Mon, 31 Mar 2014 11:16:32 +0200
moved chess rules to separate lib
universe@19 | 1 | /* |
universe@19 | 2 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER. |
universe@19 | 3 | * |
universe@19 | 4 | * Copyright 2014 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@19 | 33 | |
universe@19 | 34 | char getpiecechr(uint8_t piece) { |
universe@19 | 35 | switch (piece & PIECE_MASK) { |
universe@19 | 36 | case ROOK: return 'R'; |
universe@19 | 37 | case KNIGHT: return 'N'; |
universe@19 | 38 | case BISHOP: return 'B'; |
universe@19 | 39 | case QUEEN: return 'Q'; |
universe@19 | 40 | case KING: return 'K'; |
universe@19 | 41 | default: return '\0'; |
universe@19 | 42 | } |
universe@19 | 43 | } |
universe@19 | 44 | |
universe@19 | 45 | uint8_t getpiece(char c) { |
universe@19 | 46 | switch (c) { |
universe@19 | 47 | case 'R': return ROOK; |
universe@19 | 48 | case 'N': return KNIGHT; |
universe@19 | 49 | case 'B': return BISHOP; |
universe@19 | 50 | case 'Q': return QUEEN; |
universe@19 | 51 | case 'K': return KING; |
universe@19 | 52 | default: return 0; |
universe@19 | 53 | } |
universe@19 | 54 | } |
universe@19 | 55 | |
universe@19 | 56 | /** |
universe@19 | 57 | * Guesses the location of a piece for short algebraic notation. |
universe@19 | 58 | * |
universe@19 | 59 | * @param board the current state of the board |
universe@19 | 60 | * @param move the move date to operate on |
universe@19 | 61 | * @return status code (see rules/rules.h for the codes) |
universe@19 | 62 | */ |
universe@19 | 63 | static int getlocation(Board board, Move *move) { |
universe@19 | 64 | uint8_t piece = move->piece & PIECE_MASK; |
universe@19 | 65 | switch (piece) { |
universe@19 | 66 | case PAWN: return pawn_getlocation(board, move); |
universe@19 | 67 | case ROOK: return rook_getlocation(board, move); |
universe@19 | 68 | case KNIGHT: return knight_getlocation(board, move); |
universe@19 | 69 | case BISHOP: return bishop_getlocation(board, move); |
universe@19 | 70 | case QUEEN: return queen_getlocation(board, move); |
universe@19 | 71 | case KING: return king_getlocation(board, move); |
universe@19 | 72 | default: return INVALID_MOVE_SYNTAX; |
universe@19 | 73 | } |
universe@19 | 74 | } |
universe@19 | 75 | |
universe@19 | 76 | |
universe@19 | 77 | void apply_move(Board board, Move *move) { |
universe@19 | 78 | uint8_t piece = move->piece & PIECE_MASK; |
universe@19 | 79 | uint8_t color = move->piece & COLOR_MASK; |
universe@19 | 80 | |
universe@19 | 81 | /* en passant capture */ |
universe@19 | 82 | if (move->capture && piece == PAWN && |
universe@19 | 83 | mdst(board, move) == 0) { |
universe@19 | 84 | board[move->fromrow][move->tofile] = 0; |
universe@19 | 85 | } |
universe@19 | 86 | |
universe@19 | 87 | /* remove old en passant threats */ |
universe@19 | 88 | for (uint8_t file = 0 ; file < 8 ; file++) { |
universe@19 | 89 | board[3][file] &= ~ENPASSANT_THREAT; |
universe@19 | 90 | board[4][file] &= ~ENPASSANT_THREAT; |
universe@19 | 91 | } |
universe@19 | 92 | |
universe@19 | 93 | /* add new en passant threat */ |
universe@19 | 94 | if (piece == PAWN && ( |
universe@19 | 95 | (move->fromrow == 1 && move->torow == 3) || |
universe@19 | 96 | (move->fromrow == 6 && move->torow == 4))) { |
universe@19 | 97 | move->piece |= ENPASSANT_THREAT; |
universe@19 | 98 | } |
universe@19 | 99 | |
universe@19 | 100 | /* move (and maybe capture or promote) */ |
universe@19 | 101 | msrc(board, move) = 0; |
universe@19 | 102 | if (move->promotion) { |
universe@19 | 103 | mdst(board, move) = move->promotion; |
universe@19 | 104 | } else { |
universe@19 | 105 | mdst(board, move) = move->piece; |
universe@19 | 106 | } |
universe@19 | 107 | |
universe@19 | 108 | /* castling */ |
universe@19 | 109 | if (piece == KING && |
universe@19 | 110 | move->fromfile == fileidx('e')) { |
universe@19 | 111 | |
universe@19 | 112 | if (move->tofile == fileidx('g')) { |
universe@19 | 113 | board[move->torow][fileidx('h')] = 0; |
universe@19 | 114 | board[move->torow][fileidx('f')] = color|ROOK; |
universe@19 | 115 | } else if (move->tofile == fileidx('c')) { |
universe@19 | 116 | board[move->torow][fileidx('a')] = 0; |
universe@19 | 117 | board[move->torow][fileidx('d')] = color|ROOK; |
universe@19 | 118 | } |
universe@19 | 119 | } |
universe@19 | 120 | } |
universe@19 | 121 | |
universe@19 | 122 | _Bool validate_move(Board board, Move *move) { |
universe@19 | 123 | _Bool result; |
universe@19 | 124 | |
universe@19 | 125 | /* validate indices (don't trust opponent) */ |
universe@19 | 126 | if (!chkidx(move)) { |
universe@19 | 127 | return 0; |
universe@19 | 128 | } |
universe@19 | 129 | |
universe@19 | 130 | /* does piece exist */ |
universe@19 | 131 | result = msrc(board, move) == move->piece; |
universe@19 | 132 | |
universe@19 | 133 | /* can't capture own pieces */ |
universe@19 | 134 | if ((mdst(board, move) & COLOR_MASK) == (move->piece & COLOR_MASK)) { |
universe@19 | 135 | return 0; |
universe@19 | 136 | } |
universe@19 | 137 | |
universe@19 | 138 | /* validate individual rules */ |
universe@19 | 139 | switch (move->piece & PIECE_MASK) { |
universe@19 | 140 | case PAWN: |
universe@19 | 141 | result = result && pawn_chkrules(board, move); |
universe@19 | 142 | result = result && !pawn_isblocked(board, move); |
universe@19 | 143 | break; |
universe@19 | 144 | case ROOK: |
universe@19 | 145 | result = result && rook_chkrules(move); |
universe@19 | 146 | result = result && !rook_isblocked(board, move); |
universe@19 | 147 | break; |
universe@19 | 148 | case KNIGHT: |
universe@19 | 149 | result = result && knight_chkrules(move); |
universe@19 | 150 | result = result && !knight_isblocked(board, move); |
universe@19 | 151 | break; |
universe@19 | 152 | case BISHOP: |
universe@19 | 153 | result = result && bishop_chkrules(move); |
universe@19 | 154 | result = result && !bishop_isblocked(board, move); |
universe@19 | 155 | break; |
universe@19 | 156 | case QUEEN: |
universe@19 | 157 | result = result && queen_chkrules(move); |
universe@19 | 158 | result = result && !queen_isblocked(board, move); |
universe@19 | 159 | break; |
universe@19 | 160 | case KING: |
universe@19 | 161 | result = result && king_chkrules(board, move); |
universe@19 | 162 | result = result && !king_isblocked(board, move); |
universe@19 | 163 | break; |
universe@19 | 164 | default: |
universe@19 | 165 | result = 0; |
universe@19 | 166 | } |
universe@19 | 167 | |
universe@19 | 168 | /* is piece pinned */ |
universe@19 | 169 | // TODO: make it so |
universe@19 | 170 | |
universe@19 | 171 | /* correct check and checkmate flags */ |
universe@19 | 172 | // TODO: make it so |
universe@19 | 173 | |
universe@19 | 174 | return result; |
universe@19 | 175 | } |
universe@19 | 176 | |
universe@19 | 177 | int eval_move(Board board, uint8_t mycolor, char *mstr, Move *move) { |
universe@19 | 178 | memset(move, 0, sizeof(Move)); |
universe@19 | 179 | move->fromfile = POS_UNSPECIFIED; |
universe@19 | 180 | move->fromrow = POS_UNSPECIFIED; |
universe@19 | 181 | |
universe@19 | 182 | size_t len = strlen(mstr); |
universe@19 | 183 | |
universe@19 | 184 | /* evaluate check/checkmate flags */ |
universe@19 | 185 | if (mstr[len-1] == '+') { |
universe@19 | 186 | len--; mstr[len] = '\0'; |
universe@19 | 187 | move->check = 1; |
universe@19 | 188 | } else if (mstr[len-1] == '#') { |
universe@19 | 189 | len--; mstr[len] = '\0'; |
universe@19 | 190 | move->checkmate = 1; |
universe@19 | 191 | } |
universe@19 | 192 | |
universe@19 | 193 | /* evaluate promotion */ |
universe@19 | 194 | if (len > 3 && mstr[len-2] == '=') { |
universe@19 | 195 | move->promotion = getpiece(mstr[len-1]); |
universe@19 | 196 | if (!move->promotion) { |
universe@19 | 197 | return INVALID_MOVE_SYNTAX; |
universe@19 | 198 | } else { |
universe@19 | 199 | move->promotion |= mycolor; |
universe@19 | 200 | len -= 2; |
universe@19 | 201 | mstr[len] = 0; |
universe@19 | 202 | } |
universe@19 | 203 | } |
universe@19 | 204 | |
universe@19 | 205 | if (len == 2) { |
universe@19 | 206 | /* pawn move (e.g. "e4") */ |
universe@19 | 207 | move->piece = PAWN; |
universe@19 | 208 | move->tofile = fileidx(mstr[0]); |
universe@19 | 209 | move->torow = rowidx(mstr[1]); |
universe@19 | 210 | } else if (len == 3) { |
universe@19 | 211 | if (strcmp(mstr, "O-O") == 0) { |
universe@19 | 212 | /* king side castling */ |
universe@19 | 213 | move->piece = KING; |
universe@19 | 214 | move->fromfile = fileidx('e'); |
universe@19 | 215 | move->tofile = fileidx('g'); |
universe@19 | 216 | move->fromrow = move->torow = mycolor == WHITE ? 0 : 7; |
universe@19 | 217 | } else { |
universe@19 | 218 | /* move (e.g. "Nf3") */ |
universe@19 | 219 | move->piece = getpiece(mstr[0]); |
universe@19 | 220 | move->tofile = fileidx(mstr[1]); |
universe@19 | 221 | move->torow = rowidx(mstr[2]); |
universe@19 | 222 | } |
universe@19 | 223 | |
universe@19 | 224 | } else if (len == 4) { |
universe@19 | 225 | move->piece = getpiece(mstr[0]); |
universe@19 | 226 | if (!move->piece) { |
universe@19 | 227 | move->piece = PAWN; |
universe@19 | 228 | move->fromfile = fileidx(mstr[0]); |
universe@19 | 229 | } |
universe@19 | 230 | if (mstr[1] == 'x') { |
universe@19 | 231 | /* capture (e.g. "Nxf3", "dxe5") */ |
universe@19 | 232 | move->capture = 1; |
universe@19 | 233 | } else { |
universe@19 | 234 | /* move (e.g. "Ndf3", "N2c3", "e2e4") */ |
universe@19 | 235 | if (isfile(mstr[1])) { |
universe@19 | 236 | move->fromfile = fileidx(mstr[1]); |
universe@19 | 237 | if (move->piece == PAWN) { |
universe@19 | 238 | move->piece = 0; |
universe@19 | 239 | } |
universe@19 | 240 | } else { |
universe@19 | 241 | move->fromrow = rowidx(mstr[1]); |
universe@19 | 242 | } |
universe@19 | 243 | } |
universe@19 | 244 | move->tofile = fileidx(mstr[2]); |
universe@19 | 245 | move->torow = rowidx(mstr[3]); |
universe@19 | 246 | } else if (len == 5) { |
universe@19 | 247 | if (strcmp(mstr, "O-O-O") == 0) { |
universe@19 | 248 | /* queen side castling "O-O-O" */ |
universe@19 | 249 | move->piece = KING; |
universe@19 | 250 | move->fromfile = fileidx('e'); |
universe@19 | 251 | move->tofile = fileidx('c'); |
universe@19 | 252 | move->fromrow = move->torow = mycolor == WHITE ? 0 : 7; |
universe@19 | 253 | } else { |
universe@19 | 254 | move->piece = getpiece(mstr[0]); |
universe@19 | 255 | if (mstr[2] == 'x') { |
universe@19 | 256 | move->capture = 1; |
universe@19 | 257 | if (move->piece) { |
universe@19 | 258 | /* capture (e.g. "Ndxf3") */ |
universe@19 | 259 | move->fromfile = fileidx(mstr[1]); |
universe@19 | 260 | } else { |
universe@19 | 261 | /* long notation capture (e.g. "e5xf6") */ |
universe@19 | 262 | move->piece = PAWN; |
universe@19 | 263 | move->fromfile = fileidx(mstr[0]); |
universe@19 | 264 | move->fromrow = rowidx(mstr[1]); |
universe@19 | 265 | } |
universe@19 | 266 | } else { |
universe@19 | 267 | /* long notation move (e.g. "Nc5a4") */ |
universe@19 | 268 | move->fromfile = fileidx(mstr[1]); |
universe@19 | 269 | move->fromrow = rowidx(mstr[2]); |
universe@19 | 270 | } |
universe@19 | 271 | move->tofile = fileidx(mstr[3]); |
universe@19 | 272 | move->torow = rowidx(mstr[4]); |
universe@19 | 273 | } |
universe@19 | 274 | } else if (len == 6) { |
universe@19 | 275 | /* long notation capture (e.g. "Nc5xf3") */ |
universe@19 | 276 | if (mstr[3] == 'x') { |
universe@19 | 277 | move->capture = 1; |
universe@19 | 278 | move->piece = getpiece(mstr[0]); |
universe@19 | 279 | move->fromfile = fileidx(mstr[1]); |
universe@19 | 280 | move->fromrow = rowidx(mstr[2]); |
universe@19 | 281 | move->tofile = fileidx(mstr[4]); |
universe@19 | 282 | move->torow = rowidx(mstr[5]); |
universe@19 | 283 | } |
universe@19 | 284 | } |
universe@19 | 285 | |
universe@19 | 286 | |
universe@19 | 287 | if (move->piece) { |
universe@19 | 288 | if (move->piece == PAWN && move->torow == (mycolor==WHITE?7:0) |
universe@19 | 289 | && !move->promotion) { |
universe@19 | 290 | return NEED_PROMOTION; |
universe@19 | 291 | } |
universe@19 | 292 | |
universe@19 | 293 | move->piece |= mycolor; |
universe@19 | 294 | if (move->fromfile == POS_UNSPECIFIED |
universe@19 | 295 | || move->fromrow == POS_UNSPECIFIED) { |
universe@19 | 296 | return getlocation(board, move); |
universe@19 | 297 | } else { |
universe@19 | 298 | return chkidx(move) ? VALID_MOVE_SYNTAX : INVALID_POSITION; |
universe@19 | 299 | } |
universe@19 | 300 | } else { |
universe@19 | 301 | return INVALID_MOVE_SYNTAX; |
universe@19 | 302 | } |
universe@19 | 303 | } |