libchess/chess.h

   1 /* vim:tw=78:ts=8:sw=4:set ft=c:  */
   2 /*
   3     Copyright (C) 2002-2015 Ben Kibbey <bjk@luxsci.net>
   4
   5     This program is free software; you can redistribute it and/or modify
   6     it under the terms of the GNU General Public License as published by
   7     the Free Software Foundation; either version 2 of the License, or
   8     (at your option) any later version.
   9
  10     This program is distributed in the hope that it will be useful,
  11     but WITHOUT ANY WARRANTY; without even the implied warranty of
  12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13     GNU General Public License for more details.
  14
  15     You should have received a copy of the GNU General Public License
  16     along with this program; if not, write to the Free Software
  17     Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18 */
  19 #ifndef CHESS_H
  20 #define CHESS_H
  21
  22 #define PGN_TIME_FORMAT "%Y.%m.%d"
  23 #define MAX_PGN_LINE_LEN 255
  24 #define MAX_SAN_MOVE_LEN 7
  25 #define MAX_PGN_NAG 8
  26
  27 #define VALIDRANK       VALIDFILE
  28 #define VALIDFILE(f)    (f >= 1 && f <= 8)
  29 #define RANKTOBOARD(r)  (8 - r)
  30 #define FILETOBOARD(c)  (c - 1)
  31 #define RANKTOINT(r)    (r - '0')
  32 #define FILETOINT(c)    (c - ('a' - 1))
  33 #define VALIDROW(r)     (r >= '1' && r <= '8')
  34 #define VALIDCOL(c)     (c >= 'a' && c <= 'h')
  35 #define INTTORANK(r)    (r + '0')
  36 #define INTTOFILE(f)    (f + ('a' - 1))
  37
  38 #define SET_FLAG(var, f)        (var |= f)
  39 #define CLEAR_FLAG(var, f)      (var &= ~(f))
  40 #define TOGGLE_FLAG(var, f)     (var ^= (f))
  41 #define TEST_FLAG(var, f)       (var & f)
  42
  43 enum {
  44     OPEN_SQUARE, PAWN, BISHOP, ROOK, KNIGHT, QUEEN, KING
  45 };
  46
  47 enum {
  48     WHITE, BLACK
  49 };
  50
  51 /* Game flags. */
  52 #define GF_PERROR               0x0001  /* Parse error for this game. */
  53 #define GF_ENPASSANT            0x0002  /* For En Passant validation. */
  54 #define GF_GAMEOVER             0x0004  /* End of game. */
  55 #define GF_WK_CASTLE            0x0008
  56 #define GF_WQ_CASTLE            0x0010
  57 #define GF_BK_CASTLE            0x0020
  58 #define GF_BQ_CASTLE            0x0040
  59 #define GF_BLACK_OPENING        0x0080
  60
  61 /*
  62  * The chess board.
  63  */
  64 typedef struct {
  65     unsigned char icon;         // The piece.
  66     unsigned char valid: 1,     // != 0 if this square is a valid move for the
  67                                 // selected piece.
  68                   enpassant: 1;
  69 } BOARD[8][8];
  70
  71 /*
  72  * PGN Roster tags.
  73  */
  74 typedef struct tags {
  75     char *name;         // Tag name.
  76     char *value;        // Tag value.
  77 } TAG;
  78
  79 /*
  80  * Move history.
  81  *
  82  * g.hp is the pointer to the current history which may be .rav for
  83  * Recursive Annotated Variations. The depth of recursion is kept track of in
  84  * g.ravlevel.
  85  */
  86 typedef struct history {
  87     char *move;                         // The SAN move text.
  88     char *comment;                      // Annotation for this move.
  89     unsigned char nag[MAX_PGN_NAG];     // Numeric Annotation Glyph.
  90     char *fen;                          // Of the current board.
  91     struct history **rav;               // Variation of the current move.
  92 } HISTORY;
  93
  94 /*
  95  * Keeps game state history for the root move.
  96  */
  97 typedef struct {
  98     char *fen;          // Game board state.
  99     unsigned short flags;
 100     unsigned short hindex;
 101     HISTORY **hp;       // Pointer to the root move.
 102 } RAV;
 103
 104 /*
 105  * This is an array of 'games' structures. One for each game in a file, or
 106  * the current game.
 107  */
 108 typedef struct game_s {
 109     TAG **tag;                  // Roster tags.
 110     HISTORY **history;          // Move history for this game.
 111     HISTORY **hp;               // History pointer pointing to the location
 112                                 // in *history used mainly for RAV.
 113     RAV *rav;                   // Saved game states for the root move of RAV.
 114     int ravlevel;               // An index to *rav.
 115     unsigned short hindex;      // Current move in *hp.
 116     unsigned short flags;       // Game flags.
 117     unsigned short oflags;      // Game flags for the previous move.
 118     unsigned char side: 1,      // This playing side. BLACK or WHITE.
 119                   turn: 1;      // BLACK or WHITE.
 120     unsigned short ply;         // Move count.
 121     void *data;                 /* User data associated with this game. Must
 122                                  * be freed by the user. */
 123     // internal validation state
 124     int validate;
 125     int done_fen_tag;
 126     int pgn_fen_tag;
 127     int capture;
 128     int castle;
 129     int check;
 130     int check_testing;
 131     int kfile;
 132     int krank;
 133     int okfile;
 134     int okrank;
 135     int validate_find;
 136 } *GAME;
 137
 138 /*
 139  * Global GAME array. pgn_new_game() appends to this array.
 140  */
 141 GAME *game;
 142
 143 /*
 144  * 'gindex' and 'gtotal' are the current and total number of games in 'game'.
 145  */
 146 int gindex, gtotal;
 147
 148 /*
 149  * Library configuration flags. These will affect all games.
 150  */
 151 typedef enum {
 152     /*
 153      * When pgn_write() is called to write a game, write reduced PGN format.
 154      * This will only write the seven tag roster and move text skipping any
 155      * annotation. The type for this flag is an int.
 156      */
 157     PGN_REDUCED,
 158
 159     /*
 160      * The number of full moves to write per line. If 0 then pgn_write() will
 161      * write as many as possible within 80 columns. The type for this flag
 162      * is an int.
 163      */
 164     PGN_MPL,
 165
 166     /*
 167      * Normally when a parse error occurs in a game the game is flagged with
 168      * GF_PERROR and the rest of the game is discarded and processing of the
 169      * next game is done. When set and a parse error occurs the rest of the
 170      * entire file will be discarded. The type for this flag is an int.
 171      */
 172     PGN_STOP_ON_ERROR,
 173
 174 #ifdef DEBUG
 175     /*
 176      * If the following is set to a value > 0 and DEBUG was defined
 177      * at compile time then debugging output will be written to
 178      * "libchess.debug" in the current directory.
 179      */
 180     PGN_DEBUG,
 181 #endif
 182
 183     /*
 184      * After PGN_PROGRESS amount of bytes have been read from a file, call
 185      * PGN_PROGRESS_FUNC. The type for PGN_PROGRESS is a long.
 186      * PGN_PROGRESS_FUNC is of type pgn_progress.
 187      */
 188     PGN_PROGRESS,
 189     PGN_PROGRESS_FUNC,
 190
 191     /*
 192      * If set to 1 and an opponent can attack a castling square the castling
 193      * move will not be a valid one.
 194      */
 195     PGN_STRICT_CASTLING,
 196 } pgn_config_flag;
 197
 198 /*
 199  * Errors returned from the following functions.
 200  */
 201 typedef enum {
 202     E_PGN_ERR = -1,
 203     E_PGN_OK,
 204     E_PGN_PARSE,
 205     E_PGN_AMBIGUOUS,
 206     E_PGN_INVALID
 207 } pgn_error_t;
 208
 209 typedef struct {
 210     FILE *fp;
 211     char *filename;
 212     char *tmpfile;      /* For appending. */
 213     int pipe;
 214 } PGN_FILE;
 215
 216 /*
 217  * The prototype of the PGN_PROGRESS_FUNC function pointer.
 218  */
 219 typedef void (*pgn_progress)(long size, long offset);
 220
 221 /*
 222  * Sets config flag 'f' to the next argument. Returns E_PGN_OK on success or
 223  * E_PGN_ERR if 'f' is an invalid flag or E_PGN_INVALID if 'val' is an invalid
 224  * flag value.
 225  */
 226 pgn_error_t pgn_config_set(pgn_config_flag f, ...);
 227
 228 /*
 229  * Gets the value of config flag 'f'. The next argument should be a pointer of
 230  * the config type which is set to the value of 'f'. Returns E_PGN_ERR if 'f'
 231  * is an invalid flag or E_PGN_OK on success.
 232  */
 233 pgn_error_t pgn_config_get(pgn_config_flag f, ...);
 234
 235 /*
 236  * Returns E_PGN_OK if 'filename' is a recognized compressed filetype or
 237  * E_PGN_ERR if not.
 238  */
 239 pgn_error_t pgn_is_compressed(const char *filename);
 240
 241 /*
 242  * Opens a file 'filename' with the given 'mode'. 'mode' should be "r" for
 243  * reading, "w" for writing (will truncate if the file exists) or "a" for
 244  * appending to an existing file or creating a new one. Returns E_PGN_OK on
 245  * success and sets 'result' to a file handle for use will the other file
 246  * functions or E_PGN_ERR if there is an error opening the file in which case
 247  * errno will be set to the error or E_PGN_INVALID if 'mode' is an invalid
 248  * mode or if 'filename' is not a regular file.
 249  */
 250 pgn_error_t pgn_open(const char *filename, const char *mode, PGN_FILE **result);
 251
 252 /*
 253  * Closes and free's a PGN file handle. Returns E_PGN_OK on success,
 254  * E_PGN_INVALID if 'pgn' is NULL, or E_PGN_ERR if rename() failed.
 255  */
 256 pgn_error_t pgn_close(PGN_FILE *pgn);
 257
 258 /*
 259  * Parses a PGN_FILE which was opened with pgn_open(). If 'pgn' is NULL then a
 260  * single empty game will be allocated. If there is a parsing error
 261  * E_PGN_PARSE is returned, if there was a memory allocation error E_PGN_ERR
 262  * is returned, otherwise E_PGN_OK is returned and the global 'gindex' is set
 263  * to the last parsed game in the file and the global 'gtotal' is set to the
 264  * total number of games in the file. The file should be closed with
 265  * pgn_close() after processing.
 266  */
 267 pgn_error_t pgn_parse(PGN_FILE *pgn);
 268
 269 /*
 270  * Allocates a new game and increments 'gtotal'. 'gindex' is then set to the
 271  * new game. Returns E_PGN_ERR if there was a memory allocation error or
 272  * E_PGN_OK on success.
 273  */
 274 pgn_error_t pgn_new_game();
 275
 276 /*
 277  * Writes a PGN formatted game 'g' to a file which was opened with pgn_open().
 278  * See 'pgn_config_flag' for output options. Returns E_PGN_ERR if there was a
 279  * memory allocation or write error and E_PGN_OK on success.
 280  */
 281 pgn_error_t pgn_write(PGN_FILE *pgn, GAME g);
 282
 283 /*
 284  * Frees all games in the global 'game' array. Returns nothing.
 285  */
 286 void pgn_free_all(void);
 287
 288 /*
 289  * Frees a single game 'g'. Returns nothing.
 290  */
 291 void pgn_free(GAME g);
 292
 293 /*
 294  * Adds a tag 'name' with value 'value' to the pointer to array of TAG
 295  * pointers 'dst'. If a duplicate tag 'name' was found then the existing tag
 296  * is updated to the new 'value'. If 'value' is NULL, the tag is removed.
 297  * Returns E_PGN_ERR if there was a memory allocation error or E_PGN_OK on
 298  * success.
 299  */
 300 pgn_error_t pgn_tag_add(TAG ***dst, char *name, char *value);
 301
 302 /*
 303  * Returns the total number of tags in 't' or 0 if 't' is NULL.
 304  */
 305 int pgn_tag_total(TAG **t);
 306
 307 /*
 308  * Finds a tag 'name' in the structure array 't'. Returns the location in the
 309  * array of the found tag or E_PGN_ERR if the tag could not be found.
 310  */
 311 pgn_error_t pgn_tag_find(TAG **t, const char *name);
 312
 313 /*
 314  * Sorts a tag array. The first seven tags are in order of the PGN standard so
 315  * don't sort'em. Returns nothing.
 316  */
 317 void pgn_tag_sort(TAG **t);
 318
 319 /*
 320  * Frees a TAG array. Returns nothing.
 321  */
 322 void pgn_tag_free(TAG **);
 323
 324 /*
 325  * It initializes the board (b) to the FEN tag (if found) and sets the
 326  * castling and enpassant info for the game 'g'. If 'fen' is set it should be
 327  * a fen tag and will be parsed rather than the game 'g'.tag FEN tag. Returns
 328  * E_PGN_OK on success or if there was both a FEN and SetUp tag with the SetUp
 329  * tag set to 0. Returns E_PGN_PARSE if there was a FEN parse error, E_PGN_ERR
 330  * if there was no FEN tag or there was a SetUp tag with a value of 0. Returns
 331  * E_PGN_OK on success.
 332  */
 333 pgn_error_t pgn_board_init_fen(GAME g, BOARD b, char *fen);
 334
 335 /*
 336  * Creates a FEN tag from the current game 'g', history move (g.hindex) and
 337  * board 'b'. Returns a FEN tag.
 338  */
 339 char *pgn_game_to_fen(GAME g, BOARD b);
 340
 341 /*
 342  * Resets or initializes a new game board 'b'. Returns nothing.
 343  */
 344 void pgn_board_init(BOARD b);
 345
 346 /*
 347  * Valididate move 'm' against the game state 'g' and game board 'b' and
 348  * update board 'b'. 'm' is ensured to be in SAN format and 'frfr' will the
 349  * file/rank representation of 'm' and should be freed. Returns E_PGN_PARSE if
 350  * there was a move text parsing error, E_PGN_INVALID if the move is invalid,
 351  * E_PGN_AMBIGUOUS if the move is invalid with ambiguities or E_PGN_OK if
 352  * successful.
 353  */
 354 pgn_error_t pgn_parse_move(GAME g, BOARD b, char **m, char **frfr);
 355
 356 /*
 357  * Like pgn_parse_move() but don't modify game flags in 'g' or board 'b'.
 358  */
 359 pgn_error_t pgn_validate_move(GAME g, BOARD b, char **m, char **frfr);
 360
 361 /*
 362  * Returns the total number of moves in 'h' or 0 if there are none.
 363  */
 364 int pgn_history_total(HISTORY **h);
 365
 366 /*
 367  * Returns the history ply 'n' from 'h'. If 'n' is out of range then NULL is
 368  * returned.
 369  */
 370 HISTORY *pgn_history_by_n(HISTORY **h, int n);
 371
 372 /*
 373  * Appends move 'm' to game 'g' history pointer and creates a FEN tag for the
 374  * current game state using board 'b'. The FEN tag makes things faster than
 375  * validating the entire move history by validating only the current move to
 376  * the previous moves FEN tag. The history pointer may be a in a RAV so
 377  * g->rav.hp is also updated to the new (realloc()'ed) pointer. If not in a
 378  * RAV then g->history will be updated. Returns E_PGN_ERR if realloc() failed
 379  * or E_PGN_OK on success.
 380  */
 381 pgn_error_t pgn_history_add(GAME g, BOARD b, const char *m);
 382
 383 /*
 384  * Deallocates all of the history data from position 'start' in the array 'h'.
 385  * Returns nothing.
 386  */
 387 void pgn_history_free(HISTORY **h, int start);
 388
 389 /*
 390  * Resets the game 'g' using board 'b' up to history move (g.hindex) 'n'.
 391  * Returns E_PGN_OK on success or E_PGN_PARSE if there was a FEN tag but the
 392  * parsing of it failed. Or returns E_PGN_INVALID if somehow the move failed
 393  * validation while resetting.
 394  */
 395 pgn_error_t pgn_board_update(GAME g, BOARD b, int n);
 396
 397 /*
 398  * Updates the game 'g' using board 'b' to the next 'n'th history move.
 399  * Returns nothing.
 400  */
 401 void pgn_history_prev(GAME g, BOARD b, int n);
 402
 403 /*
 404  * Updates the game 'g' using board 'b' to the previous 'n'th history move.
 405  * Returns nothing.
 406  */
 407 void pgn_history_next(GAME g, BOARD b, int n);
 408
 409 /*
 410  * Converts the character piece 'p' to an integer. Returns the integer
 411  * associated with 'p' or E_PGN_ERR if 'p' is invalid.
 412  */
 413 int pgn_piece_to_int(int p);
 414
 415 /*
 416  * Converts the integer piece 'n' to a character whose turn is 'turn'. WHITE
 417  * piece are uppercase and BLACK pieces are lowercase. Returns the character
 418  * associated with 'n' or E_PGN_ERR if 'n' is an invalid piece.
 419  */
 420 pgn_error_t pgn_int_to_piece(char turn, int n);
 421
 422 /*
 423  * Toggles g->turn. Returns nothing.
 424  */
 425 void pgn_switch_turn(GAME);
 426
 427 /*
 428  * Toggles g->side and switches the White and Black roster tags. Returns
 429  * nothing.
 430  */
 431 void pgn_switch_side(GAME g, int t);
 432
 433 /*
 434  * Clears the enpassant flag for all positions on board 'b'. Returns nothing.
 435  */
 436 void pgn_reset_enpassant(BOARD b);
 437
 438 /*
 439  * Clears the valid move flag for all positions on board 'b'. Returns nothing.
 440  */
 441 void pgn_reset_valid_moves(BOARD b);
 442
 443 /*
 444  * Sets valid moves (b.valid) from game 'g' using board 'b'. The valid moves
 445  * are for the piece on the board 'b' at 'rank' and 'file'. Returns nothing.
 446  */
 447 void pgn_find_valid_moves(GAME g, BOARD b, int rank, int file);
 448
 449 /*
 450  * Returns the version string of the library.
 451  */
 452 char *pgn_version(void);
 453
 454 #endif