terminal-chess: src/chess/rules.h@02c509a44e98

     1 /*

     2  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.

     3  *

     4  * Copyright 2014 Mike Becker. All rights reserved.

     5  *

     6  * Redistribution and use in source and binary forms, with or without

     7  * modification, are permitted provided that the following conditions are met:

     8  *

     9  *   1. Redistributions of source code must retain the above copyright

    10  *      notice, this list of conditions and the following disclaimer.

    11  *

    12  *   2. Redistributions in binary form must reproduce the above copyright

    13  *      notice, this list of conditions and the following disclaimer in the

    14  *      documentation and/or other materials provided with the distribution.

    15  *

    16  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"

    17  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

    18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

    19  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE

    20  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR

    21  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF

    22  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS

    23  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN

    24  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

    25  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE

    26  * POSSIBILITY OF SUCH DAMAGE.

    27  *

    28  */

    30 #ifndef RULES_H

    31 #define	RULES_H

    33 #include <stdint.h>

    34 #include <sys/time.h>

    36 #define VALID_MOVE_SYNTAX      0

    37 #define VALID_MOVE_SEMANTICS   0 /* use same code for a success */

    38 #define INVALID_MOVE_SYNTAX    1

    39 #define INVALID_POSITION       2

    40 #define AMBIGUOUS_MOVE         3

    41 #define NEED_PROMOTION         4

    42 #define PIECE_PINNED           5

    43 #define KING_IN_CHECK          6

    44 #define KING_MOVES_INTO_CHECK  7

    45 #define RULES_VIOLATED        10

    48 #define PIECE_MASK       0x0F

    49 #define COLOR_MASK       0x30

    50 #define ENPASSANT_THREAT 0x40

    52 #define WHITE 0x10

    53 #define BLACK 0x20

    55 #define PAWN   0x01

    56 #define ROOK   0x02

    57 #define KNIGHT 0x03

    58 #define BISHOP 0x04

    59 #define QUEEN  0x05

    60 #define KING   0x06

    62 #define WPAWN   (WHITE|PAWN)

    63 #define WROOK   (WHITE|ROOK)

    64 #define WKNIGHT (WHITE|KNIGHT)

    65 #define WBISHOP (WHITE|BISHOP)

    66 #define WQUEEN  (WHITE|QUEEN)

    67 #define WKING   (WHITE|KING)

    68 #define BPAWN   (BLACK|PAWN)

    69 #define BROOK   (BLACK|ROOK)

    70 #define BKNIGHT (BLACK|KNIGHT)

    71 #define BBISHOP (BLACK|BISHOP)

    72 #define BQUEEN  (BLACK|QUEEN)

    73 #define BKING   (BLACK|KING)

    75 typedef uint8_t Board[8][8];

    77 struct movetimeval {

    78     uint64_t tv_sec;

    79     int32_t tv_usec;

    80 };

    82 typedef struct {

    83     uint8_t piece;

    84     uint8_t fromfile;

    85     uint8_t fromrow;

    86     uint8_t tofile;

    87     uint8_t torow;

    88     uint8_t promotion;

    89     uint8_t check;

    90     uint8_t capture;

    91     struct movetimeval timestamp;

    92     struct movetimeval movetime;

    93     char string[8];

    94 } Move;

    96 typedef struct MoveList MoveList;

    98 struct MoveList {

    99     Move move;

   100     MoveList* next;

   101 };

   104 typedef struct {

   105     uint8_t servercolor;

   106     uint8_t timecontrol;

   107     uint16_t time;

   108     uint16_t addtime;

   109 } GameInfo;

   111 typedef struct {

   112     Board board;

   113     uint8_t mycolor;

   114     MoveList* movelist;

   115     MoveList* lastmove;

   116     _Bool checkmate;

   117     _Bool stalemate;

   118 } GameState;

   120 #define opponent_color(color) ((color)==WHITE?BLACK:WHITE)

   122 #define POS_UNSPECIFIED UINT8_MAX

   123 #define mdst(b,m) b[(m)->torow][(m)->tofile]

   124 #define msrc(b,m) b[(m)->fromrow][(m)->fromfile]

   126 #define isidx(idx) ((uint8_t)(idx) < 8)

   128 #define isfile(file) (file >= 'a' && file <= 'h')

   129 #define isrow(row) (row >= '1' && row <= '8')

   131 #define rowidx(row) (row-'1')

   132 #define fileidx(file) (file-'a')

   134 #define rowchr(row) (row+'1')

   135 #define filechr(file) (file+'a')

   137 #define chkidx(move) (isidx((move)->fromfile) && isidx((move)->fromrow) && \

   138         isidx((move)->tofile) && isidx((move)->torow))

   140 /* secure versions - use, if index is not checked with isidx() */

   141 #define fileidx_s(c) (isfile(c)?fileidx(c):POS_UNSPECIFIED)

   142 #define rowidx_s(c) (isrow(c)?rowidx(c):POS_UNSPECIFIED)

   144 /**

   145  * Cleans up a game state and frees the memory for the movement list.

   146  * @param gamestate the game state to clean up

   147  */

   148 void gamestate_cleanup(GameState *gamestate);

   150 /**

   151  * Maps a character to a piece.

   152  *

   153  * Does not work for pawns, since they don't have a character.

   154  *

   155  * @param c one of R,N,B,Q,K

   156  * @return numeric value for the specified piece

   157  */

   158 uint8_t getpiece(char c);

   160 /**

   161  * Maps a piece to a character.

   162  *

   163  * Does not work for pawns, scince they don't have a character.

   164  *

   165  * @param piece one of ROOK, KNIGHT, BISHOP, QUEEN, KING

   166  * @return character value for the specified piece

   167  */

   168 char getpiecechr(uint8_t piece);

   170 /**

   171  * Checks, if a specified field is covered by a piece of a certain color.

   172  *

   173  * The out-parameters may both be NULL, but if any of them is set, the other

   174  * must be set, too.

   175  *

   176  * @param gamestate the current game state

   177  * @param row row of the field to check

   178  * @param file file of the field to check

   179  * @param color the color of the piece that should threaten the field

   180  * @param threats the array where to store the threats (should be able to hold

   181  * the rare maximum of 16 elements)

   182  * @param threatcount a pointer to an uint8_t where the count of threats is

   183  * stored

   184  * @return TRUE, if any piece of the specified color threatens the specified

   185  * field (i.e. could capture an opponent piece)

   186  */

   187 _Bool get_threats(GameState *gamestate, uint8_t row, uint8_t file,

   188         uint8_t color, Move* threats, uint8_t* threatcount);

   190 /**

   191  * Checks, if a specified field is covered by a piece of a certain color AND

   192  * if this piece is not pinned and therefore able to perform the move.

   193  *

   194  * The out-parameters may both be NULL, but if any of them is set, the other

   195  * must be set, too.

   196  *

   197  * @param gamestate the current game state

   198  * @param row row of the field to check

   199  * @param file file of the field to check

   200  * @param color the color of the piece that should threaten the field

   201  * @param threats the array where to store the threats (should be able to hold

   202  * the rare maximum of 16 elements)

   203  * @param threatcount a pointer to an uint8_t where the count of threats is

   204  * stored

   205  * @return TRUE, if any piece of the specified color threatens the specified

   206  * field (i.e. could capture an opponent piece)

   207  */

   208 _Bool get_real_threats(GameState *gamestate, uint8_t row, uint8_t file,

   209         uint8_t color, Move* threats, uint8_t* threatcount);

   211 /**

   212  * Checks, if a specified field is covered by a piece of a certain color.

   213  *

   214  * @param gamestate the current game state

   215  * @param row row of the field to check

   216  * @param file file of the field to check

   217  * @param color the color of the piece that should cover the field

   218  * @return TRUE, if any piece of the specified color threatens the specified

   219  * field

   220  */

   221 #define is_covered(gamestate, row, file, color) \

   222     get_threats(gamestate, row, file, color, NULL, NULL)

   224 /**

   225  * Checks, if a specified field is attacked by a piece of a certain color.

   226  *

   227  * I.e. the field is covered by a piece AND this piece is not pinned and

   228  * therefore able to perform the move.

   229  *

   230  * @param gamestate the current game state

   231  * @param row row of the field to check

   232  * @param file file of the field to check

   233  * @param color the color of the piece that should cover the field

   234  * @return TRUE, if any piece of the specified color threatens the specified

   235  * field and could capture an opponent piece

   236  */

   237 #define is_attacked(gamestate, row, file, color) \

   238     get_threats(gamestate, row, file, color, NULL, NULL)

   240 /**

   241  * Checks, if a specified field is protected by a piece of a certain color.

   242  *

   243  * I.e. the field is covered by a piece that is NOT the king AND this piece is

   244  * not pinned and therefore able to perform the move.

   245  *

   246  * @param gamestate the current game state

   247  * @param row row of the field to check

   248  * @param file file of the field to check

   249  * @param color the color of the piece that should cover the field

   250  * @return TRUE, if any piece (excluding the king) of the specified color

   251  * threatens the specified field and could capture an opponent piece

   252  */

   253 _Bool is_protected(GameState *gamestate, uint8_t row, uint8_t file,

   254         uint8_t color);

   256 /**

   257  * Checks, if the specified move cannot be performed, because the piece is

   258  * either pinned or cannot remove the check.

   259  *

   260  * Note: in chess a piece is pinned, when it can't be moved because the move

   261  * would result in a check position. But this function <u>also</u> returns true,

   262  * if the king is already in check position and the specified move does not

   263  * protect the king.

   264  *

   265  * @param gamestate the current game state

   266  * @param move the move to check

   267  * @return TRUE, if the move cannot be performed because the king would be in

   268  * check after the move

   269  */

   270 _Bool is_pinned(GameState *gamestate, Move *move);

   272 /**

   273  * Evaluates a move syntactically and stores the move data in the specified

   274  * object.

   275  *

   276  * @param gamestate the current game state

   277  * @param mstr the input string to parse

   278  * @param move a pointer to object where the move data shall be stored

   279  * @return status code (see macros in this file for the list of codes)

   280  */

   281 int eval_move(GameState *gamestate, char *mstr, Move *move);

   283 /**

   284  * Validates move by applying chess rules.

   285  * @param gamestate the current game state

   286  * @param move the move to validate

   287  * @return status code (see macros in this file for the list of codes)

   288  */

   289 int validate_move(GameState *gamestate, Move *move);

   291 /**

   292  * Applies a move and deletes captured pieces.

   293  *

   294  * @param gamestate the current game state

   295  * @param move the move to apply

   296  */

   297 void apply_move(GameState *gamestate, Move *move);

   300 /**

   301  * Returns the remaining time on the clock for the specified player.

   302  *

   303  * @param gameinfo the information about the game

   304  * @param gamestate the current game state

   305  * @param color either BLACK or WHITE

   306  * @return the remaining time - if time control is disabled, this function

   307  * always returns zero

   308  */

   309 uint16_t remaining_movetime(GameInfo *gameinfo, GameState *gamestate,

   310         uint8_t color);

   312 #endif	/* RULES_H */

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src/chess/rules.h@02c509a44e98

src/chess/rules.h