Mercurial > hg > terminal-chess / file revision
src/chess/rules.h@c8f2c280cff7
src/chess/rules.h
Tue, 18 Sep 2018 15:02:08 +0200
- author
- Mike Becker <universe@uap-core.de>
- date
- Tue, 18 Sep 2018 15:02:08 +0200
- changeset 69
- c8f2c280cff7
- parent 63
- 611332453da0
- permissions
- -rw-r--r--
adds unicode support
1 /*
2 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
3 *
4 * Copyright 2016 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 MoveList* movelist;
114 MoveList* lastmove;
115 unsigned int movecount; /* number of (half-)moves (counting BOTH colors) */
116 _Bool checkmate;
117 _Bool stalemate;
118 _Bool remis;
119 _Bool resign;
120 } GameState;
122 #define opponent_color(color) ((color)==WHITE?BLACK:WHITE)
124 #define POS_UNSPECIFIED UINT8_MAX
125 #define mdst(b,m) b[(m)->torow][(m)->tofile]
126 #define msrc(b,m) b[(m)->fromrow][(m)->fromfile]
128 #define isidx(idx) ((uint8_t)(idx) < 8)
130 #define isfile(file) (file >= 'a' && file <= 'h')
131 #define isrow(row) (row >= '1' && row <= '8')
133 #define rowidx(row) (row-'1')
134 #define fileidx(file) (file-'a')
136 #define rowchr(row) (row+'1')
137 #define filechr(file) (file+'a')
139 #define chkidx(move) (isidx((move)->fromfile) && isidx((move)->fromrow) && \
140 isidx((move)->tofile) && isidx((move)->torow))
142 /* secure versions - use, if index is not checked with isidx() */
143 #define fileidx_s(c) (isfile(c)?fileidx(c):POS_UNSPECIFIED)
144 #define rowidx_s(c) (isrow(c)?rowidx(c):POS_UNSPECIFIED)
146 #define is_game_running(gamestate) !((gamestate)->checkmate || \
147 (gamestate)->resign || (gamestate)->stalemate || (gamestate)->remis)
150 /**
151 * Initializes a game state and prepares the chess board.
152 * @param gamestate the game state to initialize
153 */
154 void gamestate_init(GameState *gamestate);
156 /**
157 * Cleans up a game state and frees the memory for the movement list.
158 * @param gamestate the game state to clean up
159 */
160 void gamestate_cleanup(GameState *gamestate);
162 /**
163 * Maps a character to a piece.
164 *
165 * Does not work for pawns, since they don't have a character.
166 *
167 * @param c one of R,N,B,Q,K
168 * @return numeric value for the specified piece
169 */
170 uint8_t getpiece(char c);
172 /**
173 * Maps a piece to a character.
174 *
175 * Does not work for pawns, scince they don't have a character.
176 *
177 * @param piece may have color or additional flags
178 * @return character value for the specified piece
179 */
180 char getpiecechr(uint8_t piece);
182 /**
183 * Maps a piece to a unicode character sequence.
184 *
185 * The returned unicode is for black pieces.
186 * You may colorize the output by setting the terminal foreground color.
187 *
188 * @param piece the piece to dispaly
189 * @return unicode character sequence for the specified piece
190 */
191 unsigned char* getpieceunicode(uint8_t piece);
193 /**
194 * Checks, if a specified field is covered by a piece of a certain color.
195 *
196 * The out-parameters may both be NULL, but if any of them is set, the other
197 * must be set, too.
198 *
199 * @param gamestate the current game state
200 * @param row row of the field to check
201 * @param file file of the field to check
202 * @param color the color of the piece that should threaten the field
203 * @param threats the array where to store the threats (should be able to hold
204 * the rare maximum of 16 elements)
205 * @param threatcount a pointer to an uint8_t where the count of threats is
206 * stored
207 * @return TRUE, if any piece of the specified color threatens the specified
208 * field (i.e. could capture an opponent piece)
209 */
210 _Bool get_threats(GameState *gamestate, uint8_t row, uint8_t file,
211 uint8_t color, Move* threats, uint8_t* threatcount);
213 /**
214 * Checks, if a specified field is covered by a piece of a certain color AND
215 * if this piece is not pinned and therefore able to perform the move.
216 *
217 * The out-parameters may both be NULL, but if any of them is set, the other
218 * must be set, too.
219 *
220 * @param gamestate the current game state
221 * @param row row of the field to check
222 * @param file file of the field to check
223 * @param color the color of the piece that should threaten the field
224 * @param threats the array where to store the threats (should be able to hold
225 * the rare maximum of 16 elements)
226 * @param threatcount a pointer to an uint8_t where the count of threats is
227 * stored
228 * @return TRUE, if any piece of the specified color threatens the specified
229 * field (i.e. could capture an opponent piece)
230 */
231 _Bool get_real_threats(GameState *gamestate, uint8_t row, uint8_t file,
232 uint8_t color, Move* threats, uint8_t* threatcount);
234 /**
235 * Checks, if a specified field is covered by a piece of a certain color.
236 *
237 * @param gamestate the current game state
238 * @param row row of the field to check
239 * @param file file of the field to check
240 * @param color the color of the piece that should cover the field
241 * @return TRUE, if any piece of the specified color threatens the specified
242 * field
243 */
244 #define is_covered(gamestate, row, file, color) \
245 get_threats(gamestate, row, file, color, NULL, NULL)
247 /**
248 * Checks, if a specified field is attacked by a piece of a certain color.
249 *
250 * I.e. the field is covered by a piece AND this piece is not pinned and
251 * therefore able to perform the move.
252 *
253 * @param gamestate the current game state
254 * @param row row of the field to check
255 * @param file file of the field to check
256 * @param color the color of the piece that should cover the field
257 * @return TRUE, if any piece of the specified color threatens the specified
258 * field and could capture an opponent piece
259 */
260 #define is_attacked(gamestate, row, file, color) \
261 get_real_threats(gamestate, row, file, color, NULL, NULL)
263 /**
264 * Checks, if a specified field is protected by a piece of a certain color.
265 *
266 * I.e. the field is covered by a piece that is NOT the king AND this piece is
267 * not pinned and therefore able to perform the move.
268 *
269 * @param gamestate the current game state
270 * @param row row of the field to check
271 * @param file file of the field to check
272 * @param color the color of the piece that should cover the field
273 * @return TRUE, if any piece (excluding the king) of the specified color
274 * threatens the specified field and could capture an opponent piece
275 */
276 _Bool is_protected(GameState *gamestate, uint8_t row, uint8_t file,
277 uint8_t color);
279 /**
280 * Checks, if the specified move cannot be performed, because the piece is
281 * either pinned or cannot remove the check.
282 *
283 * Note: in chess a piece is pinned, when it can't be moved because the move
284 * would result in a check position. But this function <u>also</u> returns true,
285 * if the king is already in check position and the specified move does not
286 * protect the king.
287 *
288 * @param gamestate the current game state
289 * @param move the move to check
290 * @return TRUE, if the move cannot be performed because the king would be in
291 * check after the move
292 */
293 _Bool is_pinned(GameState *gamestate, Move *move);
295 /**
296 * Evaluates a move syntactically and stores the move data in the specified
297 * object.
298 *
299 * @param gamestate the current game state
300 * @param mstr the input string to parse
301 * @param move a pointer to object where the move data shall be stored
302 * @param color the color of the player to evaluate the move for
303 * @return status code (see macros in this file for the list of codes)
304 */
305 int eval_move(GameState *gamestate, char *mstr, Move *move, uint8_t color);
307 /**
308 * Validates move by applying chess rules.
309 * @param gamestate the current game state
310 * @param move the move to validate
311 * @return status code (see macros in this file for the list of codes)
312 */
313 int validate_move(GameState *gamestate, Move *move);
315 /**
316 * Applies a move and deletes captured pieces.
317 *
318 * @param gamestate the current game state
319 * @param move the move to apply
320 */
321 void apply_move(GameState *gamestate, Move *move);
324 /**
325 * Returns the remaining time on the clock for the specified player.
326 *
327 * @param gameinfo the information about the game
328 * @param gamestate the current game state
329 * @param color either BLACK or WHITE
330 * @return the remaining time - if time control is disabled, this function
331 * always returns zero
332 */
333 uint16_t remaining_movetime(GameInfo *gameinfo, GameState *gamestate,
334 uint8_t color);
336 #endif /* RULES_H */
