terminal-chess: src/chess/rules.h@c6a1ad6cf749

     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>

    35 #define VALID_MOVE_SYNTAX   0

    36 #define INVALID_MOVE_SYNTAX 1

    37 #define INVALID_POSITION    2

    38 #define AMBIGUOUS_MOVE      3

    39 #define NEED_PROMOTION      4

    42 #define PIECE_MASK       0x0F

    43 #define COLOR_MASK       0x30

    44 #define ENPASSANT_THREAT 0x40

    46 #define WHITE 0x10

    47 #define BLACK 0x20

    49 #define PAWN   0x01

    50 #define ROOK   0x02

    51 #define KNIGHT 0x03

    52 #define BISHOP 0x04

    53 #define QUEEN  0x05

    54 #define KING   0x06

    56 #define WPAWN   (WHITE|PAWN)

    57 #define WROOK   (WHITE|ROOK)

    58 #define WKNIGHT (WHITE|KNIGHT)

    59 #define WBISHOP (WHITE|BISHOP)

    60 #define WQUEEN  (WHITE|QUEEN)

    61 #define WKING   (WHITE|KING)

    62 #define BPAWN   (BLACK|PAWN)

    63 #define BROOK   (BLACK|ROOK)

    64 #define BKNIGHT (BLACK|KNIGHT)

    65 #define BBISHOP (BLACK|BISHOP)

    66 #define BQUEEN  (BLACK|QUEEN)

    67 #define BKING   (BLACK|KING)

    69 typedef uint8_t Board[8][8];

    72 typedef struct {

    73     uint8_t piece;

    74     uint8_t fromfile;

    75     uint8_t fromrow;

    76     uint8_t tofile;

    77     uint8_t torow;

    78     uint8_t promotion;

    79     _Bool check;

    80     _Bool capture;

    81 } Move;

    83 typedef struct MoveList MoveList;

    85 struct MoveList {

    86     Move move;

    87     MoveList* next;

    88 };

    90 typedef struct {

    91     Board board;

    92     uint8_t mycolor;

    93     MoveList* movelist;

    94     MoveList* lastmove;

    95     _Bool checkmate;

    96     _Bool stalemate;

    97 } GameState;

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

   101 #define POS_UNSPECIFIED UINT8_MAX

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

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

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

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

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

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

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

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

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

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

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

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

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

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

   123 void gamestate_cleanup(GameState *gamestate);

   125 /**

   126  * Maps a character to a piece.

   127  *

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

   129  *

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

   131  * @return numeric value for the specified piece

   132  */

   133 uint8_t getpiece(char c);

   135 /**

   136  * Maps a piece to a character.

   137  *

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

   139  *

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

   141  * @return character value for the specified piece

   142  */

   143 char getpiecechr(uint8_t piece);

   145 /**

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

   147  *

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

   149  * must be set, too.

   150  *

   151  * @param gamestate the current game state

   152  * @param row row of the field to check

   153  * @param file file of the field to check

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

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

   156  * rare maximum of 16 elements)

   157  * @param threatcount a pointer to an uint8_t where to store the amount of threats

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

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

   160  */

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

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

   164 /**

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

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

   167  *

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

   169  * must be set, too.

   170  *

   171  * @param gamestate the current game state

   172  * @param row row of the field to check

   173  * @param file file of the field to check

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

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

   176  * rare maximum of 16 elements)

   177  * @param threatcount a pointer to an uint8_t where to store the amount of threats

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

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

   180  */

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

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

   184 /**

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

   186  *

   187  * @param gamestate the current game state

   188  * @param row row of the field to check

   189  * @param file file of the field to check

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

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

   192  * field

   193  */

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

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

   197 /**

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

   199  *

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

   201  * therefore able to perform the move.

   202  *

   203  * @param gamestate the current game state

   204  * @param row row of the field to check

   205  * @param file file of the field to check

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

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

   208  * field and could capture an opponent piece

   209  */

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

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

   213 /**

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

   215  *

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

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

   218  *

   219  * @param gamestate the current game state

   220  * @param row row of the field to check

   221  * @param file file of the field to check

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

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

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

   225  */

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

   227         uint8_t color);

   229 /**

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

   231  * object.

   232  *

   233  * @param gamestate the current game state

   234  * @param mstr the input string to parse

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

   236  * @return status code (see rules/rules.h for the list of codes)

   237  */

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

   240 /**

   241  * Validates move by applying chess rules.

   242  * @param gamestate the current game state

   243  * @param move the move to validate

   244  * @return TRUE, if the move complies to chess rules, FALSE otherwise

   245  */

   246 _Bool validate_move(GameState *gamestate, Move *move);

   248 /**

   249  * Applies a move and deletes captured pieces.

   250  *

   251  * @param gamestate the current game state

   252  * @param move the move to apply

   253  */

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

   256 #endif	/* RULES_H */

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src/chess/rules.h@c6a1ad6cf749

src/chess/rules.h