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, 2011, 2012, 2013, 2014 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 */
76 WhitePiece (ChessSquare piece)
78 return (int) piece >= (int) WhitePawn && (int) piece < (int) BlackPawn;
82 BlackPiece (ChessSquare piece)
84 return (int) piece >= (int) BlackPawn && (int) piece < (int) EmptySquare;
89 SameColor (ChessSquare piece1, ChessSquare piece2)
91 return ((int) piece1 >= (int) WhitePawn && /* [HGM] can be > King ! */
92 (int) piece1 < (int) BlackPawn &&
93 (int) piece2 >= (int) WhitePawn &&
94 (int) piece2 < (int) BlackPawn)
95 || ((int) piece1 >= (int) BlackPawn &&
96 (int) piece1 < (int) EmptySquare &&
97 (int) piece2 >= (int) BlackPawn &&
98 (int) piece2 < (int) EmptySquare);
101 #define SameColor(piece1, piece2) (piece1 < EmptySquare && piece2 < EmptySquare && (piece1 < BlackPawn) == (piece2 < BlackPawn) || piece1 == DarkSquare || piece2 == DarkSquare)
104 char pieceToChar[] = {
105 'P', 'N', 'B', 'R', 'Q', 'F', 'E', 'A', 'C', 'W', 'M',
106 'O', 'H', 'I', 'J', 'G', 'D', 'V', 'L', 'S', 'U', 'K',
107 'p', 'n', 'b', 'r', 'q', 'f', 'e', 'a', 'c', 'w', 'm',
108 'o', 'h', 'i', 'j', 'g', 'd', 'v', 'l', 's', 'u', 'k',
110 char pieceNickName[EmptySquare];
113 PieceToChar (ChessSquare p)
115 if((int)p < 0 || (int)p >= (int)EmptySquare) return('x'); /* [HGM] for safety */
116 return pieceToChar[(int) p];
120 PieceToNumber (ChessSquare p) /* [HGM] holdings: count piece type, ignoring non-participating piece types */
123 ChessSquare start = (int)p >= (int)BlackPawn ? BlackPawn : WhitePawn;
125 while(start++ != p) if(pieceToChar[(int)start-1] != '.') i++;
133 if(c == '.') return EmptySquare;
134 for(i=0; i< (int) EmptySquare; i++)
135 if(pieceNickName[i] == c) return (ChessSquare) i;
136 for(i=0; i< (int) EmptySquare; i++)
137 if(pieceToChar[i] == c) return (ChessSquare) i;
142 CopyBoard (Board to, Board from)
146 for (i = 0; i < BOARD_HEIGHT; i++)
147 for (j = 0; j < BOARD_WIDTH; j++)
148 to[i][j] = from[i][j];
149 for (j = 0; j < BOARD_FILES; j++) // [HGM] gamestate: copy castling rights and ep status
150 to[VIRGIN][j] = from[VIRGIN][j],
151 to[CASTLING][j] = from[CASTLING][j];
152 to[HOLDINGS_SET] = 0; // flag used in ICS play
156 CompareBoards (Board board1, Board board2)
160 for (i = 0; i < BOARD_HEIGHT; i++)
161 for (j = 0; j < BOARD_WIDTH; j++) {
162 if (board1[i][j] != board2[i][j])
168 // [HGM] move generation now based on hierarchy of subroutines for rays and combinations of rays
171 SlideForward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
176 if (rt >= BOARD_HEIGHT) break;
177 if (SameColor(board[rf][ff], board[rt][ft])) break;
178 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
179 if (board[rt][ft] != EmptySquare) break;
184 SlideBackward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
190 if (SameColor(board[rf][ff], board[rt][ft])) break;
191 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
192 if (board[rt][ft] != EmptySquare) break;
197 SlideVertical (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
199 SlideForward(board, flags, rf, ff, callback, closure);
200 SlideBackward(board, flags, rf, ff, callback, closure);
204 SlideSideways (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
206 int i, s, rt = rf, ft;
207 for(s = -1; s <= 1; s+= 2) {
210 if (ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
211 if (SameColor(board[rf][ff], board[rt][ft])) break;
212 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
213 if (board[rt][ft] != EmptySquare) break;
219 SlideDiagForward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
222 for(s = -1; s <= 1; s+= 2) {
226 if (rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
227 if (SameColor(board[rf][ff], board[rt][ft])) break;
228 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
229 if (board[rt][ft] != EmptySquare) break;
235 SlideDiagBackward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
238 for(s = -1; s <= 1; s+= 2) {
242 if (rt < 0 || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
243 if (SameColor(board[rf][ff], board[rt][ft])) break;
244 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
245 if (board[rt][ft] != EmptySquare) break;
251 Rook (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
253 SlideVertical(board, flags, rf, ff, callback, closure);
254 SlideSideways(board, flags, rf, ff, callback, closure);
258 Bishop (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
260 SlideDiagForward(board, flags, rf, ff, callback, closure);
261 SlideDiagBackward(board, flags, rf, ff, callback, closure);
265 Sting (Board board, int flags, int rf, int ff, int dy, int dx, MoveCallback callback, VOIDSTAR closure)
266 { // Lion-like move of Horned Falcon and Souring Eagle
267 int ft = ff + dx, rt = rf + dy;
268 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) return;
269 if (!SameColor(board[rf][ff], board[rt][ft]))
270 callback(board, flags, board[rt][ft] != EmptySquare ? FirstLeg : NormalMove, rf, ff, rt, ft, closure);
272 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) return;
273 if (!SameColor(board[rf][ff], board[rt][ft]))
274 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
278 StepForward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
280 int ft = ff, rt = rf + 1;
281 if (rt >= BOARD_HEIGHT) return;
282 if (SameColor(board[rf][ff], board[rt][ft])) return;
283 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
287 StepBackward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
289 int ft = ff, rt = rf - 1;
291 if (SameColor(board[rf][ff], board[rt][ft])) return;
292 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
296 StepSideways (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
300 if (!(rt >= BOARD_HEIGHT || ft >= BOARD_RGHT) && !SameColor(board[rf][ff], board[rt][ft]))
301 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
303 if (!(rt >= BOARD_HEIGHT || ft < BOARD_LEFT) && !SameColor(board[rf][ff], board[rt][ft]))
304 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
308 StepDiagForward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
311 if (rt >= BOARD_HEIGHT) return;
313 if (!(rt >= BOARD_HEIGHT || ft >= BOARD_RGHT) && !SameColor(board[rf][ff], board[rt][ft]))
314 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
316 if (!(rt >= BOARD_HEIGHT || ft < BOARD_LEFT) && !SameColor(board[rf][ff], board[rt][ft]))
317 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
321 StepDiagBackward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
326 if (!(rt < 0 || ft >= BOARD_RGHT) && !SameColor(board[rf][ff], board[rt][ft]))
327 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
329 if (!(rt < 0 || ft < BOARD_LEFT) && !SameColor(board[rf][ff], board[rt][ft]))
330 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
334 StepVertical (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
336 StepForward(board, flags, rf, ff, callback, closure);
337 StepBackward(board, flags, rf, ff, callback, closure);
341 Ferz (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
343 StepDiagForward(board, flags, rf, ff, callback, closure);
344 StepDiagBackward(board, flags, rf, ff, callback, closure);
348 Wazir (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
350 StepVertical(board, flags, rf, ff, callback, closure);
351 StepSideways(board, flags, rf, ff, callback, closure);
355 Knight (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
358 for (i = -1; i <= 1; i += 2)
359 for (j = -1; j <= 1; j += 2)
360 for (s = 1; s <= 2; s++) {
363 if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
364 && ( gameInfo.variant != VariantXiangqi || board[rf+i*(s-1)][ff+j*(2-s)] == EmptySquare)
365 && !SameColor(board[rf][ff], board[rt][ft]))
366 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
370 /* Call callback once for each pseudo-legal move in the given
371 position, except castling moves. A move is pseudo-legal if it is
372 legal, or if it would be legal except that it leaves the king in
373 check. In the arguments, epfile is EP_NONE if the previous move
374 was not a double pawn push, or the file 0..7 if it was, or
375 EP_UNKNOWN if we don't know and want to allow all e.p. captures.
376 Promotion moves generated are to Queen only.
379 GenPseudoLegal (Board board, int flags, MoveCallback callback, VOIDSTAR closure, ChessSquare filter)
380 // speed: only do moves with this piece type
383 int i, j, d, s, fs, rs, rt, ft, m;
384 int epfile = (signed char)board[EP_STATUS]; // [HGM] gamestate: extract ep status from board
385 int promoRank = gameInfo.variant == VariantMakruk || gameInfo.variant == VariantGrand || gameInfo.variant == VariantChuChess ? 3 : 1;
387 for (rf = 0; rf < BOARD_HEIGHT; rf++)
388 for (ff = BOARD_LEFT; ff < BOARD_RGHT; ff++) {
392 if(board[rf][ff] == EmptySquare) continue;
393 if ((flags & F_WHITE_ON_MOVE) != (board[rf][ff] < BlackPawn)) continue; // [HGM] speed: wrong color
395 m = 0; piece = board[rf][ff];
396 if(PieceToChar(piece) == '~')
397 piece = (ChessSquare) ( DEMOTED piece );
398 if(filter != EmptySquare && piece != filter) continue;
399 if(IS_SHOGI(gameInfo.variant))
400 piece = (ChessSquare) ( SHOGI piece );
402 switch ((int)piece) {
403 /* case EmptySquare: [HGM] this is nonsense, and conflicts with Shogi cases */
405 /* can't happen ([HGM] except for faries...) */
409 if(gameInfo.variant == VariantXiangqi) {
410 /* [HGM] capture and move straight ahead in Xiangqi */
411 if (rf < BOARD_HEIGHT-1 &&
412 !SameColor(board[rf][ff], board[rf + 1][ff]) ) {
413 callback(board, flags, NormalMove,
414 rf, ff, rf + 1, ff, closure);
416 /* and move sideways when across the river */
417 for (s = -1; s <= 1; s += 2) {
418 if (rf >= BOARD_HEIGHT>>1 &&
419 ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
420 !WhitePiece(board[rf][ff+s]) ) {
421 callback(board, flags, NormalMove,
422 rf, ff, rf, ff+s, closure);
427 if (rf < BOARD_HEIGHT-1 && board[rf + 1][ff] == EmptySquare) {
428 callback(board, flags,
429 rf >= BOARD_HEIGHT-1-promoRank ? WhitePromotion : NormalMove,
430 rf, ff, rf + 1, ff, closure);
432 if (rf <= (BOARD_HEIGHT>>1)-3 && board[rf+1][ff] == EmptySquare && // [HGM] grand: also on 3rd rank on 10-board
433 gameInfo.variant != VariantShatranj && /* [HGM] */
434 gameInfo.variant != VariantCourier && /* [HGM] */
435 board[rf+2][ff] == EmptySquare ) {
436 callback(board, flags, NormalMove,
437 rf, ff, rf+2, ff, closure);
439 for (s = -1; s <= 1; s += 2) {
440 if (rf < BOARD_HEIGHT-1 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
441 ((flags & F_KRIEGSPIEL_CAPTURE) ||
442 BlackPiece(board[rf + 1][ff + s]))) {
443 callback(board, flags,
444 rf >= BOARD_HEIGHT-1-promoRank ? WhitePromotion : NormalMove,
445 rf, ff, rf + 1, ff + s, closure);
447 if (rf >= BOARD_HEIGHT+1>>1) {// [HGM] grand: 4th & 5th rank on 10-board
448 if (ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
449 (epfile == ff + s || epfile == EP_UNKNOWN) && rf < BOARD_HEIGHT-3 &&
450 board[rf][ff + s] == BlackPawn &&
451 board[rf+1][ff + s] == EmptySquare) {
452 callback(board, flags, WhiteCapturesEnPassant,
453 rf, ff, rf+1, ff + s, closure);
460 if(gameInfo.variant == VariantXiangqi) {
461 /* [HGM] capture straight ahead in Xiangqi */
462 if (rf > 0 && !SameColor(board[rf][ff], board[rf - 1][ff]) ) {
463 callback(board, flags, NormalMove,
464 rf, ff, rf - 1, ff, closure);
466 /* and move sideways when across the river */
467 for (s = -1; s <= 1; s += 2) {
468 if (rf < BOARD_HEIGHT>>1 &&
469 ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
470 !BlackPiece(board[rf][ff+s]) ) {
471 callback(board, flags, NormalMove,
472 rf, ff, rf, ff+s, closure);
477 if (rf > 0 && board[rf - 1][ff] == EmptySquare) {
478 callback(board, flags,
479 rf <= promoRank ? BlackPromotion : NormalMove,
480 rf, ff, rf - 1, ff, closure);
482 if (rf >= (BOARD_HEIGHT+1>>1)+2 && board[rf-1][ff] == EmptySquare && // [HGM] grand
483 gameInfo.variant != VariantShatranj && /* [HGM] */
484 gameInfo.variant != VariantCourier && /* [HGM] */
485 board[rf-2][ff] == EmptySquare) {
486 callback(board, flags, NormalMove,
487 rf, ff, rf-2, ff, closure);
489 for (s = -1; s <= 1; s += 2) {
490 if (rf > 0 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
491 ((flags & F_KRIEGSPIEL_CAPTURE) ||
492 WhitePiece(board[rf - 1][ff + s]))) {
493 callback(board, flags,
494 rf <= promoRank ? BlackPromotion : NormalMove,
495 rf, ff, rf - 1, ff + s, closure);
497 if (rf < BOARD_HEIGHT>>1) {
498 if (ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
499 (epfile == ff + s || epfile == EP_UNKNOWN) && rf > 2 &&
500 board[rf][ff + s] == WhitePawn &&
501 board[rf-1][ff + s] == EmptySquare) {
502 callback(board, flags, BlackCapturesEnPassant,
503 rf, ff, rf-1, ff + s, closure);
513 for (i = -1; i <= 1; i += 2)
514 for (j = -1; j <= 1; j += 2)
515 for (s = 1; s <= 2; s++) {
518 if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
519 && ( gameInfo.variant != VariantXiangqi || board[rf+i*(s-1)][ff+j*(2-s)] == EmptySquare)
520 && !SameColor(board[rf][ff], board[rt][ft]))
521 callback(board, flags, NormalMove,
522 rf, ff, rt, ft, closure);
526 case SHOGI WhiteKnight:
527 for (s = -1; s <= 1; s += 2) {
528 if (rf < BOARD_HEIGHT-2 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
529 !SameColor(board[rf][ff], board[rf + 2][ff + s])) {
530 callback(board, flags, NormalMove,
531 rf, ff, rf + 2, ff + s, closure);
536 case SHOGI BlackKnight:
537 for (s = -1; s <= 1; s += 2) {
538 if (rf > 1 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
539 !SameColor(board[rf][ff], board[rf - 2][ff + s])) {
540 callback(board, flags, NormalMove,
541 rf, ff, rf - 2, ff + s, closure);
548 for (d = 0; d <= 1; d++)
549 for (s = -1; s <= 1; s += 2) {
552 rt = rf + (i * s) * d;
553 ft = ff + (i * s) * (1 - d);
554 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
555 if (m == 0 && board[rt][ft] == EmptySquare)
556 callback(board, flags, NormalMove,
557 rf, ff, rt, ft, closure);
558 if (m == 1 && board[rt][ft] != EmptySquare &&
559 !SameColor(board[rf][ff], board[rt][ft]) )
560 callback(board, flags, NormalMove,
561 rf, ff, rt, ft, closure);
562 if (board[rt][ft] != EmptySquare && m++) break;
567 /* Gold General (and all its promoted versions) . First do the */
568 /* diagonal forward steps, then proceed as normal Wazir */
569 case SHOGI (PROMOTED WhitePawn):
570 if(gameInfo.variant == VariantShogi) goto WhiteGold;
571 case SHOGI (PROMOTED BlackPawn):
572 if(gameInfo.variant == VariantShogi) goto BlackGold;
573 SlideVertical(board, flags, rf, ff, callback, closure);
576 case SHOGI (PROMOTED WhiteKnight):
577 if(gameInfo.variant == VariantShogi) goto WhiteGold;
578 case SHOGI BlackDrunk:
579 case SHOGI BlackAlfil:
580 Ferz(board, flags, rf, ff, callback, closure);
581 StepSideways(board, flags, rf, ff, callback, closure);
582 StepBackward(board, flags, rf, ff, callback, closure);
585 case SHOGI (PROMOTED BlackKnight):
586 if(gameInfo.variant == VariantShogi) goto BlackGold;
587 case SHOGI WhiteDrunk:
588 case SHOGI WhiteAlfil:
589 Ferz(board, flags, rf, ff, callback, closure);
590 StepSideways(board, flags, rf, ff, callback, closure);
591 StepForward(board, flags, rf, ff, callback, closure);
595 case SHOGI WhiteStag:
596 case SHOGI BlackStag:
597 if(gameInfo.variant == VariantShogi) goto BlackGold;
598 SlideVertical(board, flags, rf, ff, callback, closure);
599 Ferz(board, flags, rf, ff, callback, closure);
600 StepSideways(board, flags, rf, ff, callback, closure);
603 case SHOGI (PROMOTED WhiteQueen):
604 case SHOGI WhiteTokin:
605 case SHOGI WhiteWazir:
607 StepDiagForward(board, flags, rf, ff, callback, closure);
608 Wazir(board, flags, rf, ff, callback, closure);
611 case SHOGI (PROMOTED BlackQueen):
612 case SHOGI BlackTokin:
613 case SHOGI BlackWazir:
615 StepDiagBackward(board, flags, rf, ff, callback, closure);
616 Wazir(board, flags, rf, ff, callback, closure);
621 Wazir(board, flags, rf, ff, callback, closure);
624 case SHOGI WhiteMarshall:
625 case SHOGI BlackMarshall:
626 Ferz(board, flags, rf, ff, callback, closure);
627 for (d = 0; d <= 1; d++)
628 for (s = -2; s <= 2; s += 4) {
630 ft = ff + s * (1 - d);
631 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) continue;
632 if (!SameColor(board[rf][ff], board[rt][ft]) )
633 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
637 case SHOGI WhiteAngel:
638 case SHOGI BlackAngel:
639 Wazir(board, flags, rf, ff, callback, closure);
643 /* [HGM] support Shatranj pieces */
644 for (rs = -1; rs <= 1; rs += 2)
645 for (fs = -1; fs <= 1; fs += 2) {
648 if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
649 && ( gameInfo.variant != VariantXiangqi ||
650 board[rf+rs][ff+fs] == EmptySquare && (2*rf < BOARD_HEIGHT) == (2*rt < BOARD_HEIGHT) )
652 && !SameColor(board[rf][ff], board[rt][ft]))
653 callback(board, flags, NormalMove,
654 rf, ff, rt, ft, closure);
655 if(gameInfo.variant == VariantShatranj || gameInfo.variant == VariantCourier ||
656 gameInfo.variant == VariantChu || gameInfo.variant == VariantXiangqi) continue; // classical Alfil
657 rt = rf + rs; // in unknown variant we assume Modern Elephant, which can also do one step
659 if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
660 && !SameColor(board[rf][ff], board[rt][ft]))
661 callback(board, flags, NormalMove,
662 rf, ff, rt, ft, closure);
664 if(gameInfo.variant == VariantSpartan)
665 for(fs = -1; fs <= 1; fs += 2) {
667 if (!(ft < BOARD_LEFT || ft >= BOARD_RGHT) && board[rf][ft] == EmptySquare)
668 callback(board, flags, NormalMove, rf, ff, rf, ft, closure);
672 /* Make Dragon-Horse also do Dababba moves outside Shogi, for better disambiguation in variant Fairy */
675 if(gameInfo.variant == VariantChuChess) goto DragonHorse;
676 for (d = 0; d <= 1; d++) // Dababba moves that Rook cannot do
677 for (s = -2; s <= 2; s += 4) {
679 ft = ff + s * (1 - d);
680 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) continue;
681 if (SameColor(board[rf][ff], board[rt][ft])) continue;
682 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
685 /* Shogi Dragon Horse has to continue with Wazir after Bishop */
686 case SHOGI WhiteCardinal:
687 case SHOGI BlackCardinal:
688 case SHOGI WhitePCardinal:
689 case SHOGI BlackPCardinal:
691 Bishop(board, flags, rf, ff, callback, closure);
692 Wazir(board, flags, rf, ff, callback, closure);
695 /* Capablanca Archbishop continues as Knight */
698 Knight(board, flags, rf, ff, callback, closure);
700 /* Shogi Bishops are ordinary Bishops */
701 case SHOGI WhiteBishop:
702 case SHOGI BlackBishop:
703 case SHOGI WhitePBishop:
704 case SHOGI BlackPBishop:
707 Bishop(board, flags, rf, ff, callback, closure);
710 /* Shogi Lance is unlike anything, and asymmetric at that */
711 case SHOGI WhiteQueen:
712 if(gameInfo.variant == VariantChu) goto doQueen;
716 if (rt >= BOARD_HEIGHT) break;
717 if (SameColor(board[rf][ff], board[rt][ft])) break;
718 callback(board, flags, NormalMove,
719 rf, ff, rt, ft, closure);
720 if (board[rt][ft] != EmptySquare) break;
724 case SHOGI BlackQueen:
725 if(gameInfo.variant == VariantChu) goto doQueen;
730 if (SameColor(board[rf][ff], board[rt][ft])) break;
731 callback(board, flags, NormalMove,
732 rf, ff, rt, ft, closure);
733 if (board[rt][ft] != EmptySquare) break;
737 /* Make Dragon-King Dababba & Rook-like outside Shogi, for better disambiguation in variant Fairy */
740 if(gameInfo.variant == VariantChuChess) goto DragonKing;
741 for (d = 0; d <= 1; d++) // Dababba moves that Rook cannot do
742 for (s = -2; s <= 2; s += 4) {
744 ft = ff + s * (1 - d);
745 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT || board[rf+rt>>1][ff+ft>>1] == EmptySquare) continue;
746 if (SameColor(board[rf][ff], board[rt][ft])) continue;
747 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
749 if(gameInfo.variant == VariantSpartan) rookRange = 2; // in Spartan Chess restrict range to modern Dababba
752 /* Shogi Dragon King has to continue as Ferz after Rook moves */
753 case SHOGI WhiteDragon:
754 case SHOGI BlackDragon:
755 case SHOGI WhitePDragon:
756 case SHOGI BlackPDragon:
758 Rook(board, flags, rf, ff, callback, closure);
759 Ferz(board, flags, rf, ff, callback, closure);
763 /* Capablanca Chancellor sets flag to continue as Knight */
766 Rook(board, flags, rf, ff, callback, closure);
767 if(gameInfo.variant == VariantSpartan) // in Spartan Chess Chancellor is used for Dragon King.
768 Ferz(board, flags, rf, ff, callback, closure);
770 Knight(board, flags, rf, ff, callback, closure);
773 /* Shogi Rooks are ordinary Rooks */
774 case SHOGI WhiteRook:
775 case SHOGI BlackRook:
776 case SHOGI WhitePRook:
777 case SHOGI BlackPRook:
781 Rook(board, flags, rf, ff, callback, closure);
786 case SHOGI WhiteMother:
787 case SHOGI BlackMother:
789 Rook(board, flags, rf, ff, callback, closure);
790 Bishop(board, flags, rf, ff, callback, closure);
793 case SHOGI WhitePawn:
794 StepForward(board, flags, rf, ff, callback, closure);
797 case SHOGI BlackPawn:
798 StepBackward(board, flags, rf, ff, callback, closure);
802 if(gameInfo.variant != VariantMakruk && gameInfo.variant != VariantASEAN) goto commoner;
803 case SHOGI WhiteFerz:
804 Ferz(board, flags, rf, ff, callback, closure);
805 StepForward(board, flags, rf, ff, callback, closure);
809 if(gameInfo.variant != VariantMakruk && gameInfo.variant != VariantASEAN) goto commoner;
810 case SHOGI BlackFerz:
811 StepBackward(board, flags, rf, ff, callback, closure);
815 /* [HGM] support Shatranj pieces */
816 Ferz(board, flags, rf, ff, callback, closure);
821 Knight(board, flags, rf, ff, callback, closure); // [HGM] superchess: use for Centaur
824 case SHOGI WhiteMonarch:
825 case SHOGI BlackMonarch:
826 case SHOGI WhiteKing:
827 case SHOGI BlackKing:
830 Ferz(board, flags, rf, ff, callback, closure);
831 Wazir(board, flags, rf, ff, callback, closure);
834 case WhiteNightrider:
835 case BlackNightrider:
836 for (i = -1; i <= 1; i += 2)
837 for (j = -1; j <= 1; j += 2)
838 for (s = 1; s <= 2; s++) { int k;
842 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
843 if (SameColor(board[rf][ff], board[rt][ft])) break;
844 callback(board, flags, NormalMove,
845 rf, ff, rt, ft, closure);
846 if (board[rt][ft] != EmptySquare) break;
852 Bishop(board, flags, rf, ff, callback, closure);
853 Rook(board, flags, rf, ff, callback, closure);
854 Knight(board, flags, rf, ff, callback, closure);
857 // Use Lance as Berolina / Spartan Pawn.
859 if(gameInfo.variant == VariantSuper) goto Amazon;
860 if (rf < BOARD_HEIGHT-1 && BlackPiece(board[rf + 1][ff]))
861 callback(board, flags,
862 rf >= BOARD_HEIGHT-1-promoRank ? WhitePromotion : NormalMove,
863 rf, ff, rf + 1, ff, closure);
864 for (s = -1; s <= 1; s += 2) {
865 if (rf < BOARD_HEIGHT-1 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT && board[rf + 1][ff + s] == EmptySquare)
866 callback(board, flags,
867 rf >= BOARD_HEIGHT-1-promoRank ? WhitePromotion : NormalMove,
868 rf, ff, rf + 1, ff + s, closure);
869 if (rf == 1 && ff + 2*s >= BOARD_LEFT && ff + 2*s < BOARD_RGHT && board[3][ff + 2*s] == EmptySquare )
870 callback(board, flags, NormalMove, rf, ff, 3, ff + 2*s, closure);
875 if(gameInfo.variant == VariantSuper) goto Amazon;
876 if (rf > 0 && WhitePiece(board[rf - 1][ff]))
877 callback(board, flags,
878 rf <= promoRank ? BlackPromotion : NormalMove,
879 rf, ff, rf - 1, ff, closure);
880 for (s = -1; s <= 1; s += 2) {
881 if (rf > 0 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT && board[rf - 1][ff + s] == EmptySquare)
882 callback(board, flags,
883 rf <= promoRank ? BlackPromotion : NormalMove,
884 rf, ff, rf - 1, ff + s, closure);
885 if (rf == BOARD_HEIGHT-2 && ff + 2*s >= BOARD_LEFT && ff + 2*s < BOARD_RGHT && board[rf-2][ff + 2*s] == EmptySquare )
886 callback(board, flags, NormalMove, rf, ff, rf-2, ff + 2*s, closure);
890 case SHOGI WhiteNothing:
891 case SHOGI BlackNothing:
892 case SHOGI WhiteLion:
893 case SHOGI BlackLion:
896 for(rt = rf - 2; rt <= rf + 2; rt++) for(ft = ff - 2; ft <= ff + 2; ft++) {
897 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) continue;
898 if (!(ff == ft && rf == rt) && SameColor(board[rf][ff], board[rt][ft])) continue;
899 callback(board, flags, (rt-rf)*(rt-rf) + (ff-ft)*(ff-ft) < 3 && board[rt][ft] != EmptySquare ? FirstLeg : NormalMove,
900 rf, ff, rt, ft, closure);
904 case SHOGI WhiteFalcon:
905 case SHOGI BlackFalcon:
906 case SHOGI WhitePDagger:
907 case SHOGI BlackPDagger:
908 SlideSideways(board, flags, rf, ff, callback, closure);
909 StepVertical(board, flags, rf, ff, callback, closure);
912 case SHOGI WhiteCobra:
913 case SHOGI BlackCobra:
914 StepVertical(board, flags, rf, ff, callback, closure);
917 case SHOGI (PROMOTED WhiteFerz):
918 if(gameInfo.variant == VariantShogi) goto WhiteGold;
919 case SHOGI (PROMOTED BlackFerz):
920 if(gameInfo.variant == VariantShogi) goto BlackGold;
921 case SHOGI WhitePSword:
922 case SHOGI BlackPSword:
923 SlideVertical(board, flags, rf, ff, callback, closure);
924 StepSideways(board, flags, rf, ff, callback, closure);
927 case SHOGI WhiteUnicorn:
928 case SHOGI BlackUnicorn:
929 Ferz(board, flags, rf, ff, callback, closure);
930 StepVertical(board, flags, rf, ff, callback, closure);
934 StepDiagForward(board, flags, rf, ff, callback, closure);
935 StepVertical(board, flags, rf, ff, callback, closure);
939 StepDiagBackward(board, flags, rf, ff, callback, closure);
940 StepVertical(board, flags, rf, ff, callback, closure);
943 case SHOGI WhiteHCrown:
944 case SHOGI BlackHCrown:
945 Bishop(board, flags, rf, ff, callback, closure);
946 SlideSideways(board, flags, rf, ff, callback, closure);
949 case SHOGI WhiteCrown:
950 case SHOGI BlackCrown:
951 Bishop(board, flags, rf, ff, callback, closure);
952 SlideVertical(board, flags, rf, ff, callback, closure);
955 case SHOGI WhiteHorned:
956 Sting(board, flags, rf, ff, 1, 0, callback, closure);
957 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
958 if(killX >= 0) break;
959 Bishop(board, flags, rf, ff, callback, closure);
960 SlideSideways(board, flags, rf, ff, callback, closure);
961 SlideBackward(board, flags, rf, ff, callback, closure);
964 case SHOGI BlackHorned:
965 Sting(board, flags, rf, ff, -1, 0, callback, closure);
966 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
967 if(killX >= 0) break;
968 Bishop(board, flags, rf, ff, callback, closure);
969 SlideSideways(board, flags, rf, ff, callback, closure);
970 SlideForward(board, flags, rf, ff, callback, closure);
973 case SHOGI WhiteEagle:
974 Sting(board, flags, rf, ff, 1, 1, callback, closure);
975 Sting(board, flags, rf, ff, 1, -1, callback, closure);
976 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
977 if(killX >= 0) break;
978 Rook(board, flags, rf, ff, callback, closure);
979 SlideDiagBackward(board, flags, rf, ff, callback, closure);
982 case SHOGI BlackEagle:
983 Sting(board, flags, rf, ff, -1, 1, callback, closure);
984 Sting(board, flags, rf, ff, -1, -1, callback, closure);
985 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
986 if(killX >= 0) break;
987 Rook(board, flags, rf, ff, callback, closure);
988 SlideDiagForward(board, flags, rf, ff, callback, closure);
991 case SHOGI WhiteDolphin:
992 case SHOGI BlackHorse:
993 SlideDiagBackward(board, flags, rf, ff, callback, closure);
994 SlideVertical(board, flags, rf, ff, callback, closure);
997 case SHOGI BlackDolphin:
998 case SHOGI WhiteHorse:
999 SlideDiagForward(board, flags, rf, ff, callback, closure);
1000 SlideVertical(board, flags, rf, ff, callback, closure);
1003 case SHOGI WhiteLance:
1004 SlideForward(board, flags, rf, ff, callback, closure);
1007 case SHOGI BlackLance:
1008 SlideBackward(board, flags, rf, ff, callback, closure);
1011 case WhiteFalcon: // [HGM] wild: for wildcards, self-capture symbolizes move to anywhere
1015 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1028 int rFilter, fFilter; // [HGM] speed: sorry, but I get a bit tired of this closure madness
1029 Board xqCheckers, nullBoard;
1031 extern void GenLegalCallback P((Board board, int flags, ChessMove kind,
1032 int rf, int ff, int rt, int ft,
1036 GenLegalCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1038 register GenLegalClosure *cl = (GenLegalClosure *) closure;
1040 if(rFilter >= 0 && rFilter != rt || fFilter >= 0 && fFilter != ft) return; // [HGM] speed: ignore moves with wrong to-square
1042 if (board[EP_STATUS] == EP_IRON_LION && (board[rt][ft] == WhiteLion || board[rt][ft] == BlackLion)) return; //[HGM] lion
1044 if (!(flags & F_IGNORE_CHECK) ) {
1045 int check, promo = (gameInfo.variant == VariantSpartan && kind == BlackPromotion);
1048 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++)
1049 kings += (board[r][f] == BlackKing);
1053 board[rf][ff] = BlackKing; // [HGM] spartan: promote to King before check-test
1055 check = CheckTest(board, flags, rf, ff, rt, ft,
1056 kind == WhiteCapturesEnPassant ||
1057 kind == BlackCapturesEnPassant);
1058 if(promo) board[rf][ff] = BlackLance;
1061 if (flags & F_ATOMIC_CAPTURE) {
1062 if (board[rt][ft] != EmptySquare ||
1063 kind == WhiteCapturesEnPassant || kind == BlackCapturesEnPassant) {
1065 ChessSquare king = (flags & F_WHITE_ON_MOVE) ? WhiteKing : BlackKing;
1066 if (board[rf][ff] == king) return;
1067 for (r = rt-1; r <= rt+1; r++) {
1068 for (f = ft-1; f <= ft+1; f++) {
1069 if (r >= 0 && r < BOARD_HEIGHT && f >= BOARD_LEFT && f < BOARD_RGHT &&
1070 board[r][f] == king) return;
1075 cl->cb(board, flags, kind, rf, ff, rt, ft, cl->cl);
1082 int captures; // [HGM] losers
1083 } LegalityTestClosure;
1086 /* Like GenPseudoLegal, but (1) include castling moves, (2) unless
1087 F_IGNORE_CHECK is set in the flags, omit moves that would leave the
1088 king in check, and (3) if F_ATOMIC_CAPTURE is set in the flags, omit
1089 moves that would destroy your own king. The CASTLE_OK flags are
1090 true if castling is not yet ruled out by a move of the king or
1091 rook. Return TRUE if the player on move is currently in check and
1092 F_IGNORE_CHECK is not set. [HGM] add castlingRights parameter */
1094 GenLegal (Board board, int flags, MoveCallback callback, VOIDSTAR closure, ChessSquare filter)
1097 int ff, ft, k, left, right, swap;
1098 int ignoreCheck = (flags & F_IGNORE_CHECK) != 0;
1099 ChessSquare wKing = WhiteKing, bKing = BlackKing, *castlingRights = board[CASTLING];
1100 int inCheck = !ignoreCheck && CheckTest(board, flags, -1, -1, -1, -1, FALSE); // kludge alert: this would mark pre-existing checkers if status==1
1104 xqCheckers[EP_STATUS] *= 2; // quasi: if previous CheckTest has been marking, we now set flag for suspending same checkers
1105 if(filter == EmptySquare) rFilter = fFilter = -1; // [HGM] speed: do not filter on square if we do not filter on piece
1106 GenPseudoLegal(board, flags, GenLegalCallback, (VOIDSTAR) &cl, filter);
1108 if (inCheck) return TRUE;
1110 /* Generate castling moves */
1111 if(gameInfo.variant == VariantKnightmate) { /* [HGM] Knightmate */
1112 wKing = WhiteUnicorn; bKing = BlackUnicorn;
1115 for (ff = BOARD_WIDTH>>1; ff >= (BOARD_WIDTH-1)>>1; ff-- /*ics wild 1*/) {
1116 if ((flags & F_WHITE_ON_MOVE) &&
1117 (flags & F_WHITE_KCASTLE_OK) &&
1118 board[0][ff] == wKing &&
1119 board[0][ff + 1] == EmptySquare &&
1120 board[0][ff + 2] == EmptySquare &&
1121 board[0][BOARD_RGHT-3] == EmptySquare &&
1122 board[0][BOARD_RGHT-2] == EmptySquare &&
1123 board[0][BOARD_RGHT-1] == WhiteRook &&
1124 castlingRights[0] != NoRights && /* [HGM] check rights */
1125 ( castlingRights[2] == ff || castlingRights[6] == ff ) &&
1127 (!CheckTest(board, flags, 0, ff, 0, ff + 1, FALSE) &&
1128 !CheckTest(board, flags, 0, ff, 0, BOARD_RGHT-3, FALSE) &&
1129 (gameInfo.variant != VariantJanus || !CheckTest(board, flags, 0, ff, 0, BOARD_RGHT-2, FALSE)) &&
1130 !CheckTest(board, flags, 0, ff, 0, ff + 2, FALSE)))) {
1132 callback(board, flags,
1133 ff==BOARD_WIDTH>>1 ? WhiteKingSideCastle : WhiteKingSideCastleWild,
1134 0, ff, 0, ff + ((gameInfo.boardWidth+2)>>2) + (gameInfo.variant == VariantJanus), closure);
1136 if ((flags & F_WHITE_ON_MOVE) &&
1137 (flags & F_WHITE_QCASTLE_OK) &&
1138 board[0][ff] == wKing &&
1139 board[0][ff - 1] == EmptySquare &&
1140 board[0][ff - 2] == EmptySquare &&
1141 board[0][BOARD_LEFT+2] == EmptySquare &&
1142 board[0][BOARD_LEFT+1] == EmptySquare &&
1143 board[0][BOARD_LEFT+0] == WhiteRook &&
1144 castlingRights[1] != NoRights && /* [HGM] check rights */
1145 ( castlingRights[2] == ff || castlingRights[6] == ff ) &&
1147 (!CheckTest(board, flags, 0, ff, 0, ff - 1, FALSE) &&
1148 !CheckTest(board, flags, 0, ff, 0, BOARD_LEFT+3, FALSE) &&
1149 !CheckTest(board, flags, 0, ff, 0, ff - 2, FALSE)))) {
1151 callback(board, flags,
1152 ff==BOARD_WIDTH>>1 ? WhiteQueenSideCastle : WhiteQueenSideCastleWild,
1153 0, ff, 0, ff - ((gameInfo.boardWidth+2)>>2), closure);
1155 if (!(flags & F_WHITE_ON_MOVE) &&
1156 (flags & F_BLACK_KCASTLE_OK) &&
1157 board[BOARD_HEIGHT-1][ff] == bKing &&
1158 board[BOARD_HEIGHT-1][ff + 1] == EmptySquare &&
1159 board[BOARD_HEIGHT-1][ff + 2] == EmptySquare &&
1160 board[BOARD_HEIGHT-1][BOARD_RGHT-3] == EmptySquare &&
1161 board[BOARD_HEIGHT-1][BOARD_RGHT-2] == EmptySquare &&
1162 board[BOARD_HEIGHT-1][BOARD_RGHT-1] == BlackRook &&
1163 castlingRights[3] != NoRights && /* [HGM] check rights */
1164 ( castlingRights[5] == ff || castlingRights[7] == ff ) &&
1166 (!CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff + 1, FALSE) &&
1167 !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, BOARD_RGHT-3, FALSE) &&
1168 (gameInfo.variant != VariantJanus || !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, BOARD_RGHT-2, FALSE)) &&
1169 !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff + 2, FALSE)))) {
1171 callback(board, flags,
1172 ff==BOARD_WIDTH>>1 ? BlackKingSideCastle : BlackKingSideCastleWild,
1173 BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff + ((gameInfo.boardWidth+2)>>2) + (gameInfo.variant == VariantJanus), closure);
1175 if (!(flags & F_WHITE_ON_MOVE) &&
1176 (flags & F_BLACK_QCASTLE_OK) &&
1177 board[BOARD_HEIGHT-1][ff] == bKing &&
1178 board[BOARD_HEIGHT-1][ff - 1] == EmptySquare &&
1179 board[BOARD_HEIGHT-1][ff - 2] == EmptySquare &&
1180 board[BOARD_HEIGHT-1][BOARD_LEFT+2] == EmptySquare &&
1181 board[BOARD_HEIGHT-1][BOARD_LEFT+1] == EmptySquare &&
1182 board[BOARD_HEIGHT-1][BOARD_LEFT+0] == BlackRook &&
1183 castlingRights[4] != NoRights && /* [HGM] check rights */
1184 ( castlingRights[5] == ff || castlingRights[7] == ff ) &&
1186 (!CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff - 1, FALSE) &&
1187 !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, BOARD_LEFT+3, FALSE) &&
1188 !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff - 2, FALSE)))) {
1190 callback(board, flags,
1191 ff==BOARD_WIDTH>>1 ? BlackQueenSideCastle : BlackQueenSideCastleWild,
1192 BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff - ((gameInfo.boardWidth+2)>>2), closure);
1196 if((swap = gameInfo.variant == VariantSChess) || flags & F_FRC_TYPE_CASTLING) {
1198 /* generate all potential FRC castling moves (KxR), ignoring flags */
1199 /* [HGM] test if the Rooks we find have castling rights */
1200 /* In S-Chess we generate RxK for allowed castlings, for gating at Rook square */
1203 if ((flags & F_WHITE_ON_MOVE) != 0) {
1204 ff = castlingRights[2]; /* King file if we have any rights */
1205 if(ff != NoRights && board[0][ff] == WhiteKing) {
1206 if (appData.debugMode) {
1207 fprintf(debugFP, "FRC castling, %d %d %d %d %d %d\n",
1208 castlingRights[0],castlingRights[1],ff,castlingRights[3],castlingRights[4],castlingRights[5]);
1210 ft = castlingRights[0]; /* Rook file if we have H-side rights */
1212 right = BOARD_RGHT-2;
1213 if(ff == BOARD_RGHT-2) left = right = ff-1; /* special case */
1214 for(k=left; k<=right && ft != NoRights; k++) /* first test if blocked */
1215 if(k != ft && board[0][k] != EmptySquare) ft = NoRights;
1216 for(k=left; k<right && ft != NoRights; k++) /* then if not checked */
1217 if(!ignoreCheck && CheckTest(board, flags, 0, ff, 0, k, FALSE)) ft = NoRights;
1218 if(ft != NoRights && board[0][ft] == WhiteRook) {
1219 if(flags & F_FRC_TYPE_CASTLING) callback(board, flags, WhiteHSideCastleFR, 0, ff, 0, ft, closure);
1220 if(swap) callback(board, flags, WhiteHSideCastleFR, 0, ft, 0, ff, closure);
1223 ft = castlingRights[1]; /* Rook file if we have A-side rights */
1224 left = BOARD_LEFT+2;
1226 if(ff <= BOARD_LEFT+2) { left = ff+1; right = BOARD_LEFT+3; }
1227 for(k=left; k<=right && ft != NoRights; k++) /* first test if blocked */
1228 if(k != ft && board[0][k] != EmptySquare) ft = NoRights;
1229 if(ft == 0 && ff != 1 && board[0][1] != EmptySquare) ft = NoRights; /* Rook can be blocked on b1 */
1230 if(ff > BOARD_LEFT+2)
1231 for(k=left+1; k<=right && ft != NoRights; k++) /* then if not checked */
1232 if(!ignoreCheck && CheckTest(board, flags, 0, ff, 0, k, FALSE)) ft = NoRights;
1233 if(ft != NoRights && board[0][ft] == WhiteRook) {
1234 if(flags & F_FRC_TYPE_CASTLING) callback(board, flags, WhiteASideCastleFR, 0, ff, 0, ft, closure);
1235 if(swap) callback(board, flags, WhiteASideCastleFR, 0, ft, 0, ff, closure);
1239 ff = castlingRights[5]; /* King file if we have any rights */
1240 if(ff != NoRights && board[BOARD_HEIGHT-1][ff] == BlackKing) {
1241 ft = castlingRights[3]; /* Rook file if we have H-side rights */
1243 right = BOARD_RGHT-2;
1244 if(ff == BOARD_RGHT-2) left = right = ff-1; /* special case */
1245 for(k=left; k<=right && ft != NoRights; k++) /* first test if blocked */
1246 if(k != ft && board[BOARD_HEIGHT-1][k] != EmptySquare) ft = NoRights;
1247 for(k=left; k<right && ft != NoRights; k++) /* then if not checked */
1248 if(!ignoreCheck && CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, k, FALSE)) ft = NoRights;
1249 if(ft != NoRights && board[BOARD_HEIGHT-1][ft] == BlackRook) {
1250 if(flags & F_FRC_TYPE_CASTLING) callback(board, flags, BlackHSideCastleFR, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ft, closure);
1251 if(swap) callback(board, flags, BlackHSideCastleFR, BOARD_HEIGHT-1, ft, BOARD_HEIGHT-1, ff, closure);
1254 ft = castlingRights[4]; /* Rook file if we have A-side rights */
1255 left = BOARD_LEFT+2;
1257 if(ff <= BOARD_LEFT+2) { left = ff+1; right = BOARD_LEFT+3; }
1258 for(k=left; k<=right && ft != NoRights; k++) /* first test if blocked */
1259 if(k != ft && board[BOARD_HEIGHT-1][k] != EmptySquare) ft = NoRights;
1260 if(ft == 0 && ff != 1 && board[BOARD_HEIGHT-1][1] != EmptySquare) ft = NoRights; /* Rook can be blocked on b8 */
1261 if(ff > BOARD_LEFT+2)
1262 for(k=left+1; k<=right && ft != NoRights; k++) /* then if not checked */
1263 if(!ignoreCheck && CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, k, FALSE)) ft = NoRights;
1264 if(ft != NoRights && board[BOARD_HEIGHT-1][ft] == BlackRook) {
1265 if(flags & F_FRC_TYPE_CASTLING) callback(board, flags, BlackASideCastleFR, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ft, closure);
1266 if(swap) callback(board, flags, BlackASideCastleFR, BOARD_HEIGHT-1, ft, BOARD_HEIGHT-1, ff, closure);
1283 extern void CheckTestCallback P((Board board, int flags, ChessMove kind,
1284 int rf, int ff, int rt, int ft,
1289 CheckTestCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1291 register CheckTestClosure *cl = (CheckTestClosure *) closure;
1293 if (rt == cl->rking && ft == cl->fking) {
1294 if(xqCheckers[EP_STATUS] >= 2 && xqCheckers[rf][ff]) return; // checker is piece with suspended checking power
1296 xqCheckers[rf][ff] = xqCheckers[EP_STATUS] & 1; // remember who is checking (if status == 1)
1298 if( board[EP_STATUS] == EP_ROYAL_LION && (board[rt][ft] == WhiteLion || board[rt][ft] == BlackLion)
1299 && (gameInfo.variant != VariantLion || board[rf][ff] != WhiteKing && board[rf][ff] != BlackKing) )
1300 cl->check++; // [HGM] lion: forbidden counterstrike against Lion equated to putting yourself in check
1304 /* If the player on move were to move from (rf, ff) to (rt, ft), would
1305 he leave himself in check? Or if rf == -1, is the player on move
1306 in check now? enPassant must be TRUE if the indicated move is an
1307 e.p. capture. The possibility of castling out of a check along the
1308 back rank is not accounted for (i.e., we still return nonzero), as
1309 this is illegal anyway. Return value is the number of times the
1310 king is in check. */
1312 CheckTest (Board board, int flags, int rf, int ff, int rt, int ft, int enPassant)
1314 CheckTestClosure cl;
1315 ChessSquare king = flags & F_WHITE_ON_MOVE ? WhiteKing : BlackKing;
1316 ChessSquare captured = EmptySquare, ep=0, trampled=0;
1317 /* Suppress warnings on uninitialized variables */
1319 if(gameInfo.variant == VariantXiangqi)
1320 king = flags & F_WHITE_ON_MOVE ? WhiteWazir : BlackWazir;
1321 if(gameInfo.variant == VariantKnightmate)
1322 king = flags & F_WHITE_ON_MOVE ? WhiteUnicorn : BlackUnicorn;
1323 if(gameInfo.variant == VariantChu) { // strictly speaking this is not needed, as Chu officially has no check
1324 int r, f, k = king, royals=0, prince = flags & F_WHITE_ON_MOVE ? WhiteMonarch : BlackMonarch;
1325 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++) {
1326 if(board[r][f] == k || board[r][f] == prince) {
1327 if(++royals > 1) return FALSE; // no check if we have two royals (ignores double captureby Lion!)
1328 king = board[r][f]; // remember hich one we had
1335 captured = board[rf][ft];
1336 board[rf][ft] = EmptySquare;
1338 captured = board[rt][ft];
1339 if(killX >= 0) { trampled = board[killY][killX]; board[killY][killX] = EmptySquare; }
1341 if(rf == DROP_RANK) board[rt][ft] = ff; else { // [HGM] drop
1342 board[rt][ft] = board[rf][ff];
1343 board[rf][ff] = EmptySquare;
1345 ep = board[EP_STATUS];
1346 if( captured == WhiteLion || captured == BlackLion ) { // [HGM] lion: Chu Lion-capture rules
1347 ChessSquare victim = killX < 0 ? EmptySquare : trampled;
1348 if( (board[rt][ft] == WhiteLion || board[rt][ft] == BlackLion) && // capturer is Lion
1349 (ff - ft > 1 || ft - ff > 1 || rf - rt > 1 || rt - rf > 1) && // captures from a distance
1350 (victim == EmptySquare || victim == WhitePawn || victim == BlackPawn) ) // no or worthless 'bridge'
1351 board[EP_STATUS] = EP_ROYAL_LION; // on distant Lion x Lion victim must not be pseudo-legally protected
1355 /* For compatibility with ICS wild 9, we scan the board in the
1356 order a1, a2, a3, ... b1, b2, ..., h8 to find the first king,
1357 and we test only whether that one is in check. */
1358 for (cl.fking = BOARD_LEFT+0; cl.fking < BOARD_RGHT; cl.fking++)
1359 for (cl.rking = 0; cl.rking < BOARD_HEIGHT; cl.rking++) {
1360 if (board[cl.rking][cl.fking] == king) {
1362 if(gameInfo.variant == VariantXiangqi) {
1363 /* [HGM] In Xiangqi opposing Kings means check as well */
1365 dir = (king >= BlackPawn) ? -1 : 1;
1366 for( i=cl.rking+dir; i>=0 && i<BOARD_HEIGHT &&
1367 board[i][cl.fking] == EmptySquare; i+=dir );
1368 if(i>=0 && i<BOARD_HEIGHT &&
1369 board[i][cl.fking] == (dir>0 ? BlackWazir : WhiteWazir) )
1372 GenPseudoLegal(board, flags ^ F_WHITE_ON_MOVE, CheckTestCallback, (VOIDSTAR) &cl, EmptySquare);
1373 if(gameInfo.variant != VariantSpartan || cl.check == 0) // in Spartan Chess go on to test if other King is checked too
1374 goto undo_move; /* 2-level break */
1381 if(rf != DROP_RANK) // [HGM] drop
1382 board[rf][ff] = board[rt][ft];
1384 board[rf][ft] = captured;
1385 board[rt][ft] = EmptySquare;
1387 if(killX >= 0) board[killY][killX] = trampled;
1388 board[rt][ft] = captured;
1390 board[EP_STATUS] = ep;
1393 return cl.fking < BOARD_RGHT ? cl.check : 1000; // [HGM] atomic: return 1000 if we have no king
1397 HasLion (Board board, int flags)
1399 int lion = F_WHITE_ON_MOVE & flags ? WhiteLion : BlackLion;
1401 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++)
1402 if(board[r][f] == lion) return 1;
1407 LegalDrop (Board board, int flags, ChessSquare piece, int rt, int ft)
1408 { // [HGM] put drop legality testing in separate routine for clarity
1410 if(appData.debugMode) fprintf(debugFP, "LegalDrop: %d @ %d,%d)\n", piece, ft, rt);
1411 if(board[rt][ft] != EmptySquare) return ImpossibleMove; // must drop to empty square
1412 n = PieceToNumber(piece);
1413 if((gameInfo.holdingsWidth == 0 || (flags & F_WHITE_ON_MOVE ? board[n][BOARD_WIDTH-1] : board[BOARD_HEIGHT-1-n][0]) != piece)
1414 && gameInfo.variant != VariantBughouse) // in bughouse we don't check for availability, because ICS doesn't always tell us
1415 return ImpossibleMove; // piece not available
1416 if(gameInfo.variant == VariantShogi) { // in Shogi lots of drops are forbidden!
1417 if((piece == WhitePawn || piece == WhiteQueen) && rt == BOARD_HEIGHT-1 ||
1418 (piece == BlackPawn || piece == BlackQueen) && rt == 0 ||
1419 piece == WhiteKnight && rt > BOARD_HEIGHT-3 ||
1420 piece == BlackKnight && rt < 2 ) return IllegalMove; // e.g. where dropped piece has no moves
1421 if(piece == WhitePawn || piece == BlackPawn) {
1423 for(r=1; r<BOARD_HEIGHT-1; r++)
1424 if(board[r][ft] == piece) return IllegalMove; // or there already is a Pawn in file
1425 // should still test if we mate with this Pawn
1427 } else if(gameInfo.variant == VariantSChess) { // only back-rank drops
1428 if (rt != (piece < BlackPawn ? 0 : BOARD_HEIGHT-1)) return IllegalMove;
1430 if( (piece == WhitePawn || piece == BlackPawn) &&
1431 (rt == 0 || rt == BOARD_HEIGHT -1 ) )
1432 return IllegalMove; /* no pawn drops on 1st/8th */
1434 if(appData.debugMode) fprintf(debugFP, "LegalDrop: %d @ %d,%d)\n", piece, ft, rt);
1435 if (!(flags & F_IGNORE_CHECK) &&
1436 CheckTest(board, flags, DROP_RANK, piece, rt, ft, FALSE) ) return IllegalMove;
1437 return flags & F_WHITE_ON_MOVE ? WhiteDrop : BlackDrop;
1440 extern void LegalityTestCallback P((Board board, int flags, ChessMove kind,
1441 int rf, int ff, int rt, int ft,
1445 LegalityTestCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1447 register LegalityTestClosure *cl = (LegalityTestClosure *) closure;
1449 if(board[rt][ft] != EmptySquare || kind==WhiteCapturesEnPassant || kind==BlackCapturesEnPassant)
1450 cl->captures++; // [HGM] losers: count legal captures
1451 if (rf == cl->rf && ff == cl->ff && rt == cl->rt && ft == cl->ft)
1456 LegalityTest (Board board, int flags, int rf, int ff, int rt, int ft, int promoChar)
1458 LegalityTestClosure cl; ChessSquare piece, filterPiece;
1460 if(quickFlag) flags = flags & ~1 | quickFlag & 1; // [HGM] speed: in quick mode quickFlag specifies side-to-move.
1461 if(rf == DROP_RANK) return LegalDrop(board, flags, ff, rt, ft);
1462 piece = filterPiece = board[rf][ff];
1463 if(PieceToChar(piece) == '~') filterPiece = DEMOTED piece;
1465 /* [HGM] Cobra and Falcon are wildcard pieces; consider all their moves legal */
1466 /* (perhaps we should disallow moves that obviously leave us in check?) */
1467 if((piece == WhiteFalcon || piece == BlackFalcon ||
1468 piece == WhiteCobra || piece == BlackCobra) && gameInfo.variant != VariantChu)
1469 return CheckTest(board, flags, rf, ff, rt, ft, FALSE) ? IllegalMove : NormalMove;
1473 cl.rt = rFilter = rt; // [HGM] speed: filter on to-square
1474 cl.ft = fFilter = ft;
1475 cl.kind = IllegalMove;
1476 cl.captures = 0; // [HGM] losers: prepare to count legal captures.
1477 if(flags & F_MANDATORY_CAPTURE) filterPiece = EmptySquare; // [HGM] speed: do not filter in suicide, to find all captures
1478 GenLegal(board, flags, LegalityTestCallback, (VOIDSTAR) &cl, filterPiece);
1479 if((flags & F_MANDATORY_CAPTURE) && cl.captures && board[rt][ft] == EmptySquare
1480 && cl.kind != WhiteCapturesEnPassant && cl.kind != BlackCapturesEnPassant)
1481 return(IllegalMove); // [HGM] losers: if there are legal captures, non-capts are illegal
1483 if(promoChar == 'x') promoChar = NULLCHAR; // [HGM] is this ever the case?
1484 if(gameInfo.variant == VariantSChess && promoChar && promoChar != '=' && board[rf][ff] != WhitePawn && board[rf][ff] != BlackPawn) {
1485 if(board[rf][ff] < BlackPawn) { // white
1486 if(rf != 0) return IllegalMove; // must be on back rank
1487 if(!(board[VIRGIN][ff] & VIRGIN_W)) return IllegalMove; // non-virgin
1488 if(board[PieceToNumber(CharToPiece(ToUpper(promoChar)))][BOARD_WIDTH-2] == 0) return ImpossibleMove;// must be in stock
1489 if(cl.kind == WhiteHSideCastleFR && (ff == BOARD_RGHT-2 || ff == BOARD_RGHT-3)) return ImpossibleMove;
1490 if(cl.kind == WhiteASideCastleFR && (ff == BOARD_LEFT+2 || ff == BOARD_LEFT+3)) return ImpossibleMove;
1492 if(rf != BOARD_HEIGHT-1) return IllegalMove;
1493 if(!(board[VIRGIN][ff] & VIRGIN_B)) return IllegalMove; // non-virgin
1494 if(board[BOARD_HEIGHT-1-PieceToNumber(CharToPiece(ToLower(promoChar)))][1] == 0) return ImpossibleMove;
1495 if(cl.kind == BlackHSideCastleFR && (ff == BOARD_RGHT-2 || ff == BOARD_RGHT-3)) return ImpossibleMove;
1496 if(cl.kind == BlackASideCastleFR && (ff == BOARD_LEFT+2 || ff == BOARD_LEFT+3)) return ImpossibleMove;
1499 if(gameInfo.variant == VariantChu) {
1500 if(cl.kind != NormalMove || promoChar == NULLCHAR || promoChar == '=') return cl.kind;
1501 if(promoChar != '+')
1502 return CharToPiece(promoChar) == EmptySquare ? ImpossibleMove : IllegalMove;
1503 if(PieceToChar(CHUPROMOTED board[rf][ff]) != '+') return ImpossibleMove;
1504 return flags & F_WHITE_ON_MOVE ? WhitePromotion : BlackPromotion;
1506 if(gameInfo.variant == VariantShogi) {
1507 /* [HGM] Shogi promotions. '=' means defer */
1508 if(rf != DROP_RANK && cl.kind == NormalMove) {
1509 ChessSquare piece = board[rf][ff];
1511 if(promoChar == PieceToChar(BlackQueen)) promoChar = NULLCHAR; /* [HGM] Kludge */
1512 if(promoChar == 'd' && (piece == WhiteRook || piece == BlackRook) ||
1513 promoChar == 'h' && (piece == WhiteBishop || piece == BlackBishop) ||
1514 promoChar == 'g' && (piece <= WhiteFerz || piece <= BlackFerz && piece >= BlackPawn) )
1515 promoChar = '+'; // allowed ICS notations
1516 if(appData.debugMode)fprintf(debugFP,"SHOGI promoChar = %c\n", promoChar ? promoChar : '-');
1517 if(promoChar != NULLCHAR && promoChar != '+' && promoChar != '=')
1518 return CharToPiece(promoChar) == EmptySquare ? ImpossibleMove : IllegalMove;
1519 else if(flags & F_WHITE_ON_MOVE) {
1520 if( (int) piece < (int) WhiteWazir &&
1521 (rf >= BOARD_HEIGHT - BOARD_HEIGHT/3 || rt >= BOARD_HEIGHT - BOARD_HEIGHT/3) ) {
1522 if( (piece == WhitePawn || piece == WhiteQueen) && rt > BOARD_HEIGHT-2 ||
1523 piece == WhiteKnight && rt > BOARD_HEIGHT-3) /* promotion mandatory */
1524 cl.kind = promoChar == '=' ? IllegalMove : WhitePromotion;
1525 else /* promotion optional, default is defer */
1526 cl.kind = promoChar == '+' ? WhitePromotion : WhiteNonPromotion;
1527 } else cl.kind = promoChar == '+' ? IllegalMove : NormalMove;
1529 if( (int) piece < (int) BlackWazir && (rf < BOARD_HEIGHT/3 || rt < BOARD_HEIGHT/3) ) {
1530 if( (piece == BlackPawn || piece == BlackQueen) && rt < 1 ||
1531 piece == BlackKnight && rt < 2 ) /* promotion obligatory */
1532 cl.kind = promoChar == '=' ? IllegalMove : BlackPromotion;
1533 else /* promotion optional, default is defer */
1534 cl.kind = promoChar == '+' ? BlackPromotion : BlackNonPromotion;
1535 } else cl.kind = promoChar == '+' ? IllegalMove : NormalMove;
1539 if (promoChar != NULLCHAR) {
1540 if(cl.kind == NormalMove && promoChar == '+') { // allow shogi-style promotion is pieceToChar specifies them
1541 ChessSquare piece = board[rf][ff];
1542 if(piece < BlackPawn ? piece > WhiteMan : piece > BlackMan) return ImpossibleMove; // already promoted
1543 // should test if in zone, really
1544 if(gameInfo.variant == VariantChuChess && (piece == WhiteKnight || piece == BlackKnight) && HasLion(board, flags))
1546 if(PieceToChar(PROMOTED piece) == '+') return flags & F_WHITE_ON_MOVE ? WhitePromotion : BlackPromotion;
1548 if(promoChar == '=') cl.kind = IllegalMove; else // [HGM] shogi: no deferred promotion outside Shogi
1549 if (cl.kind == WhitePromotion || cl.kind == BlackPromotion) {
1550 ChessSquare piece = CharToPiece(flags & F_WHITE_ON_MOVE ? ToUpper(promoChar) : ToLower(promoChar));
1551 if(piece == EmptySquare)
1552 cl.kind = ImpossibleMove; // non-existing piece
1553 if(gameInfo.variant == VariantChuChess && promoChar == 'l' && HasLion(board, flags)) {
1554 cl.kind = IllegalMove; // no two Lions
1555 } else if(gameInfo.variant == VariantSpartan && cl.kind == BlackPromotion ) {
1556 if(promoChar != PieceToChar(BlackKing)) {
1557 if(CheckTest(board, flags, rf, ff, rt, ft, FALSE)) cl.kind = IllegalMove; // [HGM] spartan: only promotion to King was possible
1558 if(piece == BlackLance) cl.kind = ImpossibleMove;
1559 } else { // promotion to King allowed only if we do not have two yet
1560 int r, f, kings = 0;
1561 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++) kings += (board[r][f] == BlackKing);
1562 if(kings == 2) cl.kind = IllegalMove;
1564 } else if(piece == WhitePawn && rt == BOARD_HEIGHT-1 ||
1565 piece == BlackPawn && rt == 0) cl.kind = IllegalMove; // cannot stay Pawn on last rank in any variant
1566 else if((piece == WhiteUnicorn || piece == BlackUnicorn) && gameInfo.variant == VariantKnightmate)
1567 cl.kind = IllegalMove; // promotion to Royal Knight not allowed
1568 else if((piece == WhiteKing || piece == BlackKing) && gameInfo.variant != VariantSuicide && gameInfo.variant != VariantGiveaway)
1569 cl.kind = IllegalMove; // promotion to King usually not allowed
1571 cl.kind = IllegalMove;
1581 extern void MateTestCallback P((Board board, int flags, ChessMove kind,
1582 int rf, int ff, int rt, int ft,
1586 MateTestCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1588 register MateTestClosure *cl = (MateTestClosure *) closure;
1593 /* Return MT_NONE, MT_CHECK, MT_CHECKMATE, or MT_STALEMATE */
1595 MateTest (Board board, int flags)
1598 int inCheck, r, f, myPieces=0, hisPieces=0, nrKing=0;
1599 ChessSquare king = flags & F_WHITE_ON_MOVE ? WhiteKing : BlackKing;
1601 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++) {
1602 // [HGM] losers: Count pieces and kings, to detect other unorthodox winning conditions
1603 nrKing += (board[r][f] == king); // stm has king
1604 if( board[r][f] != EmptySquare ) {
1605 if((int)board[r][f] <= (int)king && (int)board[r][f] >= (int)king - (int)WhiteKing + (int)WhitePawn)
1610 switch(gameInfo.variant) { // [HGM] losers: extinction wins
1611 case VariantShatranj:
1612 if(hisPieces == 1) return myPieces > 1 ? MT_BARE : MT_DRAW;
1616 if(nrKing == 0) return MT_NOKING;
1619 if(myPieces == 1) return MT_BARE;
1622 inCheck = GenLegal(board, flags, MateTestCallback, (VOIDSTAR) &cl, EmptySquare);
1623 // [HGM] 3check: yet to do!
1625 return inCheck ? MT_CHECK : MT_NONE;
1627 if(gameInfo.holdingsWidth && gameInfo.variant != VariantSuper && gameInfo.variant != VariantGreat
1628 && gameInfo.variant != VariantSChess && gameInfo.variant != VariantGrand) { // drop game
1629 int r, f, n, holdings = flags & F_WHITE_ON_MOVE ? BOARD_WIDTH-1 : 0;
1630 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++) if(board[r][f] == EmptySquare) // all empty squares
1631 for(n=0; n<BOARD_HEIGHT; n++) // all pieces in hand
1632 if(board[n][holdings] != EmptySquare) {
1633 int moveType = LegalDrop(board, flags, board[n][holdings], r, f);
1634 if(moveType == WhiteDrop || moveType == BlackDrop) return (inCheck ? MT_CHECK : MT_NONE); // we have legal drop
1637 if(gameInfo.variant == VariantSuicide) // [HGM] losers: always stalemate, since no check, but result varies
1638 return myPieces == hisPieces ? MT_STALEMATE :
1639 myPieces > hisPieces ? MT_STAINMATE : MT_STEALMATE;
1640 else if(gameInfo.variant == VariantLosers) return inCheck ? MT_TRICKMATE : MT_STEALMATE;
1641 else if(gameInfo.variant == VariantGiveaway) return MT_STEALMATE; // no check exists, stalemated = win
1643 return inCheck ? MT_CHECKMATE
1644 : (gameInfo.variant == VariantXiangqi || gameInfo.variant == VariantShatranj || IS_SHOGI(gameInfo.variant)) ?
1645 MT_STAINMATE : MT_STALEMATE;
1650 extern void DisambiguateCallback P((Board board, int flags, ChessMove kind,
1651 int rf, int ff, int rt, int ft,
1655 DisambiguateCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1657 register DisambiguateClosure *cl = (DisambiguateClosure *) closure;
1658 int wildCard = FALSE; ChessSquare piece = board[rf][ff];
1660 // [HGM] wild: for wild-card pieces rt and rf are dummies
1661 if(piece == WhiteFalcon || piece == BlackFalcon ||
1662 piece == WhiteCobra || piece == BlackCobra)
1665 if ((cl->pieceIn == EmptySquare || cl->pieceIn == board[rf][ff]
1666 || PieceToChar(board[rf][ff]) == '~'
1667 && cl->pieceIn == (ChessSquare)(DEMOTED board[rf][ff])
1669 (cl->rfIn == -1 || cl->rfIn == rf) &&
1670 (cl->ffIn == -1 || cl->ffIn == ff) &&
1671 (cl->rtIn == -1 || cl->rtIn == rt || wildCard) &&
1672 (cl->ftIn == -1 || cl->ftIn == ft || wildCard)) {
1675 if(cl->count == 1 || board[rt][ft] != EmptySquare) {
1676 // [HGM] oneclick: if multiple moves, be sure we remember capture
1677 cl->piece = board[rf][ff];
1680 cl->rt = wildCard ? cl->rtIn : rt;
1681 cl->ft = wildCard ? cl->ftIn : ft;
1684 cl->captures += (board[rt][ft] != EmptySquare); // [HGM] oneclick: count captures
1689 Disambiguate (Board board, int flags, DisambiguateClosure *closure)
1691 int illegal = 0; char c = closure->promoCharIn;
1693 if(quickFlag) flags = flags & ~1 | quickFlag & 1; // [HGM] speed: in quick mode quickFlag specifies side-to-move.
1694 closure->count = closure->captures = 0;
1695 closure->rf = closure->ff = closure->rt = closure->ft = 0;
1696 closure->kind = ImpossibleMove;
1697 rFilter = closure->rtIn; // [HGM] speed: only consider moves to given to-square
1698 fFilter = closure->ftIn;
1699 if(quickFlag) { // [HGM] speed: try without check test first, because if that is not ambiguous, we are happy
1700 GenLegal(board, flags|F_IGNORE_CHECK, DisambiguateCallback, (VOIDSTAR) closure, closure->pieceIn);
1701 if(closure->count > 1) { // gamble did not pay off. retry with check test to resolve ambiguity
1702 closure->count = closure->captures = 0;
1703 closure->rf = closure->ff = closure->rt = closure->ft = 0;
1704 closure->kind = ImpossibleMove;
1705 GenLegal(board, flags, DisambiguateCallback, (VOIDSTAR) closure, closure->pieceIn); // [HGM] speed: only pieces of requested type
1708 GenLegal(board, flags, DisambiguateCallback, (VOIDSTAR) closure, closure->pieceIn); // [HGM] speed: only pieces of requested type
1709 if (closure->count == 0) {
1710 /* See if it's an illegal move due to check */
1712 GenLegal(board, flags|F_IGNORE_CHECK, DisambiguateCallback, (VOIDSTAR) closure, closure->pieceIn);
1713 if (closure->count == 0) {
1714 /* No, it's not even that */
1715 if(!appData.testLegality && closure->pieceIn != EmptySquare) {
1716 int f, r; // if there is only a single piece of the requested type on the board, use that
1717 closure->rt = closure->rtIn, closure->ft = closure->ftIn;
1718 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++)
1719 if(board[r][f] == closure->pieceIn) closure->count++, closure->rf = r, closure->ff = f;
1720 if(closure->count > 1) illegal = 0; // ambiguous
1722 if(closure->count == 0) {
1723 if (appData.debugMode) { int i, j;
1724 for(i=BOARD_HEIGHT-1; i>=0; i--) {
1725 for(j=0; j<BOARD_WIDTH; j++)
1726 fprintf(debugFP, "%3d", (int) board[i][j]);
1727 fprintf(debugFP, "\n");
1735 if (c == 'x') c = NULLCHAR; // get rid of any 'x' (which should never happen?)
1736 if(gameInfo.variant == VariantSChess && c && c != '=' && closure->piece != WhitePawn && closure->piece != BlackPawn) {
1737 if(closure->piece < BlackPawn) { // white
1738 if(closure->rf != 0) closure->kind = IllegalMove; // must be on back rank
1739 if(!(board[VIRGIN][closure->ff] & VIRGIN_W)) closure->kind = IllegalMove; // non-virgin
1740 if(board[PieceToNumber(CharToPiece(ToUpper(c)))][BOARD_WIDTH-2] == 0) closure->kind = ImpossibleMove;// must be in stock
1741 if(closure->kind == WhiteHSideCastleFR && (closure->ff == BOARD_RGHT-2 || closure->ff == BOARD_RGHT-3)) closure->kind = ImpossibleMove;
1742 if(closure->kind == WhiteASideCastleFR && (closure->ff == BOARD_LEFT+2 || closure->ff == BOARD_LEFT+3)) closure->kind = ImpossibleMove;
1744 if(closure->rf != BOARD_HEIGHT-1) closure->kind = IllegalMove;
1745 if(!(board[VIRGIN][closure->ff] & VIRGIN_B)) closure->kind = IllegalMove; // non-virgin
1746 if(board[BOARD_HEIGHT-1-PieceToNumber(CharToPiece(ToLower(c)))][1] == 0) closure->kind = ImpossibleMove;
1747 if(closure->kind == BlackHSideCastleFR && (closure->ff == BOARD_RGHT-2 || closure->ff == BOARD_RGHT-3)) closure->kind = ImpossibleMove;
1748 if(closure->kind == BlackASideCastleFR && (closure->ff == BOARD_LEFT+2 || closure->ff == BOARD_LEFT+3)) closure->kind = ImpossibleMove;
1751 if(gameInfo.variant == VariantChu) {
1752 if(c == '+') closure->kind = (flags & F_WHITE_ON_MOVE ? WhitePromotion : BlackPromotion); // for now, accept any
1754 if(gameInfo.variant == VariantShogi) {
1755 /* [HGM] Shogi promotions. On input, '=' means defer, '+' promote. Afterwards, c is set to '+' for promotions, NULL other */
1756 if(closure->rfIn != DROP_RANK && closure->kind == NormalMove) {
1757 ChessSquare piece = closure->piece;
1758 if (c == 'd' && (piece == WhiteRook || piece == BlackRook) ||
1759 c == 'h' && (piece == WhiteBishop || piece == BlackBishop) ||
1760 c == 'g' && (piece <= WhiteFerz || piece <= BlackFerz && piece >= BlackPawn) )
1761 c = '+'; // allowed ICS notations
1762 if(c != NULLCHAR && c != '+' && c != '=') closure->kind = IllegalMove; // otherwise specifying a piece is illegal
1763 else if(flags & F_WHITE_ON_MOVE) {
1764 if( (int) piece < (int) WhiteWazir &&
1765 (closure->rf >= BOARD_HEIGHT-(BOARD_HEIGHT/3) || closure->rt >= BOARD_HEIGHT-(BOARD_HEIGHT/3)) ) {
1766 if( (piece == WhitePawn || piece == WhiteQueen) && closure->rt > BOARD_HEIGHT-2 ||
1767 piece == WhiteKnight && closure->rt > BOARD_HEIGHT-3) /* promotion mandatory */
1768 closure->kind = c == '=' ? IllegalMove : WhitePromotion;
1769 else /* promotion optional, default is defer */
1770 closure->kind = c == '+' ? WhitePromotion : WhiteNonPromotion;
1771 } else closure->kind = c == '+' ? IllegalMove : NormalMove;
1773 if( (int) piece < (int) BlackWazir && (closure->rf < BOARD_HEIGHT/3 || closure->rt < BOARD_HEIGHT/3) ) {
1774 if( (piece == BlackPawn || piece == BlackQueen) && closure->rt < 1 ||
1775 piece == BlackKnight && closure->rt < 2 ) /* promotion obligatory */
1776 closure->kind = c == '=' ? IllegalMove : BlackPromotion;
1777 else /* promotion optional, default is defer */
1778 closure->kind = c == '+' ? BlackPromotion : BlackNonPromotion;
1779 } else closure->kind = c == '+' ? IllegalMove : NormalMove;
1782 if(closure->kind == WhitePromotion || closure->kind == BlackPromotion) c = '+'; else
1783 if(closure->kind == WhiteNonPromotion || closure->kind == BlackNonPromotion) c = '=';
1785 if (closure->kind == WhitePromotion || closure->kind == BlackPromotion) {
1786 if(c == NULLCHAR) { // missing promoChar on mandatory promotion; use default for variant
1787 if(gameInfo.variant == VariantShatranj || gameInfo.variant == VariantCourier ||
1788 gameInfo.variant == VariantMakruk || gameInfo.variant == VariantASEAN)
1789 c = PieceToChar(BlackFerz);
1790 else if(gameInfo.variant == VariantGreat)
1791 c = PieceToChar(BlackMan);
1792 else if(gameInfo.variant == VariantGrand)
1793 closure->kind = closure->rt != 0 && closure->rt != BOARD_HEIGHT-1 ? NormalMove : AmbiguousMove; // no default in Grand Chess
1795 c = PieceToChar(BlackQueen);
1796 } else if(c == '=') closure->kind = IllegalMove; // no deferral outside Shogi
1797 else if(c == 'l' && gameInfo.variant == VariantChuChess && HasLion(board, flags)) closure->kind = IllegalMove;
1798 } else if (c == '+') { // '+' outside shogi, check if pieceToCharTable enabled it
1799 ChessSquare p = closure->piece;
1800 if(p > WhiteMan && p < BlackPawn || p > BlackMan || PieceToChar(PROMOTED p) != '+')
1801 closure->kind = ImpossibleMove; // used on non-promotable piece
1802 else if(gameInfo.variant == VariantChuChess && HasLion(board, flags)) closure->kind = IllegalMove;
1803 } else if (c != NULLCHAR) closure->kind = IllegalMove;
1805 closure->promoChar = ToLower(c); // this can be NULLCHAR! Note we keep original promoChar even if illegal.
1806 if(c != '+' && c != '=' && c != NULLCHAR && CharToPiece(flags & F_WHITE_ON_MOVE ? ToUpper(c) : ToLower(c)) == EmptySquare)
1807 closure->kind = ImpossibleMove; // but we cannot handle non-existing piece types!
1808 if (closure->count > 1) {
1809 closure->kind = AmbiguousMove;
1812 /* Note: If more than one illegal move matches, but no legal
1813 moves, we return IllegalMove, not AmbiguousMove. Caller
1814 can look at closure->count to detect this.
1816 closure->kind = IllegalMove;
1830 } CoordsToAlgebraicClosure;
1832 extern void CoordsToAlgebraicCallback P((Board board, int flags,
1833 ChessMove kind, int rf, int ff,
1834 int rt, int ft, VOIDSTAR closure));
1837 CoordsToAlgebraicCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1839 register CoordsToAlgebraicClosure *cl =
1840 (CoordsToAlgebraicClosure *) closure;
1842 if ((rt == cl->rt && ft == cl->ft || rt == rf && ft == ff) && // [HGM] null move matches any toSquare
1843 (board[rf][ff] == cl->piece
1844 || PieceToChar(board[rf][ff]) == '~' &&
1845 (ChessSquare) (DEMOTED board[rf][ff]) == cl->piece)
1849 cl->kind = kind; /* this is the move we want */
1851 cl->file++; /* need file to rule out this move */
1855 cl->rank++; /* need rank to rule out this move */
1857 cl->either++; /* rank or file will rule out this move */
1863 /* Convert coordinates to normal algebraic notation.
1864 promoChar must be NULLCHAR or 'x' if not a promotion.
1867 CoordsToAlgebraic (Board board, int flags, int rf, int ff, int rt, int ft, int promoChar, char out[MOVE_LEN])
1871 char *outp = out, c;
1872 CoordsToAlgebraicClosure cl;
1874 if (rf == DROP_RANK) {
1875 if(ff == EmptySquare) { strncpy(outp, "--",3); return NormalMove; } // [HGM] pass
1876 /* Bughouse piece drop */
1877 *outp++ = ToUpper(PieceToChar((ChessSquare) ff));
1882 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
1884 return (flags & F_WHITE_ON_MOVE) ? WhiteDrop : BlackDrop;
1887 if (promoChar == 'x') promoChar = NULLCHAR;
1888 piece = board[rf][ff];
1889 if(PieceToChar(piece)=='~') piece = (ChessSquare)(DEMOTED piece);
1894 kind = LegalityTest(board, flags, rf, ff, rt, ft, promoChar);
1895 if (kind == IllegalMove && !(flags&F_IGNORE_CHECK)) {
1896 /* Keep short notation if move is illegal only because it
1897 leaves the player in check, but still return IllegalMove */
1898 kind = LegalityTest(board, flags|F_IGNORE_CHECK, rf, ff, rt, ft, promoChar);
1899 if (kind == IllegalMove) break;
1904 if (ff == ft && board[rt][ft] == EmptySquare) { /* [HGM] Xiangqi has straight noncapts! */
1905 /* Non-capture; use style "e5" */
1908 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
1910 /* Capture; use style "exd5" */
1911 if(gameInfo.variant != VariantXiangqi || board[rt][ft] != EmptySquare )
1912 *outp++ = 'x'; /* [HGM] Xiangqi has sideway noncaptures across river! */
1916 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
1918 /* Use promotion suffix style "=Q" */
1920 if (promoChar != NULLCHAR) {
1921 if(IS_SHOGI(gameInfo.variant)) {
1922 /* [HGM] ... but not in Shogi! */
1923 *outp++ = promoChar == '=' ? '=' : '+';
1926 *outp++ = ToUpper(promoChar);
1935 /* Fabien moved code: FRC castling first (if KxR), wild castling second */
1936 /* Code added by Tord: FRC castling. */
1937 if((piece == WhiteKing && board[rt][ft] == WhiteRook) ||
1938 (piece == BlackKing && board[rt][ft] == BlackRook)) {
1940 safeStrCpy(out, "O-O", MOVE_LEN);
1942 safeStrCpy(out, "O-O-O", MOVE_LEN);
1943 return LegalityTest(board, flags, rf, ff, rt, ft, promoChar);
1945 /* End of code added by Tord */
1946 /* Test for castling or ICS wild castling */
1947 /* Use style "O-O" (oh-oh) for PGN compatibility */
1948 else if (rf == rt &&
1949 rf == ((piece == WhiteKing) ? 0 : BOARD_HEIGHT-1) &&
1950 (ft - ff > 1 || ff - ft > 1) && // No castling if legal King move (on narrow boards!)
1951 ((ff == BOARD_WIDTH>>1 && (ft == BOARD_LEFT+2 || ft == BOARD_RGHT-2)) ||
1952 (ff == (BOARD_WIDTH-1)>>1 && (ft == BOARD_LEFT+1 || ft == BOARD_RGHT-3)))) {
1953 if(ft==BOARD_LEFT+1 || ft==BOARD_RGHT-2)
1954 snprintf(out, MOVE_LEN, "O-O%c%c", promoChar ? '/' : 0, ToUpper(promoChar));
1956 snprintf(out, MOVE_LEN, "O-O-O%c%c", promoChar ? '/' : 0, ToUpper(promoChar));
1958 /* This notation is always unambiguous, unless there are
1959 kings on both the d and e files, with "wild castling"
1960 possible for the king on the d file and normal castling
1961 possible for the other. ICS rules for wild 9
1962 effectively make castling illegal for either king in
1963 this situation. So I am not going to worry about it;
1964 I'll just generate an ambiguous O-O in this case.
1966 return LegalityTest(board, flags, rf, ff, rt, ft, promoChar);
1969 /* else fall through */
1974 cl.rt = rFilter = rt; // [HGM] speed: filter on to-square
1975 cl.ft = fFilter = ft;
1977 cl.kind = IllegalMove;
1978 cl.rank = cl.file = cl.either = 0;
1979 c = PieceToChar(piece) ;
1980 GenLegal(board, flags, CoordsToAlgebraicCallback, (VOIDSTAR) &cl, c!='~' ? piece : (DEMOTED piece)); // [HGM] speed
1982 if (cl.kind == IllegalMove && !(flags&F_IGNORE_CHECK)) {
1983 /* Generate pretty moves for moving into check, but
1984 still return IllegalMove.
1986 GenLegal(board, flags|F_IGNORE_CHECK, CoordsToAlgebraicCallback, (VOIDSTAR) &cl, c!='~' ? piece : (DEMOTED piece));
1987 if (cl.kind == IllegalMove) break;
1988 cl.kind = IllegalMove;
1991 /* Style is "Nf3" or "Nxf7" if this is unambiguous,
1992 else "Ngf3" or "Ngxf7",
1993 else "N1f3" or "N5xf7",
1994 else "Ng1f3" or "Ng5xf7".
1996 if( c == '~' || c == '+') {
1997 /* [HGM] print nonexistent piece as its demoted version */
1998 piece = (ChessSquare) (DEMOTED piece - 11*(gameInfo.variant == VariantChu));
2000 if(c=='+') *outp++ = c;
2001 *outp++ = ToUpper(PieceToChar(piece));
2003 if (cl.file || (cl.either && !cl.rank)) {
2009 else { *outp++ = (rf+ONE-'0')/10 + '0';*outp++ = (rf+ONE-'0')%10 + '0'; }
2012 if(board[rt][ft] != EmptySquare)
2018 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2019 if (IS_SHOGI(gameInfo.variant)) {
2020 /* [HGM] in Shogi non-pawns can promote */
2021 *outp++ = promoChar; // Don't bother to correct move type, return value is never used!
2023 else if (gameInfo.variant == VariantChuChess && promoChar ||
2024 gameInfo.variant != VariantSuper && promoChar &&
2025 (piece == WhiteLance || piece == BlackLance) ) { // Lance sometimes represents Pawn
2027 *outp++ = ToUpper(promoChar);
2029 else if (gameInfo.variant == VariantSChess && promoChar) { // and in S-Chess we have gating
2031 *outp++ = ToUpper(promoChar);
2037 /* Moving a nonexistent piece */
2041 /* Not a legal move, even ignoring check.
2042 If there was a piece on the from square,
2043 use style "Ng1g3" or "Ng1xe8";
2044 if there was a pawn or nothing (!),
2045 use style "g1g3" or "g1xe8". Use "x"
2046 if a piece was on the to square, even
2047 a piece of the same color.
2051 if (piece != EmptySquare && piece != WhitePawn && piece != BlackPawn) {
2053 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<=BOARD_RGHT; f++)
2054 c += (board[r][f] == piece); // count on-board pieces of given type
2055 *outp++ = ToUpper(PieceToChar(piece));
2057 if(c != 1) { // [HGM] but if there is only one piece of the mentioned type, no from-square, thank you!
2061 else { *outp++ = (rf+ONE-'0')/10 + '0';*outp++ = (rf+ONE-'0')%10 + '0'; }
2063 if (board[rt][ft] != EmptySquare) *outp++ = 'x';
2067 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2068 /* Use promotion suffix style "=Q" */
2069 if (promoChar != NULLCHAR && promoChar != 'x') {
2071 *outp++ = ToUpper(promoChar);
2078 // [HGM] XQ: the following code serves to detect perpetual chasing (Asian rules)
2087 // I guess the following variables logically belong in the closure too, but I was too lazy and used globals
2089 int preyStackPointer, chaseStackPointer;
2092 unsigned char rf, ff, rt, ft;
2096 unsigned char rank, file;
2102 // there are three new callbacks for use with GenLegal: for adding captures, deleting them, and finding a recapture
2104 extern void AtacksCallback P((Board board, int flags, ChessMove kind,
2105 int rf, int ff, int rt, int ft,
2109 AttacksCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
2110 { // For adding captures that can lead to chase indictment to the chaseStack
2111 if(board[rt][ft] == EmptySquare) return; // non-capture
2112 if(board[rt][ft] == WhitePawn && rt < BOARD_HEIGHT/2) return; // Pawn before river can be chased
2113 if(board[rt][ft] == BlackPawn && rt >= BOARD_HEIGHT/2) return; // Pawn before river can be chased
2114 if(board[rf][ff] == WhitePawn || board[rf][ff] == BlackPawn) return; // Pawns are allowed to chase
2115 if(board[rf][ff] == WhiteWazir || board[rf][ff] == BlackWazir) return; // King is allowed to chase
2116 // move cannot be excluded from being a chase trivially (based on attacker and victim); save it on chaseStack
2117 chaseStack[chaseStackPointer].rf = rf;
2118 chaseStack[chaseStackPointer].ff = ff;
2119 chaseStack[chaseStackPointer].rt = rt;
2120 chaseStack[chaseStackPointer].ft = ft;
2121 chaseStackPointer++;
2124 extern void ExistingAtacksCallback P((Board board, int flags, ChessMove kind,
2125 int rf, int ff, int rt, int ft,
2129 ExistingAttacksCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
2130 { // for removing pre-exsting captures from the chaseStack, to be left with newly created ones
2132 register ChaseClosure *cl = (ChaseClosure *) closure; //closure tells us the move played in the repeat loop
2134 if(board[rt][ft] == EmptySquare) return; // no capture
2135 if(rf == cl->rf && ff == cl->ff) { // attacks with same piece from new position are not considered new
2136 rf = cl->rt; ff = cl->ft; // doctor their fromSquare so they will be recognized in chaseStack
2138 // search move in chaseStack, and delete it if it occurred there (as we know now it is not a new capture)
2139 for(i=0; i<chaseStackPointer; i++) {
2140 if(chaseStack[i].rf == rf && chaseStack[i].ff == ff &&
2141 chaseStack[i].rt == rt && chaseStack[i].ft == ft ) {
2142 // move found on chaseStack, delete it by overwriting with move popped from top of chaseStack
2143 chaseStack[i] = chaseStack[--chaseStackPointer];
2149 extern void ProtectedCallback P((Board board, int flags, ChessMove kind,
2150 int rf, int ff, int rt, int ft,
2154 ProtectedCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
2155 { // for determining if a piece (given through the closure) is protected
2156 register ChaseClosure *cl = (ChaseClosure *) closure; // closure tells us where to recapture
2158 if(rt == cl->rt && ft == cl->ft) cl->recaptures++; // count legal recaptures to this square
2159 if(appData.debugMode && board[rt][ft] != EmptySquare)
2160 fprintf(debugFP, "try %c%c%c%c=%d\n", ff+AAA, rf+ONE,ft+AAA, rt+ONE, cl->recaptures);
2163 extern char moveList[MAX_MOVES][MOVE_LEN];
2166 PerpetualChase (int first, int last)
2167 { // this routine detects if the side to move in the 'first' position is perpetually chasing (when not checking)
2170 ChessSquare captured;
2172 preyStackPointer = 0; // clear stack of chased pieces
2173 for(i=first; i<last; i+=2) { // for all positions with same side to move
2174 if(appData.debugMode) fprintf(debugFP, "judge position %i\n", i);
2175 chaseStackPointer = 0; // clear stack that is going to hold possible chases
2176 // determine all captures possible after the move, and put them on chaseStack
2177 GenLegal(boards[i+1], PosFlags(i), AttacksCallback, &cl, EmptySquare);
2178 if(appData.debugMode) { int n;
2179 for(n=0; n<chaseStackPointer; n++)
2180 fprintf(debugFP, "%c%c%c%c ", chaseStack[n].ff+AAA, chaseStack[n].rf+ONE,
2181 chaseStack[n].ft+AAA, chaseStack[n].rt+ONE);
2182 fprintf(debugFP, ": all capts\n");
2184 // determine all captures possible before the move, and delete them from chaseStack
2185 cl.rf = moveList[i][1]-ONE; // prepare closure to pass move that led from i to i+1
2186 cl.ff = moveList[i][0]-AAA+BOARD_LEFT;
2187 cl.rt = moveList[i][3]-ONE;
2188 cl.ft = moveList[i][2]-AAA+BOARD_LEFT;
2189 CopyBoard(xqCheckers, nullBoard); xqCheckers[EP_STATUS] = 1; // giant kludge to make GenLegal ignore pre-existing checks
2190 GenLegal(boards[i], PosFlags(i), ExistingAttacksCallback, &cl, EmptySquare);
2191 xqCheckers[EP_STATUS] = 0; // disable the generation of quasi-legal moves again
2192 if(appData.debugMode) { int n;
2193 for(n=0; n<chaseStackPointer; n++)
2194 fprintf(debugFP, "%c%c%c%c ", chaseStack[n].ff+AAA, chaseStack[n].rf+ONE,
2195 chaseStack[n].ft+AAA, chaseStack[n].rt+ONE);
2196 fprintf(debugFP, ": new capts after %c%c%c%c\n", cl.ff+AAA, cl.rf+ONE, cl.ft+AAA, cl.rt+ONE);
2198 // chaseSack now contains all captures made possible by the move
2199 for(j=0; j<chaseStackPointer; j++) { // run through chaseStack to identify true chases
2200 int attacker = (int)boards[i+1][chaseStack[j].rf][chaseStack[j].ff];
2201 int victim = (int)boards[i+1][chaseStack[j].rt][chaseStack[j].ft];
2203 if(attacker >= (int) BlackPawn) attacker = BLACK_TO_WHITE attacker; // convert to white, as piecee type
2204 if(victim >= (int) BlackPawn) victim = BLACK_TO_WHITE victim;
2206 if((attacker == WhiteKnight || attacker == WhiteCannon) && victim == WhiteRook)
2207 continue; // C or H attack on R is always chase; leave on chaseStack
2209 if(attacker == victim) {
2210 if(LegalityTest(boards[i+1], PosFlags(i+1), chaseStack[j].rt,
2211 chaseStack[j].ft, chaseStack[j].rf, chaseStack[j].ff, NULLCHAR) == NormalMove) {
2212 // we can capture back with equal piece, so this is no chase but a sacrifice
2213 chaseStack[j] = chaseStack[--chaseStackPointer]; // delete the capture from the chaseStack
2214 j--; /* ! */ continue;
2219 // the attack is on a lower piece, or on a pinned or blocked equal one
2220 CopyBoard(xqCheckers, nullBoard); xqCheckers[EP_STATUS] = 1;
2221 CheckTest(boards[i+1], PosFlags(i+1), -1, -1, -1, -1, FALSE); // if we deliver check with our move, the checkers get marked
2222 // test if the victim is protected by a true protector. First make the capture.
2223 captured = boards[i+1][chaseStack[j].rt][chaseStack[j].ft];
2224 boards[i+1][chaseStack[j].rt][chaseStack[j].ft] = boards[i+1][chaseStack[j].rf][chaseStack[j].ff];
2225 boards[i+1][chaseStack[j].rf][chaseStack[j].ff] = EmptySquare;
2226 // Then test if the opponent can recapture
2227 cl.recaptures = 0; // prepare closure to pass recapture square and count moves to it
2228 cl.rt = chaseStack[j].rt;
2229 cl.ft = chaseStack[j].ft;
2230 if(appData.debugMode) {
2231 fprintf(debugFP, "test if we can recapture %c%c\n", cl.ft+AAA, cl.rt+ONE);
2233 xqCheckers[EP_STATUS] = 2; // causes GenLegal to ignore the checks we delivered with the move, in real life evaded before we captured
2234 GenLegal(boards[i+1], PosFlags(i+1), ProtectedCallback, &cl, EmptySquare); // try all moves
2235 xqCheckers[EP_STATUS] = 0; // disable quasi-legal moves again
2236 // unmake the capture
2237 boards[i+1][chaseStack[j].rf][chaseStack[j].ff] = boards[i+1][chaseStack[j].rt][chaseStack[j].ft];
2238 boards[i+1][chaseStack[j].rt][chaseStack[j].ft] = captured;
2239 // if a recapture was found, piece is protected, and we are not chasing it.
2240 if(cl.recaptures) { // attacked piece was defended by true protector, no chase
2241 chaseStack[j] = chaseStack[--chaseStackPointer]; // so delete from chaseStack
2245 // chaseStack now contains all moves that chased
2246 if(appData.debugMode) { int n;
2247 for(n=0; n<chaseStackPointer; n++)
2248 fprintf(debugFP, "%c%c%c%c ", chaseStack[n].ff+AAA, chaseStack[n].rf+ONE,
2249 chaseStack[n].ft+AAA, chaseStack[n].rt+ONE);
2250 fprintf(debugFP, ": chases\n");
2252 if(i == first) { // copy all people chased by first move of repeat cycle to preyStack
2253 for(j=0; j<chaseStackPointer; j++) {
2254 preyStack[j].rank = chaseStack[j].rt;
2255 preyStack[j].file = chaseStack[j].ft;
2257 preyStackPointer = chaseStackPointer;
2260 for(j=0; j<chaseStackPointer; j++) {
2261 for(k=0; k<preyStackPointer; k++) {
2262 // search the victim of each chase move on the preyStack (first occurrence)
2263 if(chaseStack[j].ft == preyStack[k].file && chaseStack[j].rt == preyStack[k].rank ) {
2264 if(k < tail) break; // piece was already identified as still being chased
2265 preyStack[preyStackPointer] = preyStack[tail]; // move chased piece to bottom part of preyStack
2266 preyStack[tail] = preyStack[k]; // by swapping
2267 preyStack[k] = preyStack[preyStackPointer];
2273 preyStackPointer = tail; // keep bottom part of preyStack, popping pieces unchased on move i.
2274 if(appData.debugMode) { int n;
2275 for(n=0; n<preyStackPointer; n++)
2276 fprintf(debugFP, "%c%c ", preyStack[n].file+AAA, preyStack[n].rank+ONE);
2277 fprintf(debugFP, "always chased upto ply %d\n", i);
2279 // now adjust the location of the chased pieces according to opponent move
2280 for(j=0; j<preyStackPointer; j++) {
2281 if(preyStack[j].rank == moveList[i+1][1]-ONE &&
2282 preyStack[j].file == moveList[i+1][0]-AAA+BOARD_LEFT) {
2283 preyStack[j].rank = moveList[i+1][3]-ONE;
2284 preyStack[j].file = moveList[i+1][2]-AAA+BOARD_LEFT;
2289 return preyStackPointer ? 256*(preyStack[preyStackPointer].file - BOARD_LEFT + AAA) + (preyStack[preyStackPointer].rank + ONE)
2290 : 0; // if any piece was left on preyStack, it has been perpetually chased,and we return the