Wed, 29 Aug 2018 15:12:24 +0200
fixes ambiguity resolver in PGN output not resolving ambiguities for diagonally attacking Knights
universe@19 | 1 | /* |
universe@19 | 2 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER. |
universe@19 | 3 | * |
universe@55 | 4 | * Copyright 2016 Mike Becker. All rights reserved. |
universe@19 | 5 | * |
universe@19 | 6 | * Redistribution and use in source and binary forms, with or without |
universe@19 | 7 | * modification, are permitted provided that the following conditions are met: |
universe@19 | 8 | * |
universe@19 | 9 | * 1. Redistributions of source code must retain the above copyright |
universe@19 | 10 | * notice, this list of conditions and the following disclaimer. |
universe@19 | 11 | * |
universe@19 | 12 | * 2. Redistributions in binary form must reproduce the above copyright |
universe@19 | 13 | * notice, this list of conditions and the following disclaimer in the |
universe@19 | 14 | * documentation and/or other materials provided with the distribution. |
universe@19 | 15 | * |
universe@19 | 16 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
universe@19 | 17 | * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
universe@19 | 18 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
universe@19 | 19 | * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE |
universe@19 | 20 | * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
universe@19 | 21 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
universe@19 | 22 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
universe@19 | 23 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
universe@19 | 24 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
universe@19 | 25 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
universe@19 | 26 | * POSSIBILITY OF SUCH DAMAGE. |
universe@19 | 27 | * |
universe@19 | 28 | */ |
universe@19 | 29 | |
universe@19 | 30 | #include "rules.h" |
universe@19 | 31 | #include "chess.h" |
universe@19 | 32 | #include <string.h> |
universe@23 | 33 | #include <stdlib.h> |
universe@36 | 34 | #include <sys/time.h> |
universe@23 | 35 | |
universe@48 | 36 | static GameState gamestate_copy_sim(GameState *gamestate) { |
universe@48 | 37 | GameState simulation = *gamestate; |
universe@66 | 38 | simulation.movecount = 0; /* simulations do not count moves */ |
universe@48 | 39 | if (simulation.lastmove) { |
universe@48 | 40 | MoveList *lastmovecopy = malloc(sizeof(MoveList)); |
universe@48 | 41 | *lastmovecopy = *(simulation.lastmove); |
universe@48 | 42 | simulation.movelist = simulation.lastmove = lastmovecopy; |
universe@48 | 43 | } |
universe@51 | 44 | |
universe@48 | 45 | return simulation; |
universe@48 | 46 | } |
universe@48 | 47 | |
universe@50 | 48 | void gamestate_init(GameState *gamestate) { |
universe@50 | 49 | memset(gamestate, 0, sizeof(GameState)); |
universe@50 | 50 | |
universe@50 | 51 | Board initboard = { |
universe@50 | 52 | {WROOK, WKNIGHT, WBISHOP, WQUEEN, WKING, WBISHOP, WKNIGHT, WROOK}, |
universe@50 | 53 | {WPAWN, WPAWN, WPAWN, WPAWN, WPAWN, WPAWN, WPAWN, WPAWN}, |
universe@50 | 54 | {0, 0, 0, 0, 0, 0, 0, 0}, |
universe@50 | 55 | {0, 0, 0, 0, 0, 0, 0, 0}, |
universe@50 | 56 | {0, 0, 0, 0, 0, 0, 0, 0}, |
universe@50 | 57 | {0, 0, 0, 0, 0, 0, 0, 0}, |
universe@50 | 58 | {BPAWN, BPAWN, BPAWN, BPAWN, BPAWN, BPAWN, BPAWN, BPAWN}, |
universe@50 | 59 | {BROOK, BKNIGHT, BBISHOP, BQUEEN, BKING, BBISHOP, BKNIGHT, BROOK} |
universe@50 | 60 | }; |
universe@50 | 61 | memcpy(gamestate->board, initboard, sizeof(Board)); |
universe@50 | 62 | } |
universe@50 | 63 | |
universe@23 | 64 | void gamestate_cleanup(GameState *gamestate) { |
universe@23 | 65 | MoveList *elem; |
universe@23 | 66 | elem = gamestate->movelist; |
universe@23 | 67 | while (elem) { |
universe@23 | 68 | MoveList *cur = elem; |
universe@23 | 69 | elem = elem->next; |
universe@23 | 70 | free(cur); |
universe@23 | 71 | }; |
universe@23 | 72 | } |
universe@23 | 73 | |
universe@66 | 74 | /* MUST be called BEFORE applying a move to work correctly */ |
universe@49 | 75 | static void format_move(GameState *gamestate, Move *move) { |
universe@66 | 76 | char *string = &(move->string[0]); |
universe@49 | 77 | |
universe@49 | 78 | /* at least 8 characters should be available, wipe them out */ |
universe@49 | 79 | memset(string, 0, 8); |
universe@49 | 80 | |
universe@64 | 81 | unsigned int idx; |
universe@49 | 82 | if ((move->piece&PIECE_MASK) == KING && |
universe@49 | 83 | abs(move->tofile-move->fromfile) == 2) { |
universe@64 | 84 | /* special formats for castling */ |
universe@49 | 85 | if (move->tofile==fileidx('c')) { |
universe@49 | 86 | memcpy(string, "O-O-O", 5); |
universe@64 | 87 | idx = 5; |
universe@49 | 88 | } else { |
universe@49 | 89 | memcpy(string, "O-O", 3); |
universe@64 | 90 | idx = 3; |
universe@49 | 91 | } |
universe@64 | 92 | } else { |
universe@64 | 93 | /* start by notating the piece character */ |
universe@64 | 94 | string[0] = getpiecechr(move->piece); |
universe@64 | 95 | idx = string[0] ? 1 : 0; |
universe@49 | 96 | |
universe@64 | 97 | /* find out how many source information we do need */ |
universe@64 | 98 | uint8_t piece = move->piece & PIECE_MASK; |
universe@64 | 99 | if (piece == PAWN) { |
universe@64 | 100 | if (move->capture) { |
universe@64 | 101 | string[idx++] = filechr(move->fromfile); |
universe@64 | 102 | } |
universe@64 | 103 | } else if (piece != KING) { |
universe@64 | 104 | /* resolve ambiguities, if any */ |
universe@64 | 105 | Move threats[16]; |
universe@64 | 106 | uint8_t threatcount; |
universe@66 | 107 | if (get_threats(gamestate, move->torow, move->tofile, |
universe@66 | 108 | move->piece&COLOR_MASK, threats, &threatcount)) { |
universe@66 | 109 | unsigned int ambrows = 0, ambfiles = 0, ambpiece = 0; |
universe@64 | 110 | for (uint8_t i = 0 ; i < threatcount ; i++) { |
universe@66 | 111 | if (threats[i].piece == move->piece) { |
universe@66 | 112 | ambpiece++; |
universe@66 | 113 | if (threats[i].fromrow == move->fromrow) { |
universe@66 | 114 | ambrows++; |
universe@66 | 115 | } |
universe@66 | 116 | if (threats[i].fromfile == move->fromfile) { |
universe@66 | 117 | ambfiles++; |
universe@66 | 118 | } |
universe@64 | 119 | } |
universe@49 | 120 | } |
universe@66 | 121 | /* neither file, nor row are ambiguous, name file */ |
universe@66 | 122 | if (ambpiece > 1 && ambrows == 1 && ambfiles == 1) { |
universe@66 | 123 | /* this is most likely the case with Knights |
universe@66 | 124 | * in diagonal opposition */ |
universe@64 | 125 | string[idx++] = filechr(move->fromfile); |
universe@66 | 126 | } else { |
universe@66 | 127 | /* ambiguous row, name file */ |
universe@66 | 128 | if (ambrows > 1) { |
universe@66 | 129 | string[idx++] = filechr(move->fromfile); |
universe@66 | 130 | } |
universe@66 | 131 | /* ambiguous file, name row */ |
universe@66 | 132 | if (ambfiles > 1) { |
universe@66 | 133 | string[idx++] = filechr(move->fromrow); |
universe@66 | 134 | } |
universe@49 | 135 | } |
universe@49 | 136 | } |
universe@49 | 137 | } |
universe@64 | 138 | |
universe@64 | 139 | /* capturing? */ |
universe@64 | 140 | if (move->capture) { |
universe@64 | 141 | string[idx++] = 'x'; |
universe@64 | 142 | } |
universe@64 | 143 | |
universe@64 | 144 | /* destination */ |
universe@64 | 145 | string[idx++] = filechr(move->tofile); |
universe@64 | 146 | string[idx++] = rowchr(move->torow); |
universe@64 | 147 | |
universe@64 | 148 | /* promotion? */ |
universe@64 | 149 | if (move->promotion) { |
universe@64 | 150 | string[idx++] = '='; |
universe@64 | 151 | string[idx++] = getpiecechr(move->promotion); |
universe@64 | 152 | } |
universe@49 | 153 | } |
universe@49 | 154 | |
universe@49 | 155 | /* check? */ |
universe@49 | 156 | if (move->check) { |
universe@66 | 157 | // TODO: does not work, because checkmate is not set when format_move is called |
universe@49 | 158 | string[idx++] = gamestate->checkmate?'#':'+'; |
universe@49 | 159 | } |
universe@49 | 160 | } |
universe@49 | 161 | |
universe@23 | 162 | static void addmove(GameState* gamestate, Move *move) { |
universe@23 | 163 | MoveList *elem = malloc(sizeof(MoveList)); |
universe@23 | 164 | elem->next = NULL; |
universe@23 | 165 | elem->move = *move; |
universe@23 | 166 | |
universe@40 | 167 | struct timeval curtimestamp; |
universe@40 | 168 | gettimeofday(&curtimestamp, NULL); |
universe@40 | 169 | elem->move.timestamp.tv_sec = curtimestamp.tv_sec; |
universe@40 | 170 | elem->move.timestamp.tv_usec = curtimestamp.tv_usec; |
universe@33 | 171 | |
universe@23 | 172 | if (gamestate->lastmove) { |
universe@40 | 173 | struct movetimeval *lasttstamp = &(gamestate->lastmove->move.timestamp); |
universe@40 | 174 | uint64_t sec = curtimestamp.tv_sec - lasttstamp->tv_sec; |
universe@36 | 175 | suseconds_t micros; |
universe@40 | 176 | if (curtimestamp.tv_usec < lasttstamp->tv_usec) { |
universe@40 | 177 | micros = 1e6L-(lasttstamp->tv_usec - curtimestamp.tv_usec); |
universe@33 | 178 | sec--; |
universe@33 | 179 | } else { |
universe@40 | 180 | micros = curtimestamp.tv_usec - lasttstamp->tv_usec; |
universe@33 | 181 | } |
universe@33 | 182 | |
universe@33 | 183 | elem->move.movetime.tv_sec = sec; |
universe@36 | 184 | elem->move.movetime.tv_usec = micros; |
universe@33 | 185 | |
universe@23 | 186 | gamestate->lastmove->next = elem; |
universe@23 | 187 | gamestate->lastmove = elem; |
universe@63 | 188 | gamestate->movecount++; |
universe@23 | 189 | } else { |
universe@36 | 190 | elem->move.movetime.tv_usec = 0; |
universe@33 | 191 | elem->move.movetime.tv_sec = 0; |
universe@23 | 192 | gamestate->movelist = gamestate->lastmove = elem; |
universe@63 | 193 | gamestate->movecount = 1; |
universe@23 | 194 | } |
universe@23 | 195 | } |
universe@19 | 196 | |
universe@19 | 197 | char getpiecechr(uint8_t piece) { |
universe@19 | 198 | switch (piece & PIECE_MASK) { |
universe@19 | 199 | case ROOK: return 'R'; |
universe@19 | 200 | case KNIGHT: return 'N'; |
universe@19 | 201 | case BISHOP: return 'B'; |
universe@19 | 202 | case QUEEN: return 'Q'; |
universe@19 | 203 | case KING: return 'K'; |
universe@19 | 204 | default: return '\0'; |
universe@19 | 205 | } |
universe@19 | 206 | } |
universe@19 | 207 | |
universe@19 | 208 | uint8_t getpiece(char c) { |
universe@19 | 209 | switch (c) { |
universe@19 | 210 | case 'R': return ROOK; |
universe@19 | 211 | case 'N': return KNIGHT; |
universe@19 | 212 | case 'B': return BISHOP; |
universe@19 | 213 | case 'Q': return QUEEN; |
universe@19 | 214 | case 'K': return KING; |
universe@19 | 215 | default: return 0; |
universe@19 | 216 | } |
universe@19 | 217 | } |
universe@19 | 218 | |
universe@49 | 219 | static void apply_move_impl(GameState *gamestate, Move *move, _Bool simulate) { |
universe@66 | 220 | /* format move before moving (s.t. ambiguities can be resolved) */ |
universe@66 | 221 | if (!simulate) { |
universe@66 | 222 | if (!move->string[0]) { |
universe@66 | 223 | format_move(gamestate, move); |
universe@66 | 224 | } |
universe@66 | 225 | } |
universe@66 | 226 | |
universe@19 | 227 | uint8_t piece = move->piece & PIECE_MASK; |
universe@19 | 228 | uint8_t color = move->piece & COLOR_MASK; |
universe@19 | 229 | |
universe@19 | 230 | /* en passant capture */ |
universe@19 | 231 | if (move->capture && piece == PAWN && |
universe@23 | 232 | mdst(gamestate->board, move) == 0) { |
universe@23 | 233 | gamestate->board[move->fromrow][move->tofile] = 0; |
universe@19 | 234 | } |
universe@19 | 235 | |
universe@19 | 236 | /* remove old en passant threats */ |
universe@19 | 237 | for (uint8_t file = 0 ; file < 8 ; file++) { |
universe@23 | 238 | gamestate->board[3][file] &= ~ENPASSANT_THREAT; |
universe@23 | 239 | gamestate->board[4][file] &= ~ENPASSANT_THREAT; |
universe@19 | 240 | } |
universe@19 | 241 | |
universe@19 | 242 | /* add new en passant threat */ |
universe@19 | 243 | if (piece == PAWN && ( |
universe@19 | 244 | (move->fromrow == 1 && move->torow == 3) || |
universe@19 | 245 | (move->fromrow == 6 && move->torow == 4))) { |
universe@19 | 246 | move->piece |= ENPASSANT_THREAT; |
universe@19 | 247 | } |
universe@19 | 248 | |
universe@19 | 249 | /* move (and maybe capture or promote) */ |
universe@23 | 250 | msrc(gamestate->board, move) = 0; |
universe@19 | 251 | if (move->promotion) { |
universe@23 | 252 | mdst(gamestate->board, move) = move->promotion; |
universe@19 | 253 | } else { |
universe@23 | 254 | mdst(gamestate->board, move) = move->piece; |
universe@19 | 255 | } |
universe@19 | 256 | |
universe@19 | 257 | /* castling */ |
universe@49 | 258 | if (piece == KING && move->fromfile == fileidx('e')) { |
universe@19 | 259 | if (move->tofile == fileidx('g')) { |
universe@23 | 260 | gamestate->board[move->torow][fileidx('h')] = 0; |
universe@23 | 261 | gamestate->board[move->torow][fileidx('f')] = color|ROOK; |
universe@19 | 262 | } else if (move->tofile == fileidx('c')) { |
universe@23 | 263 | gamestate->board[move->torow][fileidx('a')] = 0; |
universe@23 | 264 | gamestate->board[move->torow][fileidx('d')] = color|ROOK; |
universe@19 | 265 | } |
universe@19 | 266 | } |
universe@66 | 267 | |
universe@49 | 268 | /* add move, even in simulation (checkmate test needs it) */ |
universe@23 | 269 | addmove(gamestate, move); |
universe@19 | 270 | } |
universe@19 | 271 | |
universe@49 | 272 | void apply_move(GameState *gamestate, Move *move) { |
universe@49 | 273 | apply_move_impl(gamestate, move, 0); |
universe@49 | 274 | } |
universe@49 | 275 | |
universe@48 | 276 | static int validate_move_rules(GameState *gamestate, Move *move) { |
universe@19 | 277 | /* validate indices (don't trust opponent) */ |
universe@19 | 278 | if (!chkidx(move)) { |
universe@48 | 279 | return INVALID_POSITION; |
universe@19 | 280 | } |
universe@19 | 281 | |
universe@21 | 282 | /* must move */ |
universe@21 | 283 | if (move->fromfile == move->tofile && move->fromrow == move->torow) { |
universe@48 | 284 | return INVALID_MOVE_SYNTAX; |
universe@21 | 285 | } |
universe@21 | 286 | |
universe@19 | 287 | /* does piece exist */ |
universe@47 | 288 | if ((msrc(gamestate->board, move)&(PIECE_MASK|COLOR_MASK)) |
universe@47 | 289 | != (move->piece&(PIECE_MASK|COLOR_MASK))) { |
universe@48 | 290 | return INVALID_POSITION; |
universe@29 | 291 | } |
universe@19 | 292 | |
universe@19 | 293 | /* can't capture own pieces */ |
universe@29 | 294 | if ((mdst(gamestate->board, move) & COLOR_MASK) |
universe@47 | 295 | == (move->piece & COLOR_MASK)) { |
universe@48 | 296 | return RULES_VIOLATED; |
universe@47 | 297 | } |
universe@47 | 298 | |
universe@47 | 299 | /* must capture, if and only if destination is occupied */ |
universe@47 | 300 | if ((mdst(gamestate->board, move) == 0 && move->capture) || |
universe@47 | 301 | (mdst(gamestate->board, move) != 0 && !move->capture)) { |
universe@48 | 302 | return INVALID_MOVE_SYNTAX; |
universe@19 | 303 | } |
universe@19 | 304 | |
universe@19 | 305 | /* validate individual rules */ |
universe@48 | 306 | _Bool chkrules; |
universe@19 | 307 | switch (move->piece & PIECE_MASK) { |
universe@19 | 308 | case PAWN: |
universe@48 | 309 | chkrules = pawn_chkrules(gamestate, move) && |
universe@29 | 310 | !pawn_isblocked(gamestate, move); |
universe@48 | 311 | break; |
universe@19 | 312 | case ROOK: |
universe@48 | 313 | chkrules = rook_chkrules(move) && |
universe@29 | 314 | !rook_isblocked(gamestate, move); |
universe@48 | 315 | break; |
universe@19 | 316 | case KNIGHT: |
universe@48 | 317 | chkrules = knight_chkrules(move); /* knight is never blocked */ |
universe@48 | 318 | break; |
universe@19 | 319 | case BISHOP: |
universe@48 | 320 | chkrules = bishop_chkrules(move) && |
universe@29 | 321 | !bishop_isblocked(gamestate, move); |
universe@48 | 322 | break; |
universe@19 | 323 | case QUEEN: |
universe@48 | 324 | chkrules = queen_chkrules(move) && |
universe@29 | 325 | !queen_isblocked(gamestate, move); |
universe@48 | 326 | break; |
universe@19 | 327 | case KING: |
universe@48 | 328 | chkrules = king_chkrules(gamestate, move) && |
universe@29 | 329 | !king_isblocked(gamestate, move); |
universe@48 | 330 | break; |
universe@19 | 331 | default: |
universe@48 | 332 | return INVALID_MOVE_SYNTAX; |
universe@19 | 333 | } |
universe@48 | 334 | |
universe@48 | 335 | return chkrules ? VALID_MOVE_SEMANTICS : RULES_VIOLATED; |
universe@29 | 336 | } |
universe@29 | 337 | |
universe@48 | 338 | int validate_move(GameState *gamestate, Move *move) { |
universe@19 | 339 | |
universe@48 | 340 | int result = validate_move_rules(gamestate, move); |
universe@29 | 341 | |
universe@29 | 342 | /* cancel processing to save resources */ |
universe@48 | 343 | if (result != VALID_MOVE_SEMANTICS) { |
universe@48 | 344 | return result; |
universe@25 | 345 | } |
universe@25 | 346 | |
universe@62 | 347 | /* simulate move for check validation */ |
universe@62 | 348 | GameState simulation = gamestate_copy_sim(gamestate); |
universe@62 | 349 | Move simmove = *move; |
universe@62 | 350 | apply_move_impl(&simulation, &simmove, 1); |
universe@62 | 351 | |
universe@28 | 352 | /* find kings for check validation */ |
universe@29 | 353 | uint8_t piececolor = (move->piece & COLOR_MASK); |
universe@29 | 354 | |
universe@28 | 355 | uint8_t mykingfile = 0, mykingrow = 0, opkingfile = 0, opkingrow = 0; |
universe@28 | 356 | for (uint8_t row = 0 ; row < 8 ; row++) { |
universe@28 | 357 | for (uint8_t file = 0 ; file < 8 ; file++) { |
universe@62 | 358 | if (simulation.board[row][file] == |
universe@28 | 359 | (piececolor == WHITE?WKING:BKING)) { |
universe@28 | 360 | mykingfile = file; |
universe@28 | 361 | mykingrow = row; |
universe@62 | 362 | } else if (simulation.board[row][file] == |
universe@28 | 363 | (piececolor == WHITE?BKING:WKING)) { |
universe@28 | 364 | opkingfile = file; |
universe@28 | 365 | opkingrow = row; |
universe@28 | 366 | } |
universe@28 | 367 | } |
universe@28 | 368 | } |
universe@28 | 369 | |
universe@28 | 370 | /* don't move into or stay in check position */ |
universe@28 | 371 | if (is_covered(&simulation, mykingrow, mykingfile, |
universe@28 | 372 | opponent_color(piececolor))) { |
universe@48 | 373 | |
universe@48 | 374 | gamestate_cleanup(&simulation); |
universe@48 | 375 | if ((move->piece & PIECE_MASK) == KING) { |
universe@48 | 376 | return KING_MOVES_INTO_CHECK; |
universe@48 | 377 | } else { |
universe@48 | 378 | /* last move is always not null in this case */ |
universe@48 | 379 | return gamestate->lastmove->move.check ? |
universe@48 | 380 | KING_IN_CHECK : PIECE_PINNED; |
universe@48 | 381 | } |
universe@28 | 382 | } |
universe@19 | 383 | |
universe@25 | 384 | /* correct check and checkmate flags (move is still valid) */ |
universe@29 | 385 | Move threats[16]; |
universe@29 | 386 | uint8_t threatcount; |
universe@29 | 387 | move->check = get_threats(&simulation, opkingrow, opkingfile, |
universe@29 | 388 | piececolor, threats, &threatcount); |
universe@19 | 389 | |
universe@28 | 390 | if (move->check) { |
universe@28 | 391 | /* determine possible escape fields */ |
universe@28 | 392 | _Bool canescape = 0; |
universe@28 | 393 | for (int dr = -1 ; dr <= 1 && !canescape ; dr++) { |
universe@28 | 394 | for (int df = -1 ; df <= 1 && !canescape ; df++) { |
universe@28 | 395 | if (!(dr == 0 && df == 0) && |
universe@28 | 396 | isidx(opkingrow + dr) && isidx(opkingfile + df)) { |
universe@28 | 397 | |
universe@28 | 398 | /* escape field neither blocked nor covered */ |
universe@28 | 399 | if ((simulation.board[opkingrow + dr][opkingfile + df] |
universe@28 | 400 | & COLOR_MASK) != opponent_color(piececolor)) { |
universe@28 | 401 | canescape |= !is_covered(&simulation, |
universe@28 | 402 | opkingrow + dr, opkingfile + df, piececolor); |
universe@28 | 403 | } |
universe@28 | 404 | } |
universe@28 | 405 | } |
universe@28 | 406 | } |
universe@29 | 407 | /* can't escape, can he capture? */ |
universe@29 | 408 | if (!canescape && threatcount == 1) { |
universe@29 | 409 | canescape = is_attacked(&simulation, threats[0].fromrow, |
universe@29 | 410 | threats[0].fromfile, opponent_color(piececolor)); |
universe@29 | 411 | } |
universe@29 | 412 | |
universe@29 | 413 | /* can't capture, can he block? */ |
universe@29 | 414 | if (!canescape && threatcount == 1) { |
universe@29 | 415 | Move *threat = &(threats[0]); |
universe@29 | 416 | uint8_t threatpiece = threat->piece & PIECE_MASK; |
universe@29 | 417 | |
universe@29 | 418 | /* knight, pawns and the king cannot be blocked */ |
universe@29 | 419 | if (threatpiece == BISHOP || threatpiece == ROOK |
universe@29 | 420 | || threatpiece == QUEEN) { |
universe@29 | 421 | if (threat->fromrow == threat->torow) { |
universe@29 | 422 | /* rook aspect (on row) */ |
universe@29 | 423 | int d = threat->tofile > threat->fromfile ? 1 : -1; |
universe@29 | 424 | uint8_t file = threat->fromfile; |
universe@29 | 425 | while (!canescape && file != threat->tofile - d) { |
universe@29 | 426 | file += d; |
universe@29 | 427 | canescape |= is_protected(&simulation, |
universe@29 | 428 | threat->torow, file, opponent_color(piececolor)); |
universe@29 | 429 | } |
universe@29 | 430 | } else if (threat->fromfile == threat->tofile) { |
universe@29 | 431 | /* rook aspect (on file) */ |
universe@29 | 432 | int d = threat->torow > threat->fromrow ? 1 : -1; |
universe@29 | 433 | uint8_t row = threat->fromrow; |
universe@29 | 434 | while (!canescape && row != threat->torow - d) { |
universe@29 | 435 | row += d; |
universe@29 | 436 | canescape |= is_protected(&simulation, |
universe@29 | 437 | row, threat->tofile, opponent_color(piececolor)); |
universe@29 | 438 | } |
universe@29 | 439 | } else { |
universe@29 | 440 | /* bishop aspect */ |
universe@51 | 441 | int dr = threat->torow > threat->fromrow ? 1 : -1; |
universe@51 | 442 | int df = threat->tofile > threat->fromfile ? 1 : -1; |
universe@29 | 443 | |
universe@51 | 444 | uint8_t row = threat->fromrow; |
universe@51 | 445 | uint8_t file = threat->fromfile; |
universe@51 | 446 | while (!canescape && file != threat->tofile - df |
universe@51 | 447 | && row != threat->torow - dr) { |
universe@29 | 448 | row += dr; |
universe@29 | 449 | file += df; |
universe@29 | 450 | canescape |= is_protected(&simulation, row, file, |
universe@29 | 451 | opponent_color(piececolor)); |
universe@29 | 452 | } |
universe@29 | 453 | } |
universe@29 | 454 | } |
universe@29 | 455 | } |
universe@29 | 456 | |
universe@28 | 457 | if (!canescape) { |
universe@29 | 458 | gamestate->checkmate = 1; |
universe@28 | 459 | } |
universe@28 | 460 | } |
universe@28 | 461 | |
universe@48 | 462 | gamestate_cleanup(&simulation); |
universe@48 | 463 | |
universe@48 | 464 | return VALID_MOVE_SEMANTICS; |
universe@19 | 465 | } |
universe@19 | 466 | |
universe@47 | 467 | _Bool get_threats(GameState *gamestate, uint8_t row, uint8_t file, |
universe@47 | 468 | uint8_t color, Move *threats, uint8_t *threatcount) { |
universe@47 | 469 | Move candidates[32]; |
universe@47 | 470 | int candidatecount = 0; |
universe@47 | 471 | for (uint8_t r = 0 ; r < 8 ; r++) { |
universe@47 | 472 | for (uint8_t f = 0 ; f < 8 ; f++) { |
universe@47 | 473 | if ((gamestate->board[r][f] & COLOR_MASK) == color) { |
universe@64 | 474 | /* non-capturing move */ |
universe@47 | 475 | memset(&(candidates[candidatecount]), 0, sizeof(Move)); |
universe@47 | 476 | candidates[candidatecount].piece = gamestate->board[r][f]; |
universe@47 | 477 | candidates[candidatecount].fromrow = r; |
universe@47 | 478 | candidates[candidatecount].fromfile = f; |
universe@47 | 479 | candidates[candidatecount].torow = row; |
universe@47 | 480 | candidates[candidatecount].tofile = file; |
universe@47 | 481 | candidatecount++; |
universe@47 | 482 | |
universe@64 | 483 | /* capturing move */ |
universe@47 | 484 | memcpy(&(candidates[candidatecount]), |
universe@47 | 485 | &(candidates[candidatecount-1]), sizeof(Move)); |
universe@47 | 486 | candidates[candidatecount].capture = 1; |
universe@47 | 487 | candidatecount++; |
universe@47 | 488 | } |
universe@47 | 489 | } |
universe@47 | 490 | } |
universe@47 | 491 | |
universe@47 | 492 | if (threatcount) { |
universe@47 | 493 | *threatcount = 0; |
universe@47 | 494 | } |
universe@47 | 495 | |
universe@47 | 496 | |
universe@47 | 497 | _Bool result = 0; |
universe@47 | 498 | |
universe@47 | 499 | for (int i = 0 ; i < candidatecount ; i++) { |
universe@48 | 500 | if (validate_move_rules(gamestate, &(candidates[i])) |
universe@48 | 501 | == VALID_MOVE_SEMANTICS) { |
universe@47 | 502 | result = 1; |
universe@47 | 503 | if (threats && threatcount) { |
universe@47 | 504 | threats[(*threatcount)++] = candidates[i]; |
universe@47 | 505 | } |
universe@47 | 506 | } |
universe@47 | 507 | } |
universe@47 | 508 | |
universe@47 | 509 | return result; |
universe@47 | 510 | } |
universe@47 | 511 | |
universe@47 | 512 | _Bool is_pinned(GameState *gamestate, Move *move) { |
universe@47 | 513 | uint8_t color = move->piece & COLOR_MASK; |
universe@47 | 514 | |
universe@62 | 515 | GameState simulation = gamestate_copy_sim(gamestate); |
universe@62 | 516 | Move simmove = *move; |
universe@62 | 517 | apply_move(&simulation, &simmove); |
universe@62 | 518 | |
universe@47 | 519 | uint8_t kingfile = 0, kingrow = 0; |
universe@47 | 520 | for (uint8_t row = 0 ; row < 8 ; row++) { |
universe@47 | 521 | for (uint8_t file = 0 ; file < 8 ; file++) { |
universe@62 | 522 | if (simulation.board[row][file] == (color|KING)) { |
universe@47 | 523 | kingfile = file; |
universe@47 | 524 | kingrow = row; |
universe@47 | 525 | } |
universe@47 | 526 | } |
universe@47 | 527 | } |
universe@62 | 528 | |
universe@48 | 529 | _Bool covered = is_covered(&simulation, |
universe@48 | 530 | kingrow, kingfile, opponent_color(color)); |
universe@48 | 531 | gamestate_cleanup(&simulation); |
universe@48 | 532 | |
universe@48 | 533 | return covered; |
universe@47 | 534 | } |
universe@47 | 535 | |
universe@47 | 536 | _Bool get_real_threats(GameState *gamestate, uint8_t row, uint8_t file, |
universe@47 | 537 | uint8_t color, Move *threats, uint8_t *threatcount) { |
universe@47 | 538 | |
universe@47 | 539 | if (threatcount) { |
universe@47 | 540 | *threatcount = 0; |
universe@47 | 541 | } |
universe@47 | 542 | |
universe@47 | 543 | Move candidates[16]; |
universe@47 | 544 | uint8_t candidatecount; |
universe@47 | 545 | if (get_threats(gamestate, row, file, color, candidates, &candidatecount)) { |
universe@47 | 546 | |
universe@47 | 547 | _Bool result = 0; |
universe@47 | 548 | uint8_t kingfile = 0, kingrow = 0; |
universe@47 | 549 | for (uint8_t row = 0 ; row < 8 ; row++) { |
universe@47 | 550 | for (uint8_t file = 0 ; file < 8 ; file++) { |
universe@47 | 551 | if (gamestate->board[row][file] == (color|KING)) { |
universe@47 | 552 | kingfile = file; |
universe@47 | 553 | kingrow = row; |
universe@47 | 554 | } |
universe@47 | 555 | } |
universe@47 | 556 | } |
universe@47 | 557 | |
universe@47 | 558 | for (uint8_t i = 0 ; i < candidatecount ; i++) { |
universe@48 | 559 | GameState simulation = gamestate_copy_sim(gamestate); |
universe@47 | 560 | Move simmove = candidates[i]; |
universe@47 | 561 | apply_move(&simulation, &simmove); |
universe@47 | 562 | if (!is_covered(&simulation, kingrow, kingfile, |
universe@47 | 563 | opponent_color(color))) { |
universe@47 | 564 | result = 1; |
universe@47 | 565 | if (threats && threatcount) { |
universe@47 | 566 | threats[(*threatcount)++] = candidates[i]; |
universe@47 | 567 | } |
universe@47 | 568 | } |
universe@47 | 569 | } |
universe@47 | 570 | |
universe@47 | 571 | return result; |
universe@47 | 572 | } else { |
universe@47 | 573 | return 0; |
universe@47 | 574 | } |
universe@47 | 575 | } |
universe@48 | 576 | |
universe@47 | 577 | static int getlocation(GameState *gamestate, Move *move) { |
universe@47 | 578 | |
universe@47 | 579 | uint8_t color = move->piece & COLOR_MASK; |
universe@47 | 580 | _Bool incheck = gamestate->lastmove?gamestate->lastmove->move.check:0; |
universe@47 | 581 | |
universe@47 | 582 | Move threats[16], *threat = NULL; |
universe@47 | 583 | uint8_t threatcount; |
universe@47 | 584 | |
universe@47 | 585 | if (get_threats(gamestate, move->torow, move->tofile, color, |
universe@47 | 586 | threats, &threatcount)) { |
universe@47 | 587 | |
universe@49 | 588 | int reason = INVALID_POSITION; |
universe@49 | 589 | |
universe@64 | 590 | /* find threats for the specified position */ |
universe@62 | 591 | for (uint8_t i = 0 ; i < threatcount ; i++) { |
universe@47 | 592 | if ((threats[i].piece & (PIECE_MASK | COLOR_MASK)) |
universe@47 | 593 | == move->piece && |
universe@47 | 594 | (move->fromrow == POS_UNSPECIFIED || |
universe@47 | 595 | move->fromrow == threats[i].fromrow) && |
universe@47 | 596 | (move->fromfile == POS_UNSPECIFIED || |
universe@47 | 597 | move->fromfile == threats[i].fromfile)) { |
universe@47 | 598 | |
universe@47 | 599 | if (threat) { |
universe@47 | 600 | return AMBIGUOUS_MOVE; |
universe@47 | 601 | } else { |
universe@64 | 602 | /* found threat is no real threat */ |
universe@49 | 603 | if (is_pinned(gamestate, &(threats[i]))) { |
universe@49 | 604 | reason = incheck?KING_IN_CHECK:PIECE_PINNED; |
universe@49 | 605 | } else { |
universe@49 | 606 | threat = &(threats[i]); |
universe@49 | 607 | } |
universe@47 | 608 | } |
universe@47 | 609 | } |
universe@47 | 610 | } |
universe@47 | 611 | |
universe@64 | 612 | /* can't threaten specified position */ |
universe@47 | 613 | if (!threat) { |
universe@49 | 614 | return reason; |
universe@47 | 615 | } |
universe@47 | 616 | |
universe@49 | 617 | memcpy(move, threat, sizeof(Move)); |
universe@49 | 618 | return VALID_MOVE_SYNTAX; |
universe@47 | 619 | } else { |
universe@47 | 620 | return INVALID_POSITION; |
universe@47 | 621 | } |
universe@47 | 622 | } |
universe@47 | 623 | |
universe@50 | 624 | int eval_move(GameState *gamestate, char *mstr, Move *move, uint8_t color) { |
universe@19 | 625 | memset(move, 0, sizeof(Move)); |
universe@19 | 626 | move->fromfile = POS_UNSPECIFIED; |
universe@19 | 627 | move->fromrow = POS_UNSPECIFIED; |
universe@19 | 628 | |
universe@19 | 629 | size_t len = strlen(mstr); |
universe@48 | 630 | if (len < 1 || len > 6) { |
universe@48 | 631 | return INVALID_MOVE_SYNTAX; |
universe@48 | 632 | } |
universe@19 | 633 | |
universe@19 | 634 | /* evaluate check/checkmate flags */ |
universe@19 | 635 | if (mstr[len-1] == '+') { |
universe@19 | 636 | len--; mstr[len] = '\0'; |
universe@19 | 637 | move->check = 1; |
universe@19 | 638 | } else if (mstr[len-1] == '#') { |
universe@19 | 639 | len--; mstr[len] = '\0'; |
universe@27 | 640 | /* ignore - validation should set game state */ |
universe@19 | 641 | } |
universe@19 | 642 | |
universe@19 | 643 | /* evaluate promotion */ |
universe@19 | 644 | if (len > 3 && mstr[len-2] == '=') { |
universe@19 | 645 | move->promotion = getpiece(mstr[len-1]); |
universe@19 | 646 | if (!move->promotion) { |
universe@19 | 647 | return INVALID_MOVE_SYNTAX; |
universe@19 | 648 | } else { |
universe@50 | 649 | move->promotion |= color; |
universe@19 | 650 | len -= 2; |
universe@19 | 651 | mstr[len] = 0; |
universe@19 | 652 | } |
universe@19 | 653 | } |
universe@19 | 654 | |
universe@19 | 655 | if (len == 2) { |
universe@19 | 656 | /* pawn move (e.g. "e4") */ |
universe@19 | 657 | move->piece = PAWN; |
universe@19 | 658 | move->tofile = fileidx(mstr[0]); |
universe@19 | 659 | move->torow = rowidx(mstr[1]); |
universe@19 | 660 | } else if (len == 3) { |
universe@19 | 661 | if (strcmp(mstr, "O-O") == 0) { |
universe@19 | 662 | /* king side castling */ |
universe@19 | 663 | move->piece = KING; |
universe@19 | 664 | move->fromfile = fileidx('e'); |
universe@19 | 665 | move->tofile = fileidx('g'); |
universe@50 | 666 | move->fromrow = move->torow = color == WHITE ? 0 : 7; |
universe@19 | 667 | } else { |
universe@19 | 668 | /* move (e.g. "Nf3") */ |
universe@19 | 669 | move->piece = getpiece(mstr[0]); |
universe@19 | 670 | move->tofile = fileidx(mstr[1]); |
universe@19 | 671 | move->torow = rowidx(mstr[2]); |
universe@19 | 672 | } |
universe@19 | 673 | } else if (len == 4) { |
universe@19 | 674 | move->piece = getpiece(mstr[0]); |
universe@19 | 675 | if (!move->piece) { |
universe@19 | 676 | move->piece = PAWN; |
universe@19 | 677 | move->fromfile = fileidx(mstr[0]); |
universe@19 | 678 | } |
universe@19 | 679 | if (mstr[1] == 'x') { |
universe@19 | 680 | /* capture (e.g. "Nxf3", "dxe5") */ |
universe@19 | 681 | move->capture = 1; |
universe@19 | 682 | } else { |
universe@19 | 683 | /* move (e.g. "Ndf3", "N2c3", "e2e4") */ |
universe@19 | 684 | if (isfile(mstr[1])) { |
universe@19 | 685 | move->fromfile = fileidx(mstr[1]); |
universe@19 | 686 | if (move->piece == PAWN) { |
universe@19 | 687 | move->piece = 0; |
universe@19 | 688 | } |
universe@19 | 689 | } else { |
universe@19 | 690 | move->fromrow = rowidx(mstr[1]); |
universe@19 | 691 | } |
universe@19 | 692 | } |
universe@19 | 693 | move->tofile = fileidx(mstr[2]); |
universe@19 | 694 | move->torow = rowidx(mstr[3]); |
universe@19 | 695 | } else if (len == 5) { |
universe@19 | 696 | if (strcmp(mstr, "O-O-O") == 0) { |
universe@19 | 697 | /* queen side castling "O-O-O" */ |
universe@19 | 698 | move->piece = KING; |
universe@19 | 699 | move->fromfile = fileidx('e'); |
universe@19 | 700 | move->tofile = fileidx('c'); |
universe@50 | 701 | move->fromrow = move->torow = color == WHITE ? 0 : 7; |
universe@19 | 702 | } else { |
universe@19 | 703 | move->piece = getpiece(mstr[0]); |
universe@19 | 704 | if (mstr[2] == 'x') { |
universe@19 | 705 | move->capture = 1; |
universe@19 | 706 | if (move->piece) { |
universe@19 | 707 | /* capture (e.g. "Ndxf3") */ |
universe@19 | 708 | move->fromfile = fileidx(mstr[1]); |
universe@19 | 709 | } else { |
universe@19 | 710 | /* long notation capture (e.g. "e5xf6") */ |
universe@19 | 711 | move->piece = PAWN; |
universe@19 | 712 | move->fromfile = fileidx(mstr[0]); |
universe@19 | 713 | move->fromrow = rowidx(mstr[1]); |
universe@19 | 714 | } |
universe@19 | 715 | } else { |
universe@19 | 716 | /* long notation move (e.g. "Nc5a4") */ |
universe@19 | 717 | move->fromfile = fileidx(mstr[1]); |
universe@19 | 718 | move->fromrow = rowidx(mstr[2]); |
universe@19 | 719 | } |
universe@19 | 720 | move->tofile = fileidx(mstr[3]); |
universe@19 | 721 | move->torow = rowidx(mstr[4]); |
universe@19 | 722 | } |
universe@19 | 723 | } else if (len == 6) { |
universe@19 | 724 | /* long notation capture (e.g. "Nc5xf3") */ |
universe@19 | 725 | if (mstr[3] == 'x') { |
universe@19 | 726 | move->capture = 1; |
universe@19 | 727 | move->piece = getpiece(mstr[0]); |
universe@19 | 728 | move->fromfile = fileidx(mstr[1]); |
universe@19 | 729 | move->fromrow = rowidx(mstr[2]); |
universe@19 | 730 | move->tofile = fileidx(mstr[4]); |
universe@19 | 731 | move->torow = rowidx(mstr[5]); |
universe@19 | 732 | } |
universe@19 | 733 | } |
universe@19 | 734 | |
universe@19 | 735 | |
universe@19 | 736 | if (move->piece) { |
universe@23 | 737 | if (move->piece == PAWN |
universe@50 | 738 | && move->torow == (color==WHITE?7:0) |
universe@19 | 739 | && !move->promotion) { |
universe@19 | 740 | return NEED_PROMOTION; |
universe@19 | 741 | } |
universe@19 | 742 | |
universe@50 | 743 | move->piece |= color; |
universe@19 | 744 | if (move->fromfile == POS_UNSPECIFIED |
universe@19 | 745 | || move->fromrow == POS_UNSPECIFIED) { |
universe@23 | 746 | return getlocation(gamestate, move); |
universe@19 | 747 | } else { |
universe@19 | 748 | return chkidx(move) ? VALID_MOVE_SYNTAX : INVALID_POSITION; |
universe@19 | 749 | } |
universe@19 | 750 | } else { |
universe@19 | 751 | return INVALID_MOVE_SYNTAX; |
universe@19 | 752 | } |
universe@19 | 753 | } |
universe@29 | 754 | |
universe@29 | 755 | _Bool is_protected(GameState *gamestate, uint8_t row, uint8_t file, |
universe@29 | 756 | uint8_t color) { |
universe@29 | 757 | |
universe@29 | 758 | Move threats[16]; |
universe@29 | 759 | uint8_t threatcount; |
universe@29 | 760 | if (get_real_threats(gamestate, row, file, color, threats, &threatcount)) { |
universe@29 | 761 | for (int i = 0 ; i < threatcount ; i++) { |
universe@29 | 762 | if (threats[i].piece != (color|KING)) { |
universe@29 | 763 | return 1; |
universe@29 | 764 | } |
universe@29 | 765 | } |
universe@29 | 766 | return 0; |
universe@29 | 767 | } else { |
universe@29 | 768 | return 0; |
universe@29 | 769 | } |
universe@29 | 770 | } |
universe@33 | 771 | |
universe@33 | 772 | uint16_t remaining_movetime(GameInfo *gameinfo, GameState *gamestate, |
universe@33 | 773 | uint8_t color) { |
universe@33 | 774 | if (!gameinfo->timecontrol) { |
universe@33 | 775 | return 0; |
universe@33 | 776 | } |
universe@33 | 777 | |
universe@33 | 778 | if (gamestate->movelist) { |
universe@33 | 779 | uint16_t time = gameinfo->time; |
universe@36 | 780 | suseconds_t micros = 0; |
universe@33 | 781 | |
universe@33 | 782 | MoveList *movelist = color == WHITE ? |
universe@33 | 783 | gamestate->movelist : gamestate->movelist->next; |
universe@33 | 784 | |
universe@33 | 785 | while (movelist) { |
universe@33 | 786 | time += gameinfo->addtime; |
universe@33 | 787 | |
universe@40 | 788 | struct movetimeval *movetime = &(movelist->move.movetime); |
universe@33 | 789 | if (movetime->tv_sec >= time) { |
universe@33 | 790 | return 0; |
universe@33 | 791 | } |
universe@33 | 792 | |
universe@33 | 793 | time -= movetime->tv_sec; |
universe@36 | 794 | micros += movetime->tv_usec; |
universe@33 | 795 | |
universe@33 | 796 | movelist = movelist->next ? movelist->next->next : NULL; |
universe@33 | 797 | } |
universe@33 | 798 | |
universe@33 | 799 | time_t sec; |
universe@33 | 800 | movelist = gamestate->lastmove; |
universe@33 | 801 | if ((movelist->move.piece & COLOR_MASK) != color) { |
universe@40 | 802 | struct movetimeval *lastmovetstamp = &(movelist->move.timestamp); |
universe@36 | 803 | struct timeval currenttstamp; |
universe@36 | 804 | gettimeofday(¤ttstamp, NULL); |
universe@36 | 805 | micros += currenttstamp.tv_usec - lastmovetstamp->tv_usec; |
universe@33 | 806 | sec = currenttstamp.tv_sec - lastmovetstamp->tv_sec; |
universe@33 | 807 | if (sec >= time) { |
universe@33 | 808 | return 0; |
universe@33 | 809 | } |
universe@33 | 810 | |
universe@33 | 811 | time -= sec; |
universe@33 | 812 | } |
universe@33 | 813 | |
universe@36 | 814 | sec = micros / 1e6L; |
universe@33 | 815 | |
universe@33 | 816 | if (sec >= time) { |
universe@33 | 817 | return 0; |
universe@33 | 818 | } |
universe@33 | 819 | |
universe@33 | 820 | time -= sec; |
universe@33 | 821 | |
universe@33 | 822 | return time; |
universe@33 | 823 | } else { |
universe@33 | 824 | return gameinfo->time; |
universe@33 | 825 | } |
universe@33 | 826 | } |