max = 1,
 862                         groups = {not_in_creative_inventory=1}
 863                 })
 864         else
 865                 for i = 1, count do
 866                         minetest.register_craftitem(":realchess:" .. name .. "_" .. color .. "_" .. i, {
 867                                 description = color:gsub("^%l", string.upper) .. " " .. name:gsub("^%l", string.upper),
 868                                 inventory_image = name .. "_" .. color .. ".png",
 869                                 stack_max = 1,
 870                                 groups = {not_in_creative_inventory=1}
 871                         })
 872                 end
 873         end
 874         end
 875 end
 876
 877 register_piece("pawn", 8)
 878 register_piece("rook", 2)
 879 register_piece("knight", 2)
 880 register_piece("bishop", 2)
 881 register_piece("queen")
 882 register_piece("king")
 883
 884 -- Recipes
 885
 886 minetest.register_craft({
 887         output = "realchess:chessboard",
 888         recipe = {
 889                 {"dye:black", "dye:white", "dye:black"},
 890                 {"stairs:slab_wood", "stairs:slab_wood", "stairs:slab_wood"}
 891         }
 892 })