Mercurial > hg > terminal-chess / file revision
src/chess/rules.c@41017d0a72c5
src/chess/rules.c
Mon, 16 Jun 2014 13:45:31 +0200
- author
- Mike Becker <universe@uap-core.de>
- date
- Mon, 16 Jun 2014 13:45:31 +0200
- changeset 50
- 41017d0a72c5
- parent 49
- 02c509a44e98
- child 51
- 84f2e380a434
- permissions
- -rw-r--r--
added pgn parser and writer (without comment support yet) + minor refactorings
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 #include "rules.h"
31 #include "chess.h"
32 #include <string.h>
33 #include <stdlib.h>
34 #include <sys/time.h>
36 static GameState gamestate_copy_sim(GameState *gamestate) {
37 GameState simulation = *gamestate;
38 if (simulation.lastmove) {
39 MoveList *lastmovecopy = malloc(sizeof(MoveList));
40 *lastmovecopy = *(simulation.lastmove);
41 simulation.movelist = simulation.lastmove = lastmovecopy;
42 }
44 return simulation;
45 }
47 void gamestate_init(GameState *gamestate) {
48 memset(gamestate, 0, sizeof(GameState));
50 Board initboard = {
51 {WROOK, WKNIGHT, WBISHOP, WQUEEN, WKING, WBISHOP, WKNIGHT, WROOK},
52 {WPAWN, WPAWN, WPAWN, WPAWN, WPAWN, WPAWN, WPAWN, WPAWN},
53 {0, 0, 0, 0, 0, 0, 0, 0},
54 {0, 0, 0, 0, 0, 0, 0, 0},
55 {0, 0, 0, 0, 0, 0, 0, 0},
56 {0, 0, 0, 0, 0, 0, 0, 0},
57 {BPAWN, BPAWN, BPAWN, BPAWN, BPAWN, BPAWN, BPAWN, BPAWN},
58 {BROOK, BKNIGHT, BBISHOP, BQUEEN, BKING, BBISHOP, BKNIGHT, BROOK}
59 };
60 memcpy(gamestate->board, initboard, sizeof(Board));
61 }
63 void gamestate_cleanup(GameState *gamestate) {
64 MoveList *elem;
65 elem = gamestate->movelist;
66 while (elem) {
67 MoveList *cur = elem;
68 elem = elem->next;
69 free(cur);
70 };
71 }
73 /* MUST be called IMMEDIATLY after applying a move to work correctly */
74 static void format_move(GameState *gamestate, Move *move) {
75 char *string = move->string;
77 /* at least 8 characters should be available, wipe them out */
78 memset(string, 0, 8);
80 /* special formats for castling */
81 if ((move->piece&PIECE_MASK) == KING &&
82 abs(move->tofile-move->fromfile) == 2) {
83 if (move->tofile==fileidx('c')) {
84 memcpy(string, "O-O-O", 5);
85 } else {
86 memcpy(string, "O-O", 3);
87 }
88 }
90 /* start by notating the piece character */
91 string[0] = getpiecechr(move->piece);
92 int idx = string[0] ? 1 : 0;
94 /* find out how many source information we do need */
95 uint8_t piece = move->piece & PIECE_MASK;
96 if (piece == PAWN) {
97 if (move->capture) {
98 string[idx++] = filechr(move->fromfile);
99 }
100 } else if (piece != KING) {
101 Move threats[16];
102 uint8_t threatcount;
103 get_real_threats(gamestate, move->torow, move->tofile,
104 move->piece&COLOR_MASK, threats, &threatcount);
105 if (threatcount > 1) {
106 int ambrows = 0, ambfiles = 0;
107 for (uint8_t i = 0 ; i < threatcount ; i++) {
108 if (threats[i].fromrow == move->fromrow) {
109 ambrows++;
110 }
111 if (threats[i].fromfile == move->fromfile) {
112 ambfiles++;
113 }
114 }
115 /* ambiguous row, name file */
116 if (ambrows > 1) {
117 string[idx++] = filechr(move->fromfile);
118 }
119 /* ambiguous file, name row */
120 if (ambfiles > 1) {
121 string[idx++] = filechr(move->fromrow);
122 }
123 }
124 }
126 /* capturing? */
127 if (move->capture) {
128 string[idx++] = 'x';
129 }
131 /* destination */
132 string[idx++] = filechr(move->tofile);
133 string[idx++] = rowchr(move->torow);
135 /* promotion? */
136 if (move->promotion) {
137 string[idx++] = '=';
138 string[idx++] = getpiecechr(move->promotion);
139 }
141 /* check? */
142 if (move->check) {
143 /* works only, if this function is called when applying the move */
144 string[idx++] = gamestate->checkmate?'#':'+';
145 }
146 }
148 static void addmove(GameState* gamestate, Move *move) {
149 MoveList *elem = malloc(sizeof(MoveList));
150 elem->next = NULL;
151 elem->move = *move;
153 struct timeval curtimestamp;
154 gettimeofday(&curtimestamp, NULL);
155 elem->move.timestamp.tv_sec = curtimestamp.tv_sec;
156 elem->move.timestamp.tv_usec = curtimestamp.tv_usec;
158 if (gamestate->lastmove) {
159 struct movetimeval *lasttstamp = &(gamestate->lastmove->move.timestamp);
160 uint64_t sec = curtimestamp.tv_sec - lasttstamp->tv_sec;
161 suseconds_t micros;
162 if (curtimestamp.tv_usec < lasttstamp->tv_usec) {
163 micros = 1e6L-(lasttstamp->tv_usec - curtimestamp.tv_usec);
164 sec--;
165 } else {
166 micros = curtimestamp.tv_usec - lasttstamp->tv_usec;
167 }
169 elem->move.movetime.tv_sec = sec;
170 elem->move.movetime.tv_usec = micros;
172 gamestate->lastmove->next = elem;
173 gamestate->lastmove = elem;
174 } else {
175 elem->move.movetime.tv_usec = 0;
176 elem->move.movetime.tv_sec = 0;
177 gamestate->movelist = gamestate->lastmove = elem;
178 }
179 }
181 char getpiecechr(uint8_t piece) {
182 switch (piece & PIECE_MASK) {
183 case ROOK: return 'R';
184 case KNIGHT: return 'N';
185 case BISHOP: return 'B';
186 case QUEEN: return 'Q';
187 case KING: return 'K';
188 default: return '\0';
189 }
190 }
192 uint8_t getpiece(char c) {
193 switch (c) {
194 case 'R': return ROOK;
195 case 'N': return KNIGHT;
196 case 'B': return BISHOP;
197 case 'Q': return QUEEN;
198 case 'K': return KING;
199 default: return 0;
200 }
201 }
203 static void apply_move_impl(GameState *gamestate, Move *move, _Bool simulate) {
204 uint8_t piece = move->piece & PIECE_MASK;
205 uint8_t color = move->piece & COLOR_MASK;
207 /* en passant capture */
208 if (move->capture && piece == PAWN &&
209 mdst(gamestate->board, move) == 0) {
210 gamestate->board[move->fromrow][move->tofile] = 0;
211 }
213 /* remove old en passant threats */
214 for (uint8_t file = 0 ; file < 8 ; file++) {
215 gamestate->board[3][file] &= ~ENPASSANT_THREAT;
216 gamestate->board[4][file] &= ~ENPASSANT_THREAT;
217 }
219 /* add new en passant threat */
220 if (piece == PAWN && (
221 (move->fromrow == 1 && move->torow == 3) ||
222 (move->fromrow == 6 && move->torow == 4))) {
223 move->piece |= ENPASSANT_THREAT;
224 }
226 /* move (and maybe capture or promote) */
227 msrc(gamestate->board, move) = 0;
228 if (move->promotion) {
229 mdst(gamestate->board, move) = move->promotion;
230 } else {
231 mdst(gamestate->board, move) = move->piece;
232 }
234 /* castling */
235 if (piece == KING && move->fromfile == fileidx('e')) {
237 if (move->tofile == fileidx('g')) {
238 gamestate->board[move->torow][fileidx('h')] = 0;
239 gamestate->board[move->torow][fileidx('f')] = color|ROOK;
240 } else if (move->tofile == fileidx('c')) {
241 gamestate->board[move->torow][fileidx('a')] = 0;
242 gamestate->board[move->torow][fileidx('d')] = color|ROOK;
243 }
244 }
246 if (!simulate) {
247 if (!move->string[0]) {
248 format_move(gamestate, move);
249 }
250 }
251 /* add move, even in simulation (checkmate test needs it) */
252 addmove(gamestate, move);
253 }
255 void apply_move(GameState *gamestate, Move *move) {
256 apply_move_impl(gamestate, move, 0);
257 }
259 static int validate_move_rules(GameState *gamestate, Move *move) {
260 /* validate indices (don't trust opponent) */
261 if (!chkidx(move)) {
262 return INVALID_POSITION;
263 }
265 /* must move */
266 if (move->fromfile == move->tofile && move->fromrow == move->torow) {
267 return INVALID_MOVE_SYNTAX;
268 }
270 /* does piece exist */
271 if ((msrc(gamestate->board, move)&(PIECE_MASK|COLOR_MASK))
272 != (move->piece&(PIECE_MASK|COLOR_MASK))) {
273 return INVALID_POSITION;
274 }
276 /* can't capture own pieces */
277 if ((mdst(gamestate->board, move) & COLOR_MASK)
278 == (move->piece & COLOR_MASK)) {
279 return RULES_VIOLATED;
280 }
282 /* must capture, if and only if destination is occupied */
283 if ((mdst(gamestate->board, move) == 0 && move->capture) ||
284 (mdst(gamestate->board, move) != 0 && !move->capture)) {
285 return INVALID_MOVE_SYNTAX;
286 }
288 /* validate individual rules */
289 _Bool chkrules;
290 switch (move->piece & PIECE_MASK) {
291 case PAWN:
292 chkrules = pawn_chkrules(gamestate, move) &&
293 !pawn_isblocked(gamestate, move);
294 break;
295 case ROOK:
296 chkrules = rook_chkrules(move) &&
297 !rook_isblocked(gamestate, move);
298 break;
299 case KNIGHT:
300 chkrules = knight_chkrules(move); /* knight is never blocked */
301 break;
302 case BISHOP:
303 chkrules = bishop_chkrules(move) &&
304 !bishop_isblocked(gamestate, move);
305 break;
306 case QUEEN:
307 chkrules = queen_chkrules(move) &&
308 !queen_isblocked(gamestate, move);
309 break;
310 case KING:
311 chkrules = king_chkrules(gamestate, move) &&
312 !king_isblocked(gamestate, move);
313 break;
314 default:
315 return INVALID_MOVE_SYNTAX;
316 }
318 return chkrules ? VALID_MOVE_SEMANTICS : RULES_VIOLATED;
319 }
321 int validate_move(GameState *gamestate, Move *move) {
323 int result = validate_move_rules(gamestate, move);
325 /* cancel processing to save resources */
326 if (result != VALID_MOVE_SEMANTICS) {
327 return result;
328 }
330 /* find kings for check validation */
331 uint8_t piececolor = (move->piece & COLOR_MASK);
333 uint8_t mykingfile = 0, mykingrow = 0, opkingfile = 0, opkingrow = 0;
334 for (uint8_t row = 0 ; row < 8 ; row++) {
335 for (uint8_t file = 0 ; file < 8 ; file++) {
336 if (gamestate->board[row][file] ==
337 (piececolor == WHITE?WKING:BKING)) {
338 mykingfile = file;
339 mykingrow = row;
340 } else if (gamestate->board[row][file] ==
341 (piececolor == WHITE?BKING:WKING)) {
342 opkingfile = file;
343 opkingrow = row;
344 }
345 }
346 }
348 /* simulate move for check validation */
349 GameState simulation = gamestate_copy_sim(gamestate);
350 Move simmove = *move;
351 apply_move_impl(&simulation, &simmove, 1);
353 /* don't move into or stay in check position */
354 if (is_covered(&simulation, mykingrow, mykingfile,
355 opponent_color(piececolor))) {
357 gamestate_cleanup(&simulation);
358 if ((move->piece & PIECE_MASK) == KING) {
359 return KING_MOVES_INTO_CHECK;
360 } else {
361 /* last move is always not null in this case */
362 return gamestate->lastmove->move.check ?
363 KING_IN_CHECK : PIECE_PINNED;
364 }
365 }
367 /* correct check and checkmate flags (move is still valid) */
368 Move threats[16];
369 uint8_t threatcount;
370 move->check = get_threats(&simulation, opkingrow, opkingfile,
371 piececolor, threats, &threatcount);
373 if (move->check) {
374 /* determine possible escape fields */
375 _Bool canescape = 0;
376 for (int dr = -1 ; dr <= 1 && !canescape ; dr++) {
377 for (int df = -1 ; df <= 1 && !canescape ; df++) {
378 if (!(dr == 0 && df == 0) &&
379 isidx(opkingrow + dr) && isidx(opkingfile + df)) {
381 /* escape field neither blocked nor covered */
382 if ((simulation.board[opkingrow + dr][opkingfile + df]
383 & COLOR_MASK) != opponent_color(piececolor)) {
384 canescape |= !is_covered(&simulation,
385 opkingrow + dr, opkingfile + df, piececolor);
386 }
387 }
388 }
389 }
390 /* can't escape, can he capture? */
391 if (!canescape && threatcount == 1) {
392 canescape = is_attacked(&simulation, threats[0].fromrow,
393 threats[0].fromfile, opponent_color(piececolor));
394 }
396 /* can't capture, can he block? */
397 if (!canescape && threatcount == 1) {
398 Move *threat = &(threats[0]);
399 uint8_t threatpiece = threat->piece & PIECE_MASK;
401 /* knight, pawns and the king cannot be blocked */
402 if (threatpiece == BISHOP || threatpiece == ROOK
403 || threatpiece == QUEEN) {
404 if (threat->fromrow == threat->torow) {
405 /* rook aspect (on row) */
406 int d = threat->tofile > threat->fromfile ? 1 : -1;
407 uint8_t file = threat->fromfile;
408 while (!canescape && file != threat->tofile - d) {
409 file += d;
410 canescape |= is_protected(&simulation,
411 threat->torow, file, opponent_color(piececolor));
412 }
413 } else if (threat->fromfile == threat->tofile) {
414 /* rook aspect (on file) */
415 int d = threat->torow > threat->fromrow ? 1 : -1;
416 uint8_t row = threat->fromrow;
417 while (!canescape && row != threat->torow - d) {
418 row += d;
419 canescape |= is_protected(&simulation,
420 row, threat->tofile, opponent_color(piececolor));
421 }
422 } else {
423 /* bishop aspect */
424 int dr = move->torow > move->fromrow ? 1 : -1;
425 int df = move->tofile > move->fromfile ? 1 : -1;
427 uint8_t row = move->fromrow;
428 uint8_t file = move->fromfile;
429 while (!canescape && file != move->tofile - df
430 && row != move->torow - dr) {
431 row += dr;
432 file += df;
433 canescape |= is_protected(&simulation, row, file,
434 opponent_color(piececolor));
435 }
436 }
437 }
438 }
440 if (!canescape) {
441 gamestate->checkmate = 1;
442 }
443 }
445 gamestate_cleanup(&simulation);
447 return VALID_MOVE_SEMANTICS;
448 }
450 _Bool get_threats(GameState *gamestate, uint8_t row, uint8_t file,
451 uint8_t color, Move *threats, uint8_t *threatcount) {
452 Move candidates[32];
453 int candidatecount = 0;
454 for (uint8_t r = 0 ; r < 8 ; r++) {
455 for (uint8_t f = 0 ; f < 8 ; f++) {
456 if ((gamestate->board[r][f] & COLOR_MASK) == color) {
457 // non-capturing move
458 memset(&(candidates[candidatecount]), 0, sizeof(Move));
459 candidates[candidatecount].piece = gamestate->board[r][f];
460 candidates[candidatecount].fromrow = r;
461 candidates[candidatecount].fromfile = f;
462 candidates[candidatecount].torow = row;
463 candidates[candidatecount].tofile = file;
464 candidatecount++;
466 // capturing move
467 memcpy(&(candidates[candidatecount]),
468 &(candidates[candidatecount-1]), sizeof(Move));
469 candidates[candidatecount].capture = 1;
470 candidatecount++;
471 }
472 }
473 }
475 if (threatcount) {
476 *threatcount = 0;
477 }
480 _Bool result = 0;
482 for (int i = 0 ; i < candidatecount ; i++) {
483 if (validate_move_rules(gamestate, &(candidates[i]))
484 == VALID_MOVE_SEMANTICS) {
485 result = 1;
486 if (threats && threatcount) {
487 threats[(*threatcount)++] = candidates[i];
488 }
489 }
490 }
492 return result;
493 }
495 _Bool is_pinned(GameState *gamestate, Move *move) {
496 uint8_t color = move->piece & COLOR_MASK;
498 uint8_t kingfile = 0, kingrow = 0;
499 for (uint8_t row = 0 ; row < 8 ; row++) {
500 for (uint8_t file = 0 ; file < 8 ; file++) {
501 if (gamestate->board[row][file] == (color|KING)) {
502 kingfile = file;
503 kingrow = row;
504 }
505 }
506 }
508 GameState simulation = gamestate_copy_sim(gamestate);
509 Move simmove = *move;
510 apply_move(&simulation, &simmove);
511 _Bool covered = is_covered(&simulation,
512 kingrow, kingfile, opponent_color(color));
513 gamestate_cleanup(&simulation);
515 return covered;
516 }
518 _Bool get_real_threats(GameState *gamestate, uint8_t row, uint8_t file,
519 uint8_t color, Move *threats, uint8_t *threatcount) {
521 if (threatcount) {
522 *threatcount = 0;
523 }
525 Move candidates[16];
526 uint8_t candidatecount;
527 if (get_threats(gamestate, row, file, color, candidates, &candidatecount)) {
529 _Bool result = 0;
530 uint8_t kingfile = 0, kingrow = 0;
531 for (uint8_t row = 0 ; row < 8 ; row++) {
532 for (uint8_t file = 0 ; file < 8 ; file++) {
533 if (gamestate->board[row][file] == (color|KING)) {
534 kingfile = file;
535 kingrow = row;
536 }
537 }
538 }
540 for (uint8_t i = 0 ; i < candidatecount ; i++) {
541 GameState simulation = gamestate_copy_sim(gamestate);
542 Move simmove = candidates[i];
543 apply_move(&simulation, &simmove);
544 if (!is_covered(&simulation, kingrow, kingfile,
545 opponent_color(color))) {
546 result = 1;
547 if (threats && threatcount) {
548 threats[(*threatcount)++] = candidates[i];
549 }
550 }
551 }
553 return result;
554 } else {
555 return 0;
556 }
557 }
559 static int getlocation(GameState *gamestate, Move *move) {
561 uint8_t color = move->piece & COLOR_MASK;
562 _Bool incheck = gamestate->lastmove?gamestate->lastmove->move.check:0;
564 Move threats[16], *threat = NULL;
565 uint8_t threatcount;
567 if (get_threats(gamestate, move->torow, move->tofile, color,
568 threats, &threatcount)) {
570 int reason = INVALID_POSITION;
572 // find threats for the specified position
573 for (uint8_t i = 0 ; i < threatcount ; i++) {
574 if ((threats[i].piece & (PIECE_MASK | COLOR_MASK))
575 == move->piece &&
576 (move->fromrow == POS_UNSPECIFIED ||
577 move->fromrow == threats[i].fromrow) &&
578 (move->fromfile == POS_UNSPECIFIED ||
579 move->fromfile == threats[i].fromfile)) {
581 if (threat) {
582 return AMBIGUOUS_MOVE;
583 } else {
584 // found threat is no real threat
585 if (is_pinned(gamestate, &(threats[i]))) {
586 reason = incheck?KING_IN_CHECK:PIECE_PINNED;
587 } else {
588 threat = &(threats[i]);
589 }
590 }
591 }
592 }
594 // can't threaten specified position
595 if (!threat) {
596 return reason;
597 }
599 memcpy(move, threat, sizeof(Move));
600 return VALID_MOVE_SYNTAX;
601 } else {
602 return INVALID_POSITION;
603 }
604 }
606 int eval_move(GameState *gamestate, char *mstr, Move *move, uint8_t color) {
607 memset(move, 0, sizeof(Move));
608 move->fromfile = POS_UNSPECIFIED;
609 move->fromrow = POS_UNSPECIFIED;
611 size_t len = strlen(mstr);
612 if (len < 1 || len > 6) {
613 return INVALID_MOVE_SYNTAX;
614 }
616 /* evaluate check/checkmate flags */
617 if (mstr[len-1] == '+') {
618 len--; mstr[len] = '\0';
619 move->check = 1;
620 } else if (mstr[len-1] == '#') {
621 len--; mstr[len] = '\0';
622 /* ignore - validation should set game state */
623 }
625 /* evaluate promotion */
626 if (len > 3 && mstr[len-2] == '=') {
627 move->promotion = getpiece(mstr[len-1]);
628 if (!move->promotion) {
629 return INVALID_MOVE_SYNTAX;
630 } else {
631 move->promotion |= color;
632 len -= 2;
633 mstr[len] = 0;
634 }
635 }
637 if (len == 2) {
638 /* pawn move (e.g. "e4") */
639 move->piece = PAWN;
640 move->tofile = fileidx(mstr[0]);
641 move->torow = rowidx(mstr[1]);
642 } else if (len == 3) {
643 if (strcmp(mstr, "O-O") == 0) {
644 /* king side castling */
645 move->piece = KING;
646 move->fromfile = fileidx('e');
647 move->tofile = fileidx('g');
648 move->fromrow = move->torow = color == WHITE ? 0 : 7;
649 } else {
650 /* move (e.g. "Nf3") */
651 move->piece = getpiece(mstr[0]);
652 move->tofile = fileidx(mstr[1]);
653 move->torow = rowidx(mstr[2]);
654 }
655 } else if (len == 4) {
656 move->piece = getpiece(mstr[0]);
657 if (!move->piece) {
658 move->piece = PAWN;
659 move->fromfile = fileidx(mstr[0]);
660 }
661 if (mstr[1] == 'x') {
662 /* capture (e.g. "Nxf3", "dxe5") */
663 move->capture = 1;
664 } else {
665 /* move (e.g. "Ndf3", "N2c3", "e2e4") */
666 if (isfile(mstr[1])) {
667 move->fromfile = fileidx(mstr[1]);
668 if (move->piece == PAWN) {
669 move->piece = 0;
670 }
671 } else {
672 move->fromrow = rowidx(mstr[1]);
673 }
674 }
675 move->tofile = fileidx(mstr[2]);
676 move->torow = rowidx(mstr[3]);
677 } else if (len == 5) {
678 if (strcmp(mstr, "O-O-O") == 0) {
679 /* queen side castling "O-O-O" */
680 move->piece = KING;
681 move->fromfile = fileidx('e');
682 move->tofile = fileidx('c');
683 move->fromrow = move->torow = color == WHITE ? 0 : 7;
684 } else {
685 move->piece = getpiece(mstr[0]);
686 if (mstr[2] == 'x') {
687 move->capture = 1;
688 if (move->piece) {
689 /* capture (e.g. "Ndxf3") */
690 move->fromfile = fileidx(mstr[1]);
691 } else {
692 /* long notation capture (e.g. "e5xf6") */
693 move->piece = PAWN;
694 move->fromfile = fileidx(mstr[0]);
695 move->fromrow = rowidx(mstr[1]);
696 }
697 } else {
698 /* long notation move (e.g. "Nc5a4") */
699 move->fromfile = fileidx(mstr[1]);
700 move->fromrow = rowidx(mstr[2]);
701 }
702 move->tofile = fileidx(mstr[3]);
703 move->torow = rowidx(mstr[4]);
704 }
705 } else if (len == 6) {
706 /* long notation capture (e.g. "Nc5xf3") */
707 if (mstr[3] == 'x') {
708 move->capture = 1;
709 move->piece = getpiece(mstr[0]);
710 move->fromfile = fileidx(mstr[1]);
711 move->fromrow = rowidx(mstr[2]);
712 move->tofile = fileidx(mstr[4]);
713 move->torow = rowidx(mstr[5]);
714 }
715 }
718 if (move->piece) {
719 if (move->piece == PAWN
720 && move->torow == (color==WHITE?7:0)
721 && !move->promotion) {
722 return NEED_PROMOTION;
723 }
725 move->piece |= color;
726 if (move->fromfile == POS_UNSPECIFIED
727 || move->fromrow == POS_UNSPECIFIED) {
728 return getlocation(gamestate, move);
729 } else {
730 return chkidx(move) ? VALID_MOVE_SYNTAX : INVALID_POSITION;
731 }
732 } else {
733 return INVALID_MOVE_SYNTAX;
734 }
735 }
737 _Bool is_protected(GameState *gamestate, uint8_t row, uint8_t file,
738 uint8_t color) {
740 Move threats[16];
741 uint8_t threatcount;
742 if (get_real_threats(gamestate, row, file, color, threats, &threatcount)) {
743 for (int i = 0 ; i < threatcount ; i++) {
744 if (threats[i].piece != (color|KING)) {
745 return 1;
746 }
747 }
748 return 0;
749 } else {
750 return 0;
751 }
752 }
754 uint16_t remaining_movetime(GameInfo *gameinfo, GameState *gamestate,
755 uint8_t color) {
756 if (!gameinfo->timecontrol) {
757 return 0;
758 }
760 if (gamestate->movelist) {
761 uint16_t time = gameinfo->time;
762 suseconds_t micros = 0;
764 MoveList *movelist = color == WHITE ?
765 gamestate->movelist : gamestate->movelist->next;
767 while (movelist) {
768 time += gameinfo->addtime;
770 struct movetimeval *movetime = &(movelist->move.movetime);
771 if (movetime->tv_sec >= time) {
772 return 0;
773 }
775 time -= movetime->tv_sec;
776 micros += movetime->tv_usec;
778 movelist = movelist->next ? movelist->next->next : NULL;
779 }
781 time_t sec;
782 movelist = gamestate->lastmove;
783 if ((movelist->move.piece & COLOR_MASK) != color) {
784 struct movetimeval *lastmovetstamp = &(movelist->move.timestamp);
785 struct timeval currenttstamp;
786 gettimeofday(¤ttstamp, NULL);
787 micros += currenttstamp.tv_usec - lastmovetstamp->tv_usec;
788 sec = currenttstamp.tv_sec - lastmovetstamp->tv_sec;
789 if (sec >= time) {
790 return 0;
791 }
793 time -= sec;
794 }
796 sec = micros / 1e6L;
798 if (sec >= time) {
799 return 0;
800 }
802 time -= sec;
804 return time;
805 } else {
806 return gameinfo->time;
807 }
808 }
