2 * moves.c - Move generation and checking
4 * Copyright 1991 by Digital Equipment Corporation, Maynard,
7 * Enhancements Copyright 1992-2001, 2002, 2003, 2004, 2005, 2006,
8 * 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
10 * Enhancements Copyright 2005 Alessandro Scotti
12 * The following terms apply to Digital Equipment Corporation's copyright
14 * ------------------------------------------------------------------------
17 * Permission to use, copy, modify, and distribute this software and its
18 * documentation for any purpose and without fee is hereby granted,
19 * provided that the above copyright notice appear in all copies and that
20 * both that copyright notice and this permission notice appear in
21 * supporting documentation, and that the name of Digital not be
22 * used in advertising or publicity pertaining to distribution of the
23 * software without specific, written prior permission.
25 * DIGITAL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING
26 * ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL
27 * DIGITAL BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR
28 * ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
29 * WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
30 * ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
32 * ------------------------------------------------------------------------
34 * The following terms apply to the enhanced version of XBoard
35 * distributed by the Free Software Foundation:
36 * ------------------------------------------------------------------------
38 * GNU XBoard is free software: you can redistribute it and/or modify
39 * it under the terms of the GNU General Public License as published by
40 * the Free Software Foundation, either version 3 of the License, or (at
41 * your option) any later version.
43 * GNU XBoard is distributed in the hope that it will be useful, but
44 * WITHOUT ANY WARRANTY; without even the implied warranty of
45 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
46 * General Public License for more details.
48 * You should have received a copy of the GNU General Public License
49 * along with this program. If not, see http://www.gnu.org/licenses/. *
51 *------------------------------------------------------------------------
52 ** See the file ChangeLog for a revision history. */
59 #else /* not HAVE_STRING_H */
61 #endif /* not HAVE_STRING_H */
67 int WhitePiece P((ChessSquare));
68 int BlackPiece P((ChessSquare));
69 int SameColor P((ChessSquare, ChessSquare));
70 int PosFlags(int index);
72 extern signed char initialRights[BOARD_FILES]; /* [HGM] all rights enabled, set in InitPosition */
78 return (int) piece >= (int) WhitePawn && (int) piece < (int) BlackPawn;
84 return (int) piece >= (int) BlackPawn && (int) piece < (int) EmptySquare;
87 int SameColor(piece1, piece2)
88 ChessSquare piece1, piece2;
90 return ((int) piece1 >= (int) WhitePawn && /* [HGM] can be > King ! */
91 (int) piece1 < (int) BlackPawn &&
92 (int) piece2 >= (int) WhitePawn &&
93 (int) piece2 < (int) BlackPawn)
94 || ((int) piece1 >= (int) BlackPawn &&
95 (int) piece1 < (int) EmptySquare &&
96 (int) piece2 >= (int) BlackPawn &&
97 (int) piece2 < (int) EmptySquare);
100 ChessSquare PromoPiece(moveType)
106 case WhitePromotionQueen:
108 case BlackPromotionQueen:
110 case WhitePromotionRook:
112 case BlackPromotionRook:
114 case WhitePromotionBishop:
116 case BlackPromotionBishop:
118 case WhitePromotionKnight:
120 case BlackPromotionKnight:
122 case WhitePromotionKing:
124 case BlackPromotionKing:
126 case WhitePromotionChancellor:
127 return WhiteMarshall;
128 case BlackPromotionChancellor:
129 return BlackMarshall;
130 case WhitePromotionArchbishop:
132 case BlackPromotionArchbishop:
134 case WhitePromotionCentaur:
136 case BlackPromotionCentaur:
141 char pieceToChar[] = {
142 'P', 'N', 'B', 'R', 'Q', 'F', 'E', 'A', 'C', 'W', 'M',
143 'O', 'H', 'I', 'J', 'G', 'D', 'V', 'L', 'S', 'U', 'K',
144 'p', 'n', 'b', 'r', 'q', 'f', 'e', 'a', 'c', 'w', 'm',
145 'o', 'h', 'i', 'j', 'g', 'd', 'v', 'l', 's', 'u', 'k',
147 char pieceNickName[EmptySquare];
152 if((int)p < 0 || (int)p >= (int)EmptySquare) return('x'); /* [HGM] for safety */
153 return pieceToChar[(int) p];
156 int PieceToNumber(p) /* [HGM] holdings: count piece type, ignoring non-participating piece types */
160 ChessSquare start = (int)p >= (int)BlackPawn ? BlackPawn : WhitePawn;
162 while(start++ != p) if(pieceToChar[(int)start-1] != '.') i++;
166 ChessSquare CharToPiece(c)
170 for(i=0; i< (int) EmptySquare; i++)
171 if(pieceNickName[i] == c) return (ChessSquare) i;
172 for(i=0; i< (int) EmptySquare; i++)
173 if(pieceToChar[i] == c) return (ChessSquare) i;
177 ChessMove PromoCharToMoveType(whiteOnMove, promoChar)
180 { /* [HGM] made dependent on CharToPiece to alow alternate piece letters */
181 ChessSquare piece = CharToPiece(whiteOnMove ? ToUpper(promoChar) : ToLower(promoChar) );
184 if(promoChar == NULLCHAR) return NormalMove;
188 return WhitePromotionQueen;
190 return WhitePromotionRook;
192 return WhitePromotionBishop;
194 return WhitePromotionKnight;
196 return WhitePromotionKing;
198 return WhitePromotionArchbishop;
200 return WhitePromotionChancellor;
202 return WhitePromotionCentaur;
204 return BlackPromotionQueen;
206 return BlackPromotionRook;
208 return BlackPromotionBishop;
210 return BlackPromotionKnight;
212 return BlackPromotionKing;
214 return BlackPromotionArchbishop;
216 return BlackPromotionChancellor;
218 return BlackPromotionCentaur;
220 // not all promotion implemented yet! Take Queen for those we don't know.
221 return (whiteOnMove ? WhitePromotionQueen : BlackPromotionQueen);
225 void CopyBoard(to, from)
230 for (i = 0; i < BOARD_HEIGHT; i++)
231 for (j = 0; j < BOARD_WIDTH; j++)
232 to[i][j] = from[i][j];
233 for (j = 0; j < BOARD_FILES-1; j++) // [HGM] gamestate: copy castling rights and ep status
234 to[CASTLING][j] = from[CASTLING][j];
235 to[HOLDINGS_SET] = 0; // flag used in ICS play
238 int CompareBoards(board1, board2)
239 Board board1, board2;
243 for (i = 0; i < BOARD_HEIGHT; i++)
244 for (j = 0; j < BOARD_WIDTH; j++) {
245 if (board1[i][j] != board2[i][j])
252 /* Call callback once for each pseudo-legal move in the given
253 position, except castling moves. A move is pseudo-legal if it is
254 legal, or if it would be legal except that it leaves the king in
255 check. In the arguments, epfile is EP_NONE if the previous move
256 was not a double pawn push, or the file 0..7 if it was, or
257 EP_UNKNOWN if we don't know and want to allow all e.p. captures.
258 Promotion moves generated are to Queen only.
260 void GenPseudoLegal(board, flags, callback, closure)
263 MoveCallback callback;
267 int i, j, d, s, fs, rs, rt, ft, m;
268 int epfile = (signed char)board[EP_STATUS]; // [HGM] gamestate: extract ep status from board
269 int promoRank = gameInfo.variant == VariantMakruk ? 3 : 1;
271 for (rf = 0; rf < BOARD_HEIGHT; rf++)
272 for (ff = BOARD_LEFT; ff < BOARD_RGHT; ff++) {
275 if (flags & F_WHITE_ON_MOVE) {
276 if (!WhitePiece(board[rf][ff])) continue;
278 if (!BlackPiece(board[rf][ff])) continue;
280 m = 0; piece = board[rf][ff];
281 if(PieceToChar(piece) == '~')
282 piece = (ChessSquare) ( DEMOTED piece );
283 if(gameInfo.variant == VariantShogi)
284 piece = (ChessSquare) ( SHOGI piece );
287 /* case EmptySquare: [HGM] this is nonsense, and conflicts with Shogi cases */
289 /* can't happen ([HGM] except for faries...) */
293 if(gameInfo.variant == VariantXiangqi) {
294 /* [HGM] capture and move straight ahead in Xiangqi */
295 if (rf < BOARD_HEIGHT-1 &&
296 !SameColor(board[rf][ff], board[rf + 1][ff]) ) {
297 callback(board, flags, NormalMove,
298 rf, ff, rf + 1, ff, closure);
300 /* and move sideways when across the river */
301 for (s = -1; s <= 1; s += 2) {
302 if (rf >= BOARD_HEIGHT>>1 &&
303 ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
304 !WhitePiece(board[rf][ff+s]) ) {
305 callback(board, flags, NormalMove,
306 rf, ff, rf, ff+s, closure);
311 if (rf < BOARD_HEIGHT-1 && board[rf + 1][ff] == EmptySquare) {
312 callback(board, flags,
313 rf >= BOARD_HEIGHT-1-promoRank ? WhitePromotionQueen : NormalMove,
314 rf, ff, rf + 1, ff, closure);
316 if (rf == 1 && board[2][ff] == EmptySquare &&
317 gameInfo.variant != VariantShatranj && /* [HGM] */
318 gameInfo.variant != VariantCourier && /* [HGM] */
319 board[3][ff] == EmptySquare ) {
320 callback(board, flags, NormalMove,
321 rf, ff, 3, ff, closure);
323 for (s = -1; s <= 1; s += 2) {
324 if (rf < BOARD_HEIGHT-1 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
325 ((flags & F_KRIEGSPIEL_CAPTURE) ||
326 BlackPiece(board[rf + 1][ff + s]))) {
327 callback(board, flags,
328 rf >= BOARD_HEIGHT-1-promoRank ? WhitePromotionQueen : NormalMove,
329 rf, ff, rf + 1, ff + s, closure);
331 if (rf == BOARD_HEIGHT-4) {
332 if (ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
333 (epfile == ff + s || epfile == EP_UNKNOWN) &&
334 board[BOARD_HEIGHT-4][ff + s] == BlackPawn &&
335 board[BOARD_HEIGHT-3][ff + s] == EmptySquare) {
336 callback(board, flags, WhiteCapturesEnPassant,
337 rf, ff, 5, ff + s, closure);
344 if(gameInfo.variant == VariantXiangqi) {
345 /* [HGM] capture straight ahead in Xiangqi */
346 if (rf > 0 && !SameColor(board[rf][ff], board[rf - 1][ff]) ) {
347 callback(board, flags, NormalMove,
348 rf, ff, rf - 1, ff, closure);
350 /* and move sideways when across the river */
351 for (s = -1; s <= 1; s += 2) {
352 if (rf < BOARD_HEIGHT>>1 &&
353 ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
354 !BlackPiece(board[rf][ff+s]) ) {
355 callback(board, flags, NormalMove,
356 rf, ff, rf, ff+s, closure);
361 if (rf > 0 && board[rf - 1][ff] == EmptySquare) {
362 callback(board, flags,
363 rf <= promoRank ? BlackPromotionQueen : NormalMove,
364 rf, ff, rf - 1, ff, closure);
366 if (rf == BOARD_HEIGHT-2 && board[BOARD_HEIGHT-3][ff] == EmptySquare &&
367 gameInfo.variant != VariantShatranj && /* [HGM] */
368 gameInfo.variant != VariantCourier && /* [HGM] */
369 board[BOARD_HEIGHT-4][ff] == EmptySquare) {
370 callback(board, flags, NormalMove,
371 rf, ff, BOARD_HEIGHT-4, ff, closure);
373 for (s = -1; s <= 1; s += 2) {
374 if (rf > 0 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
375 ((flags & F_KRIEGSPIEL_CAPTURE) ||
376 WhitePiece(board[rf - 1][ff + s]))) {
377 callback(board, flags,
378 rf <= promoRank ? BlackPromotionQueen : NormalMove,
379 rf, ff, rf - 1, ff + s, closure);
382 if (ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
383 (epfile == ff + s || epfile == EP_UNKNOWN) &&
384 board[3][ff + s] == WhitePawn &&
385 board[2][ff + s] == EmptySquare) {
386 callback(board, flags, BlackCapturesEnPassant,
387 rf, ff, 2, ff + s, closure);
398 for (i = -1; i <= 1; i += 2)
399 for (j = -1; j <= 1; j += 2)
400 for (s = 1; s <= 2; s++) {
403 if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
404 && ( gameInfo.variant != VariantXiangqi || board[rf+i*(s-1)][ff+j*(2-s)] == EmptySquare)
405 && !SameColor(board[rf][ff], board[rt][ft]))
406 callback(board, flags, NormalMove,
407 rf, ff, rt, ft, closure);
411 case SHOGI WhiteKnight:
412 for (s = -1; s <= 1; s += 2) {
413 if (rf < BOARD_HEIGHT-2 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
414 !SameColor(board[rf][ff], board[rf + 2][ff + s])) {
415 callback(board, flags, NormalMove,
416 rf, ff, rf + 2, ff + s, closure);
421 case SHOGI BlackKnight:
422 for (s = -1; s <= 1; s += 2) {
423 if (rf > 1 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
424 !SameColor(board[rf][ff], board[rf - 2][ff + s])) {
425 callback(board, flags, NormalMove,
426 rf, ff, rf - 2, ff + s, closure);
433 for (d = 0; d <= 1; d++)
434 for (s = -1; s <= 1; s += 2) {
437 rt = rf + (i * s) * d;
438 ft = ff + (i * s) * (1 - d);
439 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
440 if (m == 0 && board[rt][ft] == EmptySquare)
441 callback(board, flags, NormalMove,
442 rf, ff, rt, ft, closure);
443 if (m == 1 && board[rt][ft] != EmptySquare &&
444 !SameColor(board[rf][ff], board[rt][ft]) )
445 callback(board, flags, NormalMove,
446 rf, ff, rt, ft, closure);
447 if (board[rt][ft] != EmptySquare && m++) break;
452 /* Gold General (and all its promoted versions) . First do the */
453 /* diagonal forward steps, then proceed as normal Wazir */
454 case SHOGI WhiteWazir:
455 case SHOGI (PROMOTED WhitePawn):
456 case SHOGI (PROMOTED WhiteKnight):
457 case SHOGI (PROMOTED WhiteQueen):
458 case SHOGI (PROMOTED WhiteFerz):
459 for (s = -1; s <= 1; s += 2) {
460 if (rf < BOARD_HEIGHT-1 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
461 !SameColor(board[rf][ff], board[rf + 1][ff + s])) {
462 callback(board, flags, NormalMove,
463 rf, ff, rf + 1, ff + s, closure);
468 case SHOGI BlackWazir:
469 case SHOGI (PROMOTED BlackPawn):
470 case SHOGI (PROMOTED BlackKnight):
471 case SHOGI (PROMOTED BlackQueen):
472 case SHOGI (PROMOTED BlackFerz):
473 for (s = -1; s <= 1; s += 2) {
474 if (rf > 0 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
475 !SameColor(board[rf][ff], board[rf - 1][ff + s])) {
476 callback(board, flags, NormalMove,
477 rf, ff, rf - 1, ff + s, closure);
484 for (d = 0; d <= 1; d++)
485 for (s = -1; s <= 1; s += 2) {
487 ft = ff + s * (1 - d);
488 if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
489 && !SameColor(board[rf][ff], board[rt][ft]) &&
490 (gameInfo.variant != VariantXiangqi || InPalace(rt, ft) ) )
491 callback(board, flags, NormalMove,
492 rf, ff, rt, ft, closure);
498 /* [HGM] support Shatranj pieces */
499 for (rs = -1; rs <= 1; rs += 2)
500 for (fs = -1; fs <= 1; fs += 2) {
503 if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
504 && ( gameInfo.variant != VariantXiangqi ||
505 board[rf+rs][ff+fs] == EmptySquare && (2*rf < BOARD_HEIGHT) == (2*rt < BOARD_HEIGHT) )
507 && !SameColor(board[rf][ff], board[rt][ft]))
508 callback(board, flags, NormalMove,
509 rf, ff, rt, ft, closure);
513 /* Shogi Dragon Horse has to continue with Wazir after Bishop */
514 case SHOGI WhiteCardinal:
515 case SHOGI BlackCardinal:
518 /* Capablanca Archbishop continues as Knight */
523 /* Shogi Bishops are ordinary Bishops */
524 case SHOGI WhiteBishop:
525 case SHOGI BlackBishop:
528 for (rs = -1; rs <= 1; rs += 2)
529 for (fs = -1; fs <= 1; fs += 2)
533 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
534 if (SameColor(board[rf][ff], board[rt][ft])) break;
535 callback(board, flags, NormalMove,
536 rf, ff, rt, ft, closure);
537 if (board[rt][ft] != EmptySquare) break;
539 if(m==1) goto mounted;
540 if(m==2) goto finishGold;
541 /* Bishop falls through */
544 /* Shogi Lance is unlike anything, and asymmetric at that */
545 case SHOGI WhiteQueen:
549 if (rt >= BOARD_HEIGHT) break;
550 if (SameColor(board[rf][ff], board[rt][ft])) break;
551 callback(board, flags, NormalMove,
552 rf, ff, rt, ft, closure);
553 if (board[rt][ft] != EmptySquare) break;
557 case SHOGI BlackQueen:
562 if (SameColor(board[rf][ff], board[rt][ft])) break;
563 callback(board, flags, NormalMove,
564 rf, ff, rt, ft, closure);
565 if (board[rt][ft] != EmptySquare) break;
569 /* Shogi Dragon King has to continue as Ferz after Rook moves */
570 case SHOGI WhiteDragon:
571 case SHOGI BlackDragon:
574 /* Capablanca Chancellor sets flag to continue as Knight */
579 /* Shogi Rooks are ordinary Rooks */
580 case SHOGI WhiteRook:
581 case SHOGI BlackRook:
584 for (d = 0; d <= 1; d++)
585 for (s = -1; s <= 1; s += 2)
587 rt = rf + (i * s) * d;
588 ft = ff + (i * s) * (1 - d);
589 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
590 if (SameColor(board[rf][ff], board[rt][ft])) break;
591 callback(board, flags, NormalMove,
592 rf, ff, rt, ft, closure);
593 if (board[rt][ft] != EmptySquare) break;
595 if(m==1) goto mounted;
596 if(m==2) goto finishSilver;
601 for (rs = -1; rs <= 1; rs++)
602 for (fs = -1; fs <= 1; fs++) {
603 if (rs == 0 && fs == 0) continue;
607 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
608 if (SameColor(board[rf][ff], board[rt][ft])) break;
609 callback(board, flags, NormalMove,
610 rf, ff, rt, ft, closure);
611 if (board[rt][ft] != EmptySquare) break;
616 /* Shogi Pawn and Silver General: first the Pawn move, */
617 /* then the General continues like a Ferz */
619 if(gameInfo.variant != VariantMakruk) goto commoner;
620 case SHOGI WhitePawn:
621 case SHOGI WhiteFerz:
622 if (rf < BOARD_HEIGHT-1 &&
623 !SameColor(board[rf][ff], board[rf + 1][ff]) )
624 callback(board, flags, NormalMove,
625 rf, ff, rf + 1, ff, closure);
626 if(piece != SHOGI WhitePawn) goto finishSilver;
630 if(gameInfo.variant != VariantMakruk) goto commoner;
631 case SHOGI BlackPawn:
632 case SHOGI BlackFerz:
634 !SameColor(board[rf][ff], board[rf - 1][ff]) )
635 callback(board, flags, NormalMove,
636 rf, ff, rf - 1, ff, closure);
637 if(piece == SHOGI BlackPawn) break;
642 /* [HGM] support Shatranj pieces */
643 for (rs = -1; rs <= 1; rs += 2)
644 for (fs = -1; fs <= 1; fs += 2) {
647 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) continue;
648 if (!SameColor(board[rf][ff], board[rt][ft]) &&
649 (gameInfo.variant != VariantXiangqi || InPalace(rt, ft) ) )
650 callback(board, flags, NormalMove,
651 rf, ff, rt, ft, closure);
657 m++; // [HGM] superchess: use for Centaur
659 case SHOGI WhiteKing:
660 case SHOGI BlackKing:
664 for (i = -1; i <= 1; i++)
665 for (j = -1; j <= 1; j++) {
666 if (i == 0 && j == 0) continue;
669 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) continue;
670 if (SameColor(board[rf][ff], board[rt][ft])) continue;
671 callback(board, flags, NormalMove,
672 rf, ff, rt, ft, closure);
674 if(m==1) goto mounted;
677 case WhiteNightrider:
678 case BlackNightrider:
679 for (i = -1; i <= 1; i += 2)
680 for (j = -1; j <= 1; j += 2)
681 for (s = 1; s <= 2; s++) { int k;
685 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
686 if (SameColor(board[rf][ff], board[rt][ft])) break;
687 callback(board, flags, NormalMove,
688 rf, ff, rt, ft, closure);
689 if (board[rt][ft] != EmptySquare) break;
693 case WhiteFalcon: // [HGM] wild: for wildcards, self-capture symbolizes move to anywhere
699 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
712 extern void GenLegalCallback P((Board board, int flags, ChessMove kind,
713 int rf, int ff, int rt, int ft,
716 void GenLegalCallback(board, flags, kind, rf, ff, rt, ft, closure)
723 register GenLegalClosure *cl = (GenLegalClosure *) closure;
725 if (!(flags & F_IGNORE_CHECK) &&
726 CheckTest(board, flags, rf, ff, rt, ft,
727 kind == WhiteCapturesEnPassant ||
728 kind == BlackCapturesEnPassant)) return;
729 if (flags & F_ATOMIC_CAPTURE) {
730 if (board[rt][ft] != EmptySquare ||
731 kind == WhiteCapturesEnPassant || kind == BlackCapturesEnPassant) {
733 ChessSquare king = (flags & F_WHITE_ON_MOVE) ? WhiteKing : BlackKing;
734 if (board[rf][ff] == king) return;
735 for (r = rt-1; r <= rt+1; r++) {
736 for (f = ft-1; f <= ft+1; f++) {
737 if (r >= 0 && r < BOARD_HEIGHT && f >= BOARD_LEFT && f < BOARD_RGHT &&
738 board[r][f] == king) return;
743 cl->cb(board, flags, kind, rf, ff, rt, ft, cl->cl);
750 int captures; // [HGM] losers
751 } LegalityTestClosure;
754 /* Like GenPseudoLegal, but (1) include castling moves, (2) unless
755 F_IGNORE_CHECK is set in the flags, omit moves that would leave the
756 king in check, and (3) if F_ATOMIC_CAPTURE is set in the flags, omit
757 moves that would destroy your own king. The CASTLE_OK flags are
758 true if castling is not yet ruled out by a move of the king or
759 rook. Return TRUE if the player on move is currently in check and
760 F_IGNORE_CHECK is not set. [HGM] add castlingRights parameter */
761 int GenLegal(board, flags, callback, closure)
764 MoveCallback callback;
768 int ff, ft, k, left, right;
769 int ignoreCheck = (flags & F_IGNORE_CHECK) != 0;
770 ChessSquare wKing = WhiteKing, bKing = BlackKing, *castlingRights = board[CASTLING];
774 GenPseudoLegal(board, flags, GenLegalCallback, (VOIDSTAR) &cl);
777 CheckTest(board, flags, -1, -1, -1, -1, FALSE)) return TRUE;
779 /* Generate castling moves */
780 if(gameInfo.variant == VariantKnightmate) { /* [HGM] Knightmate */
781 wKing = WhiteUnicorn; bKing = BlackUnicorn;
784 for (ff = BOARD_WIDTH>>1; ff >= (BOARD_WIDTH-1)>>1; ff-- /*ics wild 1*/) {
785 if ((flags & F_WHITE_ON_MOVE) &&
786 (flags & F_WHITE_KCASTLE_OK) &&
787 board[0][ff] == wKing &&
788 board[0][ff + 1] == EmptySquare &&
789 board[0][ff + 2] == EmptySquare &&
790 board[0][BOARD_RGHT-3] == EmptySquare &&
791 board[0][BOARD_RGHT-2] == EmptySquare &&
792 board[0][BOARD_RGHT-1] == WhiteRook &&
793 castlingRights[0] != NoRights && /* [HGM] check rights */
794 ( castlingRights[2] == ff || castlingRights[6] == ff ) &&
796 (!CheckTest(board, flags, 0, ff, 0, ff + 1, FALSE) &&
797 !CheckTest(board, flags, 0, ff, 0, BOARD_RGHT-3, FALSE) &&
798 (gameInfo.variant != VariantJanus || !CheckTest(board, flags, 0, ff, 0, BOARD_RGHT-2, FALSE)) &&
799 !CheckTest(board, flags, 0, ff, 0, ff + 2, FALSE)))) {
801 callback(board, flags,
802 ff==BOARD_WIDTH>>1 ? WhiteKingSideCastle : WhiteKingSideCastleWild,
803 0, ff, 0, ff + ((gameInfo.boardWidth+2)>>2) + (gameInfo.variant == VariantJanus), closure);
805 if ((flags & F_WHITE_ON_MOVE) &&
806 (flags & F_WHITE_QCASTLE_OK) &&
807 board[0][ff] == wKing &&
808 board[0][ff - 1] == EmptySquare &&
809 board[0][ff - 2] == EmptySquare &&
810 board[0][BOARD_LEFT+2] == EmptySquare &&
811 board[0][BOARD_LEFT+1] == EmptySquare &&
812 board[0][BOARD_LEFT+0] == WhiteRook &&
813 castlingRights[1] != NoRights && /* [HGM] check rights */
814 ( castlingRights[2] == ff || castlingRights[6] == ff ) &&
816 (!CheckTest(board, flags, 0, ff, 0, ff - 1, FALSE) &&
817 !CheckTest(board, flags, 0, ff, 0, BOARD_LEFT+3, FALSE) &&
818 !CheckTest(board, flags, 0, ff, 0, ff - 2, FALSE)))) {
820 callback(board, flags,
821 ff==BOARD_WIDTH>>1 ? WhiteQueenSideCastle : WhiteQueenSideCastleWild,
822 0, ff, 0, ff - ((gameInfo.boardWidth+2)>>2), closure);
824 if (!(flags & F_WHITE_ON_MOVE) &&
825 (flags & F_BLACK_KCASTLE_OK) &&
826 board[BOARD_HEIGHT-1][ff] == bKing &&
827 board[BOARD_HEIGHT-1][ff + 1] == EmptySquare &&
828 board[BOARD_HEIGHT-1][ff + 2] == EmptySquare &&
829 board[BOARD_HEIGHT-1][BOARD_RGHT-3] == EmptySquare &&
830 board[BOARD_HEIGHT-1][BOARD_RGHT-2] == EmptySquare &&
831 board[BOARD_HEIGHT-1][BOARD_RGHT-1] == BlackRook &&
832 castlingRights[3] != NoRights && /* [HGM] check rights */
833 ( castlingRights[5] == ff || castlingRights[7] == ff ) &&
835 (!CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff + 1, FALSE) &&
836 !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, BOARD_RGHT-3, FALSE) &&
837 (gameInfo.variant != VariantJanus || !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, BOARD_RGHT-2, FALSE)) &&
838 !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff + 2, FALSE)))) {
840 callback(board, flags,
841 ff==BOARD_WIDTH>>1 ? BlackKingSideCastle : BlackKingSideCastleWild,
842 BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff + ((gameInfo.boardWidth+2)>>2) + (gameInfo.variant == VariantJanus), closure);
844 if (!(flags & F_WHITE_ON_MOVE) &&
845 (flags & F_BLACK_QCASTLE_OK) &&
846 board[BOARD_HEIGHT-1][ff] == bKing &&
847 board[BOARD_HEIGHT-1][ff - 1] == EmptySquare &&
848 board[BOARD_HEIGHT-1][ff - 2] == EmptySquare &&
849 board[BOARD_HEIGHT-1][BOARD_LEFT+2] == EmptySquare &&
850 board[BOARD_HEIGHT-1][BOARD_LEFT+1] == EmptySquare &&
851 board[BOARD_HEIGHT-1][BOARD_LEFT+0] == BlackRook &&
852 castlingRights[4] != NoRights && /* [HGM] check rights */
853 ( castlingRights[5] == ff || castlingRights[7] == ff ) &&
855 (!CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff - 1, FALSE) &&
856 !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, BOARD_LEFT+3, FALSE) &&
857 !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff - 2, FALSE)))) {
859 callback(board, flags,
860 ff==BOARD_WIDTH>>1 ? BlackQueenSideCastle : BlackQueenSideCastleWild,
861 BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff - ((gameInfo.boardWidth+2)>>2), closure);
865 if(flags & F_FRC_TYPE_CASTLING) {
867 /* generate all potential FRC castling moves (KxR), ignoring flags */
868 /* [HGM] test if the Rooks we find have castling rights */
871 if ((flags & F_WHITE_ON_MOVE) != 0) {
872 ff = castlingRights[2]; /* King file if we have any rights */
873 if(ff != NoRights && board[0][ff] == WhiteKing) {
874 if (appData.debugMode) {
875 fprintf(debugFP, "FRC castling, %d %d %d %d %d %d\n",
876 castlingRights[0],castlingRights[1],ff,castlingRights[3],castlingRights[4],castlingRights[5]);
878 ft = castlingRights[0]; /* Rook file if we have H-side rights */
880 right = BOARD_RGHT-2;
881 if(ff == BOARD_RGHT-2) left = right = ff-1; /* special case */
882 for(k=left; k<=right && ft != NoRights; k++) /* first test if blocked */
883 if(k != ft && board[0][k] != EmptySquare) ft = NoRights;
884 for(k=left; k<right && ft != NoRights; k++) /* then if not checked */
885 if(!ignoreCheck && CheckTest(board, flags, 0, ff, 0, k, FALSE)) ft = NoRights;
886 if(ft != NoRights && board[0][ft] == WhiteRook)
887 callback(board, flags, WhiteHSideCastleFR, 0, ff, 0, ft, closure);
889 ft = castlingRights[1]; /* Rook file if we have A-side rights */
892 if(ff <= BOARD_LEFT+2) { left = ff+1; right = BOARD_LEFT+3; }
893 for(k=left; k<=right && ft != NoRights; k++) /* first test if blocked */
894 if(k != ft && board[0][k] != EmptySquare) ft = NoRights;
895 if(ff > BOARD_LEFT+2)
896 for(k=left+1; k<=right && ft != NoRights; k++) /* then if not checked */
897 if(!ignoreCheck && CheckTest(board, flags, 0, ff, 0, k, FALSE)) ft = NoRights;
898 if(ft != NoRights && board[0][ft] == WhiteRook)
899 callback(board, flags, WhiteASideCastleFR, 0, ff, 0, ft, closure);
902 ff = castlingRights[5]; /* King file if we have any rights */
903 if(ff != NoRights && board[BOARD_HEIGHT-1][ff] == BlackKing) {
904 ft = castlingRights[3]; /* Rook file if we have H-side rights */
906 right = BOARD_RGHT-2;
907 if(ff == BOARD_RGHT-2) left = right = ff-1; /* special case */
908 for(k=left; k<=right && ft != NoRights; k++) /* first test if blocked */
909 if(k != ft && board[BOARD_HEIGHT-1][k] != EmptySquare) ft = NoRights;
910 for(k=left; k<right && ft != NoRights; k++) /* then if not checked */
911 if(!ignoreCheck && CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, k, FALSE)) ft = NoRights;
912 if(ft != NoRights && board[BOARD_HEIGHT-1][ft] == BlackRook)
913 callback(board, flags, BlackHSideCastleFR, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ft, closure);
915 ft = castlingRights[4]; /* Rook file if we have A-side rights */
918 if(ff <= BOARD_LEFT+2) { left = ff+1; right = BOARD_LEFT+3; }
919 for(k=left; k<=right && ft != NoRights; k++) /* first test if blocked */
920 if(k != ft && board[BOARD_HEIGHT-1][k] != EmptySquare) ft = NoRights;
921 if(ff > BOARD_LEFT+2)
922 for(k=left+1; k<=right && ft != NoRights; k++) /* then if not checked */
923 if(!ignoreCheck && CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, k, FALSE)) ft = NoRights;
924 if(ft != NoRights && board[BOARD_HEIGHT-1][ft] == BlackRook)
925 callback(board, flags, BlackASideCastleFR, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ft, closure);
941 extern void CheckTestCallback P((Board board, int flags, ChessMove kind,
942 int rf, int ff, int rt, int ft,
946 void CheckTestCallback(board, flags, kind, rf, ff, rt, ft, closure)
953 register CheckTestClosure *cl = (CheckTestClosure *) closure;
955 if (rt == cl->rking && ft == cl->fking) cl->check++;
959 /* If the player on move were to move from (rf, ff) to (rt, ft), would
960 he leave himself in check? Or if rf == -1, is the player on move
961 in check now? enPassant must be TRUE if the indicated move is an
962 e.p. capture. The possibility of castling out of a check along the
963 back rank is not accounted for (i.e., we still return nonzero), as
964 this is illegal anyway. Return value is the number of times the
966 int CheckTest(board, flags, rf, ff, rt, ft, enPassant)
969 int rf, ff, rt, ft, enPassant;
972 ChessSquare king = flags & F_WHITE_ON_MOVE ? WhiteKing : BlackKing;
973 ChessSquare captured = EmptySquare;
974 /* Suppress warnings on uninitialized variables */
976 if(gameInfo.variant == VariantXiangqi)
977 king = flags & F_WHITE_ON_MOVE ? WhiteWazir : BlackWazir;
978 if(gameInfo.variant == VariantKnightmate)
979 king = flags & F_WHITE_ON_MOVE ? WhiteUnicorn : BlackUnicorn;
983 captured = board[rf][ft];
984 board[rf][ft] = EmptySquare;
986 captured = board[rt][ft];
988 board[rt][ft] = board[rf][ff];
989 board[rf][ff] = EmptySquare;
992 /* For compatibility with ICS wild 9, we scan the board in the
993 order a1, a2, a3, ... b1, b2, ..., h8 to find the first king,
994 and we test only whether that one is in check. */
996 for (cl.fking = BOARD_LEFT+0; cl.fking < BOARD_RGHT; cl.fking++)
997 for (cl.rking = 0; cl.rking < BOARD_HEIGHT; cl.rking++) {
998 if (board[cl.rking][cl.fking] == king) {
999 if(gameInfo.variant == VariantXiangqi) {
1000 /* [HGM] In Xiangqi opposing Kings means check as well */
1002 dir = (king >= BlackPawn) ? -1 : 1;
1003 for( i=cl.rking+dir; i>=0 && i<BOARD_HEIGHT &&
1004 board[i][cl.fking] == EmptySquare; i+=dir );
1005 if(i>=0 && i<BOARD_HEIGHT &&
1006 board[i][cl.fking] == (dir>0 ? BlackWazir : WhiteWazir) )
1010 GenPseudoLegal(board, flags ^ F_WHITE_ON_MOVE, CheckTestCallback, (VOIDSTAR) &cl);
1011 goto undo_move; /* 2-level break */
1018 board[rf][ff] = board[rt][ft];
1020 board[rf][ft] = captured;
1021 board[rt][ft] = EmptySquare;
1023 board[rt][ft] = captured;
1027 return cl.fking < BOARD_RGHT ? cl.check : 1000; // [HGM] atomic: return 1000 if we have no king
1031 extern void LegalityTestCallback P((Board board, int flags, ChessMove kind,
1032 int rf, int ff, int rt, int ft,
1035 void LegalityTestCallback(board, flags, kind, rf, ff, rt, ft, closure)
1042 register LegalityTestClosure *cl = (LegalityTestClosure *) closure;
1044 // if (appData.debugMode) {
1045 // fprintf(debugFP, "Legality test: %c%c%c%c\n", ff+AAA, rf+ONE, ft+AAA, rt+ONE);
1047 if(board[rt][ft] != EmptySquare || kind==WhiteCapturesEnPassant || kind==BlackCapturesEnPassant)
1048 cl->captures++; // [HGM] losers: count legal captures
1049 if (rf == cl->rf && ff == cl->ff && rt == cl->rt && ft == cl->ft)
1053 ChessMove LegalityTest(board, flags, rf, ff, rt, ft, promoChar)
1056 int rf, ff, rt, ft, promoChar;
1058 LegalityTestClosure cl; ChessSquare piece = board[rf][ff], *castlingRights = board[CASTLING];
1060 if (appData.debugMode) {
1062 for(i=0; i<6; i++) fprintf(debugFP, "%d ", castlingRights[i]);
1063 fprintf(debugFP, "Legality test? %c%c%c%c\n", ff+AAA, rf+ONE, ft+AAA, rt+ONE);
1065 /* [HGM] Lance, Cobra and Falcon are wildcard pieces; consider all their moves legal */
1066 /* (perhaps we should disallow moves that obviously leave us in check?) */
1067 if(piece == WhiteFalcon || piece == BlackFalcon ||
1068 piece == WhiteCobra || piece == BlackCobra ||
1069 piece == WhiteLance || piece == BlackLance)
1070 return CheckTest(board, flags, rf, ff, rt, ft, FALSE) ? IllegalMove : NormalMove;
1076 cl.kind = IllegalMove;
1077 cl.captures = 0; // [HGM] losers: prepare to count legal captures.
1078 GenLegal(board, flags, LegalityTestCallback, (VOIDSTAR) &cl);
1079 if((flags & F_MANDATORY_CAPTURE) && cl.captures && board[rt][ft] == EmptySquare
1080 && cl.kind != WhiteCapturesEnPassant && cl.kind != BlackCapturesEnPassant)
1081 return(IllegalMove); // [HGM] losers: if there are legal captures, non-capts are illegal
1083 if(gameInfo.variant == VariantShogi) {
1084 /* [HGM] Shogi promotions. '=' means defer */
1085 if(rf != DROP_RANK && cl.kind == NormalMove) {
1086 ChessSquare piece = board[rf][ff];
1088 if(promoChar == PieceToChar(BlackQueen)) promoChar = NULLCHAR; /* [HGM] Kludge */
1089 if(promoChar != NULLCHAR && promoChar != 'x' &&
1090 promoChar != '+' && promoChar != '=' &&
1091 ToUpper(PieceToChar(PROMOTED piece)) != ToUpper(promoChar) )
1092 cl.kind = IllegalMove;
1093 else if(flags & F_WHITE_ON_MOVE) {
1094 if( (int) piece < (int) WhiteWazir &&
1095 (rf > BOARD_HEIGHT-4 || rt > BOARD_HEIGHT-4) ) {
1096 if( (piece == WhitePawn || piece == WhiteQueen) && rt > BOARD_HEIGHT-2 ||
1097 piece == WhiteKnight && rt > BOARD_HEIGHT-3) /* promotion mandatory */
1098 cl.kind = promoChar == '=' ? IllegalMove : WhitePromotionKnight;
1099 else /* promotion optional, default is promote */
1100 cl.kind = promoChar == '=' ? NormalMove : WhitePromotionQueen;
1102 } else cl.kind = (promoChar == NULLCHAR || promoChar == 'x' || promoChar == '=') ?
1103 NormalMove : IllegalMove;
1105 if( (int) piece < (int) BlackWazir && (rf < 3 || rt < 3) ) {
1106 if( (piece == BlackPawn || piece == BlackQueen) && rt < 1 ||
1107 piece == BlackKnight && rt < 2 ) /* promotion obligatory */
1108 cl.kind = promoChar == '=' ? IllegalMove : BlackPromotionKnight;
1109 else /* promotion optional, default is promote */
1110 cl.kind = promoChar == '=' ? NormalMove : BlackPromotionQueen;
1112 } else cl.kind = (promoChar == NULLCHAR || promoChar == 'x' || promoChar == '=') ?
1113 NormalMove : IllegalMove;
1117 if (promoChar != NULLCHAR && promoChar != 'x') {
1118 if(promoChar == '=') cl.kind = IllegalMove; else // [HGM] shogi: no deferred promotion outside Shogi
1119 if (cl.kind == WhitePromotionQueen || cl.kind == BlackPromotionQueen) {
1121 PromoCharToMoveType((flags & F_WHITE_ON_MOVE) != 0, promoChar);
1123 cl.kind = IllegalMove;
1126 /* [HGM] For promotions, 'ToQueen' = optional, 'ToKnight' = mandatory */
1134 extern void MateTestCallback P((Board board, int flags, ChessMove kind,
1135 int rf, int ff, int rt, int ft,
1138 void MateTestCallback(board, flags, kind, rf, ff, rt, ft, closure)
1145 register MateTestClosure *cl = (MateTestClosure *) closure;
1150 /* Return MT_NONE, MT_CHECK, MT_CHECKMATE, or MT_STALEMATE */
1151 int MateTest(board, flags)
1156 int inCheck, r, f, myPieces=0, hisPieces=0, nrKing=0;
1157 ChessSquare king = flags & F_WHITE_ON_MOVE ? WhiteKing : BlackKing;
1159 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++) {
1160 // [HGM] losers: Count pieces and kings, to detect other unorthodox winning conditions
1161 nrKing += (board[r][f] == king); // stm has king
1162 if( board[r][f] != EmptySquare ) {
1163 if((int)board[r][f] <= (int)king && (int)board[r][f] >= (int)king - (int)WhiteKing + (int)WhitePawn)
1168 if(appData.debugMode) fprintf(debugFP, "MateTest: K=%d, my=%d, his=%d\n", nrKing, myPieces, hisPieces);
1169 switch(gameInfo.variant) { // [HGM] losers: extinction wins
1170 case VariantShatranj:
1171 if(hisPieces == 1) return myPieces > 1 ? MT_BARE : MT_DRAW;
1175 if(nrKing == 0) return MT_NOKING;
1178 if(myPieces == 1) return MT_BARE;
1181 inCheck = GenLegal(board, flags, MateTestCallback, (VOIDSTAR) &cl);
1182 // [HGM] 3check: yet to do!
1184 return inCheck ? MT_CHECK : MT_NONE;
1186 if(gameInfo.variant == VariantSuicide) // [HGM] losers: always stalemate, since no check, but result varies
1187 return myPieces == hisPieces ? MT_STALEMATE :
1188 myPieces > hisPieces ? MT_STAINMATE : MT_STEALMATE;
1189 else if(gameInfo.variant == VariantLosers) return inCheck ? MT_TRICKMATE : MT_STEALMATE;
1190 else if(gameInfo.variant == VariantGiveaway) return MT_STEALMATE; // no check exists, stalemated = win
1192 return inCheck ? MT_CHECKMATE
1193 : (gameInfo.variant == VariantXiangqi || gameInfo.variant == VariantShatranj) ?
1194 MT_STAINMATE : MT_STALEMATE;
1199 extern void DisambiguateCallback P((Board board, int flags, ChessMove kind,
1200 int rf, int ff, int rt, int ft,
1203 void DisambiguateCallback(board, flags, kind, rf, ff, rt, ft, closure)
1210 register DisambiguateClosure *cl = (DisambiguateClosure *) closure;
1211 int wildCard = FALSE; ChessSquare piece = board[rf][ff];
1213 // [HGM] wild: for wild-card pieces rt and rf are dummies
1214 if(piece == WhiteFalcon || piece == BlackFalcon ||
1215 piece == WhiteCobra || piece == BlackCobra ||
1216 piece == WhiteLance || piece == BlackLance)
1219 if ((cl->pieceIn == EmptySquare || cl->pieceIn == board[rf][ff]
1220 || PieceToChar(board[rf][ff]) == '~'
1221 && cl->pieceIn == (ChessSquare)(DEMOTED board[rf][ff])
1223 (cl->rfIn == -1 || cl->rfIn == rf) &&
1224 (cl->ffIn == -1 || cl->ffIn == ff) &&
1225 (cl->rtIn == -1 || cl->rtIn == rt || wildCard) &&
1226 (cl->ftIn == -1 || cl->ftIn == ft || wildCard)) {
1229 if(cl->count == 1 || board[rt][ft] != EmptySquare) {
1230 // [HGM] oneclick: if multiple moves, be sure we remember capture
1231 cl->piece = board[rf][ff];
1234 cl->rt = wildCard ? cl->rtIn : rt;
1235 cl->ft = wildCard ? cl->ftIn : ft;
1238 cl->captures += (board[cl->rt][cl->ft] != EmptySquare); // [HGM] oneclick: count captures
1242 void Disambiguate(board, flags, closure)
1245 DisambiguateClosure *closure;
1247 int illegal = 0; char c = closure->promoCharIn;
1249 closure->count = closure->captures = 0;
1250 closure->rf = closure->ff = closure->rt = closure->ft = 0;
1251 closure->kind = ImpossibleMove;
1252 if (appData.debugMode) {
1253 fprintf(debugFP, "Disambiguate in: %d(%d,%d)-(%d,%d) = %d (%c)\n",
1254 closure->pieceIn,closure->ffIn,closure->rfIn,closure->ftIn,closure->rtIn,
1255 closure->promoCharIn, closure->promoCharIn >= ' ' ? closure->promoCharIn : '-');
1257 GenLegal(board, flags, DisambiguateCallback, (VOIDSTAR) closure);
1258 if (closure->count == 0) {
1259 /* See if it's an illegal move due to check */
1261 GenLegal(board, flags|F_IGNORE_CHECK, DisambiguateCallback, (VOIDSTAR) closure);
1262 if (closure->count == 0) {
1263 /* No, it's not even that */
1264 if (appData.debugMode) { int i, j;
1265 for(i=BOARD_HEIGHT-1; i>=0; i--) {
1266 for(j=0; j<BOARD_WIDTH; j++)
1267 fprintf(debugFP, "%3d", (int) board[i][j]);
1268 fprintf(debugFP, "\n");
1275 if(gameInfo.variant == VariantShogi) {
1276 /* [HGM] Shogi promotions. '=' means defer */
1277 if(closure->rfIn != DROP_RANK && closure->kind == NormalMove) {
1278 ChessSquare piece = closure->piece;
1279 if(c != NULLCHAR && c != 'x' && c != '+' && c != '=' &&
1280 ToUpper(PieceToChar(PROMOTED piece)) != ToUpper(c) )
1281 closure->kind = IllegalMove;
1282 else if(flags & F_WHITE_ON_MOVE) {
1283 if( (int) piece < (int) WhiteWazir &&
1284 (closure->rf > BOARD_HEIGHT-4 || closure->rt > BOARD_HEIGHT-4) ) {
1285 if( (piece == WhitePawn || piece == WhiteQueen) && closure->rt > BOARD_HEIGHT-2 ||
1286 piece == WhiteKnight && closure->rt > BOARD_HEIGHT-3) /* promotion mandatory */
1287 closure->kind = c == '=' ? IllegalMove : WhitePromotionKnight;
1288 else /* promotion optional, default is promote */
1289 closure->kind = c == '=' ? NormalMove : WhitePromotionQueen;
1290 if(c != '=') closure->promoCharIn = 'q';
1291 } else closure->kind = (c == NULLCHAR || c == 'x' || c == '=') ?
1292 NormalMove : IllegalMove;
1294 if( (int) piece < (int) BlackWazir && (closure->rf < 3 || closure->rt < 3) ) {
1295 if( (piece == BlackPawn || piece == BlackQueen) && closure->rt < 1 ||
1296 piece == BlackKnight && closure->rt < 2 ) /* promotion obligatory */
1297 closure->kind = c == '=' ? IllegalMove : BlackPromotionKnight;
1298 else /* promotion optional, default is promote */
1299 closure->kind = c == '=' ? NormalMove : BlackPromotionQueen;
1300 if(c != '=') closure->promoCharIn = 'q';
1301 } else closure->kind = (c == NULLCHAR || c == 'x' || c == '=') ?
1302 NormalMove : IllegalMove;
1306 if (closure->promoCharIn != NULLCHAR && closure->promoCharIn != 'x') {
1307 if (closure->kind == WhitePromotionQueen
1308 || closure->kind == BlackPromotionQueen) {
1310 PromoCharToMoveType((flags & F_WHITE_ON_MOVE) != 0,
1311 closure->promoCharIn);
1313 closure->kind = IllegalMove;
1316 /* [HGM] returns 'q' for optional promotion, 'n' for mandatory */
1317 if(closure->promoCharIn != '=')
1318 closure->promoChar = ToLower(closure->promoCharIn);
1319 else closure->promoChar = '=';
1320 if (closure->promoChar == 'x') closure->promoChar = NULLCHAR;
1321 if (closure->count > 1) {
1322 closure->kind = AmbiguousMove;
1325 /* Note: If more than one illegal move matches, but no legal
1326 moves, we return IllegalMove, not AmbiguousMove. Caller
1327 can look at closure->count to detect this.
1329 closure->kind = IllegalMove;
1331 if(closure->kind == IllegalMove)
1332 /* [HGM] might be a variant we don't understand, pass on promotion info */
1333 closure->promoChar = ToLower(closure->promoCharIn);
1334 if (appData.debugMode) {
1335 fprintf(debugFP, "Disambiguate out: %d(%d,%d)-(%d,%d) = %d (%c)\n",
1336 closure->piece,closure->ff,closure->rf,closure->ft,closure->rt,closure->promoChar,
1337 closure->promoChar >= ' ' ? closure->promoChar:'-');
1351 } CoordsToAlgebraicClosure;
1353 extern void CoordsToAlgebraicCallback P((Board board, int flags,
1354 ChessMove kind, int rf, int ff,
1355 int rt, int ft, VOIDSTAR closure));
1357 void CoordsToAlgebraicCallback(board, flags, kind, rf, ff, rt, ft, closure)
1364 register CoordsToAlgebraicClosure *cl =
1365 (CoordsToAlgebraicClosure *) closure;
1367 if (rt == cl->rt && ft == cl->ft &&
1368 (board[rf][ff] == cl->piece
1369 || PieceToChar(board[rf][ff]) == '~' &&
1370 (ChessSquare) (DEMOTED board[rf][ff]) == cl->piece)
1374 cl->kind = kind; /* this is the move we want */
1376 cl->file++; /* need file to rule out this move */
1380 cl->rank++; /* need rank to rule out this move */
1382 cl->either++; /* rank or file will rule out this move */
1388 /* Convert coordinates to normal algebraic notation.
1389 promoChar must be NULLCHAR or 'x' if not a promotion.
1391 ChessMove CoordsToAlgebraic(board, flags, rf, ff, rt, ft, promoChar, out)
1400 char *outp = out, c;
1401 CoordsToAlgebraicClosure cl;
1403 if (rf == DROP_RANK) {
1404 /* Bughouse piece drop */
1405 *outp++ = ToUpper(PieceToChar((ChessSquare) ff));
1410 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
1412 return (flags & F_WHITE_ON_MOVE) ? WhiteDrop : BlackDrop;
1415 if (promoChar == 'x') promoChar = NULLCHAR;
1416 piece = board[rf][ff];
1417 if(PieceToChar(piece)=='~') piece = (ChessSquare)(DEMOTED piece);
1419 if (appData.debugMode)
1420 fprintf(debugFP, "CoordsToAlgebraic, piece=%d (%d,%d)-(%d,%d) %c\n", (int)piece,ff,rf,ft,rt,promoChar >= ' ' ? promoChar : '-');
1424 kind = LegalityTest(board, flags, rf, ff, rt, ft, promoChar);
1425 if (kind == IllegalMove && !(flags&F_IGNORE_CHECK)) {
1426 /* Keep short notation if move is illegal only because it
1427 leaves the player in check, but still return IllegalMove */
1428 kind = LegalityTest(board, flags|F_IGNORE_CHECK, rf, ff, rt, ft, promoChar);
1429 if (kind == IllegalMove) break;
1434 if (ff == ft && board[rt][ft] == EmptySquare) { /* [HGM] Xiangqi has straight noncapts! */
1435 /* Non-capture; use style "e5" */
1438 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
1440 /* Capture; use style "exd5" */
1441 if(gameInfo.variant != VariantXiangqi || board[rt][ft] != EmptySquare )
1442 *outp++ = 'x'; /* [HGM] Xiangqi has sideway noncaptures across river! */
1446 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
1448 /* Use promotion suffix style "=Q" */
1450 if (appData.debugMode)
1451 fprintf(debugFP, "movetype=%d, promochar=%d=%c\n", (int)kind, promoChar, promoChar >= ' ' ? promoChar : '-');
1452 if (promoChar != NULLCHAR) {
1453 if(gameInfo.variant == VariantShogi) {
1454 /* [HGM] ... but not in Shogi! */
1455 *outp++ = promoChar == '=' ? '=' : '+';
1458 *outp++ = ToUpper(promoChar);
1467 /* Fabien moved code: FRC castling first (if KxR), wild castling second */
1468 /* Code added by Tord: FRC castling. */
1469 if((piece == WhiteKing && board[rt][ft] == WhiteRook) ||
1470 (piece == BlackKing && board[rt][ft] == BlackRook)) {
1471 if(ft > ff) strcpy(out, "O-O"); else strcpy(out, "O-O-O");
1472 return LegalityTest(board, flags, rf, ff, rt, ft, promoChar);
1474 /* End of code added by Tord */
1475 /* Test for castling or ICS wild castling */
1476 /* Use style "O-O" (oh-oh) for PGN compatibility */
1477 else if (rf == rt &&
1478 rf == ((piece == WhiteKing) ? 0 : BOARD_HEIGHT-1) &&
1479 ((ff == BOARD_WIDTH>>1 && (ft == BOARD_LEFT+2 || ft == BOARD_RGHT-2)) ||
1480 (ff == (BOARD_WIDTH-1)>>1 && (ft == BOARD_LEFT+1 || ft == BOARD_RGHT-3)))) {
1481 if(ft==BOARD_LEFT+1 || ft==BOARD_RGHT-2)
1484 strcpy(out, "O-O-O");
1486 /* This notation is always unambiguous, unless there are
1487 kings on both the d and e files, with "wild castling"
1488 possible for the king on the d file and normal castling
1489 possible for the other. ICS rules for wild 9
1490 effectively make castling illegal for either king in
1491 this situation. So I am not going to worry about it;
1492 I'll just generate an ambiguous O-O in this case.
1494 return LegalityTest(board, flags, rf, ff, rt, ft, promoChar);
1497 /* else fall through */
1505 cl.kind = IllegalMove;
1506 cl.rank = cl.file = cl.either = 0;
1507 GenLegal(board, flags, CoordsToAlgebraicCallback, (VOIDSTAR) &cl);
1509 if (cl.kind == IllegalMove && !(flags&F_IGNORE_CHECK)) {
1510 /* Generate pretty moves for moving into check, but
1511 still return IllegalMove.
1513 GenLegal(board, flags|F_IGNORE_CHECK, CoordsToAlgebraicCallback, (VOIDSTAR) &cl);
1514 if (cl.kind == IllegalMove) break;
1515 cl.kind = IllegalMove;
1518 /* Style is "Nf3" or "Nxf7" if this is unambiguous,
1519 else "Ngf3" or "Ngxf7",
1520 else "N1f3" or "N5xf7",
1521 else "Ng1f3" or "Ng5xf7".
1523 c = PieceToChar(piece) ;
1524 if( c == '~' || c == '+') {
1525 /* [HGM] print nonexistent piece as its demoted version */
1526 piece = (ChessSquare) (DEMOTED piece);
1528 if(c=='+') *outp++ = c;
1529 *outp++ = ToUpper(PieceToChar(piece));
1531 if (cl.file || (cl.either && !cl.rank)) {
1537 else { *outp++ = (rf+ONE-'0')/10 + '0';*outp++ = (rf+ONE-'0')%10 + '0'; }
1540 if(board[rt][ft] != EmptySquare)
1546 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
1548 if (gameInfo.variant == VariantShogi) {
1549 /* [HGM] in Shogi non-pawns can promote */
1550 if(flags & F_WHITE_ON_MOVE) {
1551 if( (int) cl.piece < (int) WhiteWazir &&
1552 (rf > BOARD_HEIGHT-4 || rt > BOARD_HEIGHT-4) ) {
1553 if( (piece == WhitePawn || piece == WhiteQueen) && rt > BOARD_HEIGHT-2 ||
1554 piece == WhiteKnight && rt > BOARD_HEIGHT-3) /* promotion mandatory */
1555 cl.kind = promoChar == '=' ? IllegalMove : WhitePromotionKnight;
1556 else cl.kind = WhitePromotionQueen; /* promotion optional */
1558 } else cl.kind = (promoChar == NULLCHAR || promoChar == 'x' || promoChar == '=') ?
1559 NormalMove : IllegalMove;
1561 if( (int) cl.piece < (int) BlackWazir && (rf < 3 || rt < 3) ) {
1562 if( (piece == BlackPawn || piece == BlackQueen) && rt < 1 ||
1563 piece == BlackKnight && rt < 2 ) /* promotion obligatory */
1564 cl.kind = promoChar == '=' ? IllegalMove : BlackPromotionKnight;
1565 else cl.kind = BlackPromotionQueen; /* promotion optional */
1566 } else cl.kind = (promoChar == NULLCHAR || promoChar == 'x' || promoChar == '=') ?
1567 NormalMove : IllegalMove;
1569 if(cl.kind == WhitePromotionQueen || cl.kind == BlackPromotionQueen) {
1570 /* for optional promotions append '+' or '=' */
1571 if(promoChar == '=') {
1573 cl.kind = NormalMove;
1574 } else *outp++ = '+';
1576 } else if(cl.kind == IllegalMove) {
1577 /* Illegal move specifies any given promotion */
1578 if(promoChar != NULLCHAR && promoChar != 'x') {
1580 *outp++ = ToUpper(promoChar);
1587 /* [HGM] Always long notation for fairies we don't know */
1592 case WhiteGrasshopper:
1593 case BlackGrasshopper:
1595 /* Moving a nonexistent piece */
1599 /* Not a legal move, even ignoring check.
1600 If there was a piece on the from square,
1601 use style "Ng1g3" or "Ng1xe8";
1602 if there was a pawn or nothing (!),
1603 use style "g1g3" or "g1xe8". Use "x"
1604 if a piece was on the to square, even
1605 a piece of the same color.
1608 if (piece != EmptySquare && piece != WhitePawn && piece != BlackPawn) {
1609 *outp++ = ToUpper(PieceToChar(piece));
1614 else { *outp++ = (rf+ONE-'0')/10 + '0';*outp++ = (rf+ONE-'0')%10 + '0'; }
1615 if (board[rt][ft] != EmptySquare) *outp++ = 'x';
1619 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
1620 /* Use promotion suffix style "=Q" */
1621 if (promoChar != NULLCHAR && promoChar != 'x') {
1623 *outp++ = ToUpper(promoChar);
1630 // [HGM] XQ: the following code serves to detect perpetual chasing (Asian rules)
1639 // I guess the following variables logically belong in the closure too, but I was too lazy and used globals
1641 int preyStackPointer, chaseStackPointer;
1644 char rf, ff, rt, ft;
1654 // there are three new callbacks for use with GenLegal: for adding captures, deleting them, and finding a recapture
1656 extern void AtacksCallback P((Board board, int flags, ChessMove kind,
1657 int rf, int ff, int rt, int ft,
1660 void AttacksCallback(board, flags, kind, rf, ff, rt, ft, closure)
1666 { // For adding captures that can lead to chase indictment to the chaseStack
1667 if(board[rt][ft] == EmptySquare) return; // non-capture
1668 if(board[rt][ft] == WhitePawn && rt < BOARD_HEIGHT/2) return; // Pawn before river can be chased
1669 if(board[rt][ft] == BlackPawn && rt >= BOARD_HEIGHT/2) return; // Pawn before river can be chased
1670 if(board[rf][ff] == WhitePawn || board[rf][ff] == BlackPawn) return; // Pawns are allowed to chase
1671 if(board[rf][ff] == WhiteWazir || board[rf][ff] == BlackWazir) return; // King is allowed to chase
1672 // move cannot be excluded from being a chase trivially (based on attacker and victim); save it on chaseStack
1673 chaseStack[chaseStackPointer].rf = rf;
1674 chaseStack[chaseStackPointer].ff = ff;
1675 chaseStack[chaseStackPointer].rt = rt;
1676 chaseStack[chaseStackPointer].ft = ft;
1677 chaseStackPointer++;
1680 extern void ExistingAtacksCallback P((Board board, int flags, ChessMove kind,
1681 int rf, int ff, int rt, int ft,
1684 void ExistingAttacksCallback(board, flags, kind, rf, ff, rt, ft, closure)
1690 { // for removing pre-exsting captures from the chaseStack, to be left with newly created ones
1692 register ChaseClosure *cl = (ChaseClosure *) closure; //closure tells us the move played in the repeat loop
1694 if(board[rt][ft] == EmptySquare) return; // no capture
1695 if(rf == cl->rf && ff == cl->ff) { // attacks with same piece from new position are not considered new
1696 rf = cl->rt; ff = cl->ft; // doctor their fromSquare so they will be recognized in chaseStack
1698 // search move in chaseStack, and delete it if it occurred there (as we know now it is not a new capture)
1699 for(i=0; i<chaseStackPointer; i++) {
1700 if(chaseStack[i].rf == rf && chaseStack[i].ff == ff &&
1701 chaseStack[i].rt == rt && chaseStack[i].ft == ft ) {
1702 // move found on chaseStack, delete it by overwriting with move popped from top of chaseStack
1703 chaseStack[i] = chaseStack[--chaseStackPointer];
1709 extern void ProtectedCallback P((Board board, int flags, ChessMove kind,
1710 int rf, int ff, int rt, int ft,
1713 void ProtectedCallback(board, flags, kind, rf, ff, rt, ft, closure)
1719 { // for determining if a piece (given through the closure) is protected
1720 register ChaseClosure *cl = (ChaseClosure *) closure; // closure tells us where to recapture
1722 if(rt == cl->rt && ft == cl->ft) cl->recaptures++; // count legal recaptures to this square
1723 if(appData.debugMode && board[rt][ft] != EmptySquare)
1724 fprintf(debugFP, "try %c%c%c%c=%d\n", ff+AAA, rf+ONE,ft+AAA, rt+ONE, cl->recaptures);
1727 extern char moveList[MAX_MOVES][MOVE_LEN];
1729 int PerpetualChase(int first, int last)
1730 { // this routine detects if the side to move in the 'first' position is perpetually chasing (when not checking)
1733 ChessSquare captured;
1735 preyStackPointer = 0; // clear stack of chased pieces
1736 for(i=first; i<last; i+=2) { // for all positions with same side to move
1737 if(appData.debugMode) fprintf(debugFP, "judge position %i\n", i);
1738 chaseStackPointer = 0; // clear stack that is going to hold possible chases
1739 // determine all captures possible after the move, and put them on chaseStack
1740 GenLegal(boards[i+1], PosFlags(i), AttacksCallback, &cl);
1741 if(appData.debugMode) { int n;
1742 for(n=0; n<chaseStackPointer; n++)
1743 fprintf(debugFP, "%c%c%c%c ", chaseStack[n].ff+AAA, chaseStack[n].rf+ONE,
1744 chaseStack[n].ft+AAA, chaseStack[n].rt+ONE);
1745 fprintf(debugFP, ": all capts\n");
1747 // determine all captures possible before the move, and delete them from chaseStack
1748 cl.rf = moveList[i][1]-ONE; // prepare closure to pass move that led from i to i+1
1749 cl.ff = moveList[i][0]-AAA+BOARD_LEFT;
1750 cl.rt = moveList[i][3]-ONE;
1751 cl.ft = moveList[i][2]-AAA+BOARD_LEFT;
1752 GenLegal(boards[i], PosFlags(i), ExistingAttacksCallback, &cl);
1753 if(appData.debugMode) { int n;
1754 for(n=0; n<chaseStackPointer; n++)
1755 fprintf(debugFP, "%c%c%c%c ", chaseStack[n].ff+AAA, chaseStack[n].rf+ONE,
1756 chaseStack[n].ft+AAA, chaseStack[n].rt+ONE);
1757 fprintf(debugFP, ": new capts after %c%c%c%c\n", cl.ff+AAA, cl.rf+ONE, cl.ft+AAA, cl.rt+ONE);
1759 // chaseSack now contains all captures made possible by the move
1760 for(j=0; j<chaseStackPointer; j++) { // run through chaseStack to identify true chases
1761 int attacker = (int)boards[i+1][chaseStack[j].rf][chaseStack[j].ff];
1762 int victim = (int)boards[i+1][chaseStack[j].rt][chaseStack[j].ft];
1764 if(attacker >= (int) BlackPawn) attacker = BLACK_TO_WHITE attacker; // convert to white, as piecee type
1765 if(victim >= (int) BlackPawn) victim = BLACK_TO_WHITE victim;
1767 if((attacker == WhiteKnight || attacker == WhiteCannon) && victim == WhiteRook)
1768 continue; // C or H attack on R is always chase; leave on chaseStack
1770 if(attacker == victim) {
1771 if(LegalityTest(boards[i+1], PosFlags(i+1), chaseStack[j].rt,
1772 chaseStack[j].ft, chaseStack[j].rf, chaseStack[j].ff, NULLCHAR) == NormalMove) {
1773 // we can capture back with equal piece, so this is no chase but a sacrifice
1774 chaseStack[j] = chaseStack[--chaseStackPointer]; // delete the capture from the chaseStack
1775 j--; /* ! */ continue;
1780 // the attack is on a lower piece, or on a pinned or blocked equal one
1781 // test if the victim is protected by a true protector. First make the capture.
1782 captured = boards[i+1][chaseStack[j].rt][chaseStack[j].ft];
1783 boards[i+1][chaseStack[j].rt][chaseStack[j].ft] = boards[i+1][chaseStack[j].rf][chaseStack[j].ff];
1784 boards[i+1][chaseStack[j].rf][chaseStack[j].ff] = EmptySquare;
1785 // Then test if the opponent can recapture
1786 cl.recaptures = 0; // prepare closure to pass recapture square and count moves to it
1787 cl.rt = chaseStack[j].rt;
1788 cl.ft = chaseStack[j].ft;
1789 if(appData.debugMode) {
1790 fprintf(debugFP, "test if we can recapture %c%c\n", cl.ft+AAA, cl.rt+ONE);
1792 GenLegal(boards[i+1], PosFlags(i+1), ProtectedCallback, &cl); // try all moves
1793 // unmake the capture
1794 boards[i+1][chaseStack[j].rf][chaseStack[j].ff] = boards[i+1][chaseStack[j].rt][chaseStack[j].ft];
1795 boards[i+1][chaseStack[j].rt][chaseStack[j].ft] = captured;
1796 // if a recapture was found, piece is protected, and we are not chasing it.
1797 if(cl.recaptures) { // attacked piece was defended by true protector, no chase
1798 chaseStack[j] = chaseStack[--chaseStackPointer]; // so delete from chaseStack
1802 // chaseStack now contains all moves that chased
1803 if(appData.debugMode) { int n;
1804 for(n=0; n<chaseStackPointer; n++)
1805 fprintf(debugFP, "%c%c%c%c ", chaseStack[n].ff+AAA, chaseStack[n].rf+ONE,
1806 chaseStack[n].ft+AAA, chaseStack[n].rt+ONE);
1807 fprintf(debugFP, ": chases\n");
1809 if(i == first) { // copy all people chased by first move of repeat cycle to preyStack
1810 for(j=0; j<chaseStackPointer; j++) {
1811 preyStack[j].rank = chaseStack[j].rt;
1812 preyStack[j].file = chaseStack[j].ft;
1814 preyStackPointer = chaseStackPointer;
1817 for(j=0; j<chaseStackPointer; j++) {
1818 for(k=0; k<preyStackPointer; k++) {
1819 // search the victim of each chase move on the preyStack (first occurrence)
1820 if(chaseStack[j].ft == preyStack[k].file && chaseStack[j].rt == preyStack[k].rank ) {
1821 if(k < tail) break; // piece was already identified as still being chased
1822 preyStack[preyStackPointer] = preyStack[tail]; // move chased piece to bottom part of preyStack
1823 preyStack[tail] = preyStack[k]; // by swapping
1824 preyStack[k] = preyStack[preyStackPointer];
1830 preyStackPointer = tail; // keep bottom part of preyStack, popping pieces unchased on move i.
1831 if(appData.debugMode) { int n;
1832 for(n=0; n<preyStackPointer; n++)
1833 fprintf(debugFP, "%c%c ", preyStack[n].file+AAA, preyStack[n].rank+ONE);
1834 fprintf(debugFP, "always chased upto ply %d\n", i);
1836 // now adjust the location of the chased pieces according to opponent move
1837 for(j=0; j<preyStackPointer; j++) {
1838 if(preyStack[j].rank == moveList[i+1][1]-ONE &&
1839 preyStack[j].file == moveList[i+1][0]-AAA+BOARD_LEFT) {
1840 preyStack[j].rank = moveList[i+1][3]-ONE;
1841 preyStack[j].file = moveList[i+1][2]-AAA+BOARD_LEFT;
1846 return preyStackPointer; // if any piece was left on preyStack, it has been perpetually chased