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. */
61 #else /* not HAVE_STRING_H */
63 #endif /* not HAVE_STRING_H */
69 int WhitePiece P((ChessSquare));
70 int BlackPiece P((ChessSquare));
71 int SameColor P((ChessSquare, ChessSquare));
72 int PosFlags(int index);
74 extern signed char initialRights[BOARD_FILES]; /* [HGM] all rights enabled, set in InitPosition */
76 char *pieceDesc[EmptySquare];
79 WhitePiece (ChessSquare piece)
81 return (int) piece >= (int) WhitePawn && (int) piece < (int) BlackPawn;
85 BlackPiece (ChessSquare piece)
87 return (int) piece >= (int) BlackPawn && (int) piece < (int) EmptySquare;
92 SameColor (ChessSquare piece1, ChessSquare piece2)
94 return ((int) piece1 >= (int) WhitePawn && /* [HGM] can be > King ! */
95 (int) piece1 < (int) BlackPawn &&
96 (int) piece2 >= (int) WhitePawn &&
97 (int) piece2 < (int) BlackPawn)
98 || ((int) piece1 >= (int) BlackPawn &&
99 (int) piece1 < (int) EmptySquare &&
100 (int) piece2 >= (int) BlackPawn &&
101 (int) piece2 < (int) EmptySquare);
104 #define SameColor(piece1, piece2) (piece1 < EmptySquare && piece2 < EmptySquare && (piece1 < BlackPawn) == (piece2 < BlackPawn) || piece1 == DarkSquare || piece2 == DarkSquare)
107 char pieceToChar[] = {
108 'P', 'N', 'B', 'R', 'Q', 'F', 'E', 'A', 'C', 'W', 'M',
109 'O', 'H', 'I', 'J', 'G', 'D', 'V', 'L', 'S', 'U', 'K',
110 'p', 'n', 'b', 'r', 'q', 'f', 'e', 'a', 'c', 'w', 'm',
111 'o', 'h', 'i', 'j', 'g', 'd', 'v', 'l', 's', 'u', 'k',
113 char pieceNickName[EmptySquare];
116 PieceToChar (ChessSquare p)
118 if((int)p < 0 || (int)p >= (int)EmptySquare) return('x'); /* [HGM] for safety */
119 return pieceToChar[(int) p];
123 PieceToNumber (ChessSquare p) /* [HGM] holdings: count piece type, ignoring non-participating piece types */
126 ChessSquare start = (int)p >= (int)BlackPawn ? BlackPawn : WhitePawn;
128 while(start++ != p) if(pieceToChar[(int)start-1] != '.') i++;
136 if(c == '.') return EmptySquare;
137 for(i=0; i< (int) EmptySquare; i++)
138 if(pieceNickName[i] == c) return (ChessSquare) i;
139 for(i=0; i< (int) EmptySquare; i++)
140 if(pieceToChar[i] == c) return (ChessSquare) i;
145 CopyBoard (Board to, Board from)
149 for (i = 0; i < BOARD_HEIGHT; i++)
150 for (j = 0; j < BOARD_WIDTH; j++)
151 to[i][j] = from[i][j];
152 for (j = 0; j < BOARD_FILES; j++) // [HGM] gamestate: copy castling rights and ep status
153 to[VIRGIN][j] = from[VIRGIN][j],
154 to[CASTLING][j] = from[CASTLING][j];
155 to[HOLDINGS_SET] = 0; // flag used in ICS play
159 CompareBoards (Board board1, Board board2)
163 for (i = 0; i < BOARD_HEIGHT; i++)
164 for (j = 0; j < BOARD_WIDTH; j++) {
165 if (board1[i][j] != board2[i][j])
171 // [HGM] gen: configurable move generation from Betza notation sent by engine.
173 // alphabet "abcdefghijklmnopqrstuvwxyz"
174 char symmetry[] = "FBNW.FFW.NKN.NW.QR....W..N";
175 char xStep[] = "2110.130.102.10.00....0..2";
176 char yStep[] = "2132.133.313.20.11....1..3";
177 char dirType[] = "01000104000200000260050000";
178 // alphabet "a b c d e f g h i j k l m n o p q r s t u v w x y z "
179 int dirs1[] = { 0,0x3C,0,0,0,0xC3,0,0, 0,0,0,0xF0,0,0,0,0,0,0x0F,0 ,0,0,0 ,0,0,0,0 };
180 int dirs2[] = { 0,0x18,0,0,0,0x81,0,0xFF,0,0,0,0x60,0,0,0,0,0,0x06,0x66,0,0,0x99,0,0,0,0 };
182 int rot[][4] = { // rotation matrices for each direction
194 MovesFromString (Board board, int flags, int f, int r, char *desc, MoveCallback cb, VOIDSTAR cl)
197 int mine, his, dir, bit, occup, i;
198 if(flags & F_WHITE_ON_MOVE) his = 2, mine = 1; else his = 1, mine = 2;
199 while(*p) { // more moves to go
200 int expo = 1, dx, dy, x, y, mode, dirSet, retry=0, initial=0, jump=1;
201 if(*p == 'i') initial = 1, desc = ++p;
202 while(islower(*p)) p++; // skip prefixes
203 if(!isupper(*p)) return; // syntax error: no atom
204 dirSet = 0; // build direction set based on atom symmetry
205 switch(symmetry[*p-'A']) {
206 case 'B': expo = 0; // bishop, slide
207 case 'F': // diagonal atom (degenerate 4-fold)
208 while(islower(*desc) && (i = dirType[*desc-'a']) != '0') {
209 int b = dirs1[*desc-'a']; // use wide version
210 if( islower(desc[1]) &&
211 ((i | dirType[desc[1]-'a']) & 3) == 3) { // combinable (perpendicular dim)
212 b = dirs1[*desc-'a'] & dirs1[desc[1]-'a']; // intersect wide & perp wide
217 dirSet &= 0x99; if(!dirSet) dirSet = 0x99;
219 case 'R': expo = 0; // rook, slide
220 case 'W': // orthogonal atom (non-deg 4-fold)
221 while(islower(*desc) && (dirType[*desc-'a'] & ~4) != '0') dirSet |= dirs2[*desc++-'a'];
222 dirSet &= 0x55; if(!dirSet) dirSet = 0x55;
224 case 'N': // oblique atom (degenerate 8-fold)
225 while(islower(*desc) && (i = dirType[*desc-'a']) != '0') {
226 int b = dirs2[*desc-'a']; // when alone, use narrow version
227 if(desc[1] == 'h') b = dirs1[*desc-'a'], desc += 2; // dirs1 is wide version
228 else if(islower(desc[1]) && i < '4'
229 && ((i | dirType[desc[1]-'a']) & 3) == 3) { // combinable (perpendicular dim)
230 b = dirs1[*desc-'a'] & dirs2[desc[1]-'a']; // intersect wide & perp narrow
235 if(!dirSet) dirSet = 0xFF;
237 case 'Q': expo = 0; // queen, slide
238 case 'K': // non-deg (pseudo) 8-fold
239 dirSet=0x55; // start with orthogonal moves
240 retry = 1; // and schedule the diagonal moves for later
241 break; // should not have direction indicators
242 default: return; // syntax error: invalid atom
244 if(mine == 2) dirSet = dirSet >> 4 | dirSet << 4 & 255; // invert black moves
245 mode = 0; // build mode mask
246 if(*desc == 'm') mode |= 4, desc++;
247 if(*desc == 'c') mode |= his, desc++;
248 if(*desc == 'd') mode |= mine, desc++;
249 if(*desc == 'e') mode |= 8, desc++;
250 if(!mode) mode = his + 4;// no mode spec, use default = mc
251 if(*desc == 'p') mode |= 32, desc++;
252 if(*desc == 'g') mode |= 64, desc++;
253 if(*desc == 'o') mode |= 128, desc++;
254 if(*desc == 'n') jump = 0, desc++;
255 while(*desc == 'j') jump++, desc++;
256 dx = xStep[*p-'A'] - '0'; // step vector of atom
257 dy = yStep[*p-'A'] - '0';
258 if(isdigit(*++p)) expo = atoi(p++); // read exponent
259 if(expo > 9) p++; // allow double-digit
260 desc = p; // this is start of next move
261 if(initial && (board[r][f] != initialPosition[r][f] ||
262 r == 0 && board[TOUCHED_W] & 1<<f ||
263 r == BOARD_HEIGHT-1 && board[TOUCHED_B] & 1<<f ) ) continue;
264 if(expo > 1 && dx == 0 && dy == 0) { // castling indicated by O + number
268 for(dir=0, bit=1; dir<8; dir++, bit += bit) { // loop over directions
269 int i = expo, hop = mode, vx, vy;
270 if(!(bit & dirSet)) continue; // does not move in this direction
271 vx = dx*rot[dir][0] + dy*rot[dir][1]; // rotate step vector
272 vy = dx*rot[dir][2] + dy*rot[dir][3];
273 x = f; y = r; // start square
275 x += vx; y += vy; // step to next square
276 if(y < 0 || y >= BOARD_HEIGHT) break; // vertically off-board: always done
277 if(x < BOARD_LEFT) { if(mode & 128) x += BOARD_RGHT - BOARD_LEFT; else break; }
278 if(x >= BOARD_RGHT) { if(mode & 128) x -= BOARD_RGHT - BOARD_LEFT; else break; }
279 if(!jump && board[y - vy + vy/2][x - vx + vx/2] != EmptySquare) break; // blocked
280 if(jump > 1 && board[y - vy + vy/2][x - vx + vx/2] == EmptySquare) break; // no hop
281 if(board[y][x] < BlackPawn) occup = 1; else
282 if(board[y][x] < EmptySquare) occup = 2; else
284 if(hop & 32+64) { if(occup != 4) { if(hop & 64 && i != 1) i = 2; hop &= 31; } continue; } // hopper
285 if(mode & 8 && y == board[EP_RANK] && occup == 4 && board[EP_FILE] == x) { // to e.p. square
286 cb(board, flags, mine == 1 ? WhiteCapturesEnPassant : BlackCapturesEnPassant, r, f, y, x, cl);
288 if(mode & 16) { // castling
289 i = 2; // kludge to elongate move indefinitely
290 if(occup == 4) continue; // skip empty squares
291 if(x == BOARD_LEFT && board[y][x] == initialPosition[y][x]) // reached initial corner piece
292 cb(board, flags, mine == 1 ? WhiteQueenSideCastle : BlackQueenSideCastle, r, f, y, f - expo, cl);
293 if(x == BOARD_RGHT-1 && board[y][x] == initialPosition[y][x])
294 cb(board, flags, mine == 1 ? WhiteKingSideCastle : BlackKingSideCastle, r, f, y, f + expo, cl);
297 if(occup & mode) cb(board, flags, NormalMove, r, f, y, x, cl); // allowed, generate
298 if(occup != 4) break; // not valid transit square
301 dx = dy = 1; dirSet = 0x99; // prepare for diagonal moves of K,Q
302 } while(retry--); // and start doing them
306 // [HGM] move generation now based on hierarchy of subroutines for rays and combinations of rays
309 SlideForward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
314 if (rt >= BOARD_HEIGHT) break;
315 if (SameColor(board[rf][ff], board[rt][ft])) break;
316 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
317 if (board[rt][ft] != EmptySquare) break;
322 SlideBackward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
328 if (SameColor(board[rf][ff], board[rt][ft])) break;
329 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
330 if (board[rt][ft] != EmptySquare) break;
335 SlideVertical (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
337 SlideForward(board, flags, rf, ff, callback, closure);
338 SlideBackward(board, flags, rf, ff, callback, closure);
342 SlideSideways (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
344 int i, s, rt = rf, ft;
345 for(s = -1; s <= 1; s+= 2) {
348 if (ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
349 if (SameColor(board[rf][ff], board[rt][ft])) break;
350 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
351 if (board[rt][ft] != EmptySquare) break;
357 SlideDiagForward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
360 for(s = -1; s <= 1; s+= 2) {
364 if (rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
365 if (SameColor(board[rf][ff], board[rt][ft])) break;
366 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
367 if (board[rt][ft] != EmptySquare) break;
373 SlideDiagBackward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
376 for(s = -1; s <= 1; s+= 2) {
380 if (rt < 0 || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
381 if (SameColor(board[rf][ff], board[rt][ft])) break;
382 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
383 if (board[rt][ft] != EmptySquare) break;
389 Rook (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
391 SlideVertical(board, flags, rf, ff, callback, closure);
392 SlideSideways(board, flags, rf, ff, callback, closure);
396 Bishop (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
398 SlideDiagForward(board, flags, rf, ff, callback, closure);
399 SlideDiagBackward(board, flags, rf, ff, callback, closure);
403 Sting (Board board, int flags, int rf, int ff, int dy, int dx, MoveCallback callback, VOIDSTAR closure)
404 { // Lion-like move of Horned Falcon and Souring Eagle
405 int ft = ff + dx, rt = rf + dy;
406 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) return;
407 if (!SameColor(board[rf][ff], board[rt][ft]))
408 callback(board, flags, board[rt][ft] != EmptySquare ? FirstLeg : NormalMove, rf, ff, rt, ft, closure);
410 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) return;
411 if (!SameColor(board[rf][ff], board[rt][ft]))
412 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
416 StepForward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
418 int ft = ff, rt = rf + 1;
419 if (rt >= BOARD_HEIGHT) return;
420 if (SameColor(board[rf][ff], board[rt][ft])) return;
421 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
425 StepBackward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
427 int ft = ff, rt = rf - 1;
429 if (SameColor(board[rf][ff], board[rt][ft])) return;
430 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
434 StepSideways (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
438 if (!(rt >= BOARD_HEIGHT || ft >= BOARD_RGHT) && !SameColor(board[rf][ff], board[rt][ft]))
439 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
441 if (!(rt >= BOARD_HEIGHT || ft < BOARD_LEFT) && !SameColor(board[rf][ff], board[rt][ft]))
442 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
446 StepDiagForward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
449 if (rt >= BOARD_HEIGHT) return;
451 if (!(rt >= BOARD_HEIGHT || ft >= BOARD_RGHT) && !SameColor(board[rf][ff], board[rt][ft]))
452 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
454 if (!(rt >= BOARD_HEIGHT || ft < BOARD_LEFT) && !SameColor(board[rf][ff], board[rt][ft]))
455 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
459 StepDiagBackward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
464 if (!(rt < 0 || ft >= BOARD_RGHT) && !SameColor(board[rf][ff], board[rt][ft]))
465 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
467 if (!(rt < 0 || ft < BOARD_LEFT) && !SameColor(board[rf][ff], board[rt][ft]))
468 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
472 StepVertical (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
474 StepForward(board, flags, rf, ff, callback, closure);
475 StepBackward(board, flags, rf, ff, callback, closure);
479 Ferz (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
481 StepDiagForward(board, flags, rf, ff, callback, closure);
482 StepDiagBackward(board, flags, rf, ff, callback, closure);
486 Wazir (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
488 StepVertical(board, flags, rf, ff, callback, closure);
489 StepSideways(board, flags, rf, ff, callback, closure);
493 Knight (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
496 for (i = -1; i <= 1; i += 2)
497 for (j = -1; j <= 1; j += 2)
498 for (s = 1; s <= 2; s++) {
501 if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
502 && ( gameInfo.variant != VariantXiangqi || board[rf+i*(s-1)][ff+j*(2-s)] == EmptySquare)
503 && !SameColor(board[rf][ff], board[rt][ft]))
504 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
508 /* Call callback once for each pseudo-legal move in the given
509 position, except castling moves. A move is pseudo-legal if it is
510 legal, or if it would be legal except that it leaves the king in
511 check. In the arguments, epfile is EP_NONE if the previous move
512 was not a double pawn push, or the file 0..7 if it was, or
513 EP_UNKNOWN if we don't know and want to allow all e.p. captures.
514 Promotion moves generated are to Queen only.
517 GenPseudoLegal (Board board, int flags, MoveCallback callback, VOIDSTAR closure, ChessSquare filter)
518 // speed: only do moves with this piece type
521 int i, j, d, s, fs, rs, rt, ft, m;
522 int epfile = (signed char)board[EP_STATUS]; // [HGM] gamestate: extract ep status from board
523 int promoRank = gameInfo.variant == VariantMakruk || gameInfo.variant == VariantGrand || gameInfo.variant == VariantChuChess ? 3 : 1;
525 for (rf = 0; rf < BOARD_HEIGHT; rf++)
526 for (ff = BOARD_LEFT; ff < BOARD_RGHT; ff++) {
529 if(board[rf][ff] == EmptySquare) continue;
530 if ((flags & F_WHITE_ON_MOVE) != (board[rf][ff] < BlackPawn)) continue; // [HGM] speed: wrong color
531 m = 0; piece = board[rf][ff];
532 if(PieceToChar(piece) == '~')
533 piece = (ChessSquare) ( DEMOTED piece );
534 if(filter != EmptySquare && piece != filter) continue;
535 if(pieceDesc[piece]) { MovesFromString(board, flags, ff, rf, pieceDesc[piece], callback, closure); continue; } // [HGM] gen
536 if(IS_SHOGI(gameInfo.variant))
537 piece = (ChessSquare) ( SHOGI piece );
539 switch ((int)piece) {
540 /* case EmptySquare: [HGM] this is nonsense, and conflicts with Shogi cases */
542 /* can't happen ([HGM] except for faries...) */
546 if(gameInfo.variant == VariantXiangqi) {
547 /* [HGM] capture and move straight ahead in Xiangqi */
548 if (rf < BOARD_HEIGHT-1 &&
549 !SameColor(board[rf][ff], board[rf + 1][ff]) ) {
550 callback(board, flags, NormalMove,
551 rf, ff, rf + 1, ff, closure);
553 /* and move sideways when across the river */
554 for (s = -1; s <= 1; s += 2) {
555 if (rf >= BOARD_HEIGHT>>1 &&
556 ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
557 !WhitePiece(board[rf][ff+s]) ) {
558 callback(board, flags, NormalMove,
559 rf, ff, rf, ff+s, closure);
564 if (rf < BOARD_HEIGHT-1 && board[rf + 1][ff] == EmptySquare) {
565 callback(board, flags,
566 rf >= BOARD_HEIGHT-1-promoRank ? WhitePromotion : NormalMove,
567 rf, ff, rf + 1, ff, closure);
569 if (rf <= (BOARD_HEIGHT>>1)-3 && board[rf+1][ff] == EmptySquare && // [HGM] grand: also on 3rd rank on 10-board
570 gameInfo.variant != VariantShatranj && /* [HGM] */
571 gameInfo.variant != VariantCourier && /* [HGM] */
572 board[rf+2][ff] == EmptySquare ) {
573 callback(board, flags, NormalMove,
574 rf, ff, rf+2, ff, closure);
576 for (s = -1; s <= 1; s += 2) {
577 if (rf < BOARD_HEIGHT-1 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
578 ((flags & F_KRIEGSPIEL_CAPTURE) ||
579 BlackPiece(board[rf + 1][ff + s]))) {
580 callback(board, flags,
581 rf >= BOARD_HEIGHT-1-promoRank ? WhitePromotion : NormalMove,
582 rf, ff, rf + 1, ff + s, closure);
584 if (rf >= BOARD_HEIGHT+1>>1) {// [HGM] grand: 4th & 5th rank on 10-board
585 if (ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
586 (epfile == ff + s || epfile == EP_UNKNOWN) && rf < BOARD_HEIGHT-3 &&
587 board[rf][ff + s] == BlackPawn &&
588 board[rf+1][ff + s] == EmptySquare) {
589 callback(board, flags, WhiteCapturesEnPassant,
590 rf, ff, rf+1, ff + s, closure);
597 if(gameInfo.variant == VariantXiangqi) {
598 /* [HGM] capture straight ahead in Xiangqi */
599 if (rf > 0 && !SameColor(board[rf][ff], board[rf - 1][ff]) ) {
600 callback(board, flags, NormalMove,
601 rf, ff, rf - 1, ff, closure);
603 /* and move sideways when across the river */
604 for (s = -1; s <= 1; s += 2) {
605 if (rf < BOARD_HEIGHT>>1 &&
606 ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
607 !BlackPiece(board[rf][ff+s]) ) {
608 callback(board, flags, NormalMove,
609 rf, ff, rf, ff+s, closure);
614 if (rf > 0 && board[rf - 1][ff] == EmptySquare) {
615 callback(board, flags,
616 rf <= promoRank ? BlackPromotion : NormalMove,
617 rf, ff, rf - 1, ff, closure);
619 if (rf >= (BOARD_HEIGHT+1>>1)+2 && board[rf-1][ff] == EmptySquare && // [HGM] grand
620 gameInfo.variant != VariantShatranj && /* [HGM] */
621 gameInfo.variant != VariantCourier && /* [HGM] */
622 board[rf-2][ff] == EmptySquare) {
623 callback(board, flags, NormalMove,
624 rf, ff, rf-2, ff, closure);
626 for (s = -1; s <= 1; s += 2) {
627 if (rf > 0 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
628 ((flags & F_KRIEGSPIEL_CAPTURE) ||
629 WhitePiece(board[rf - 1][ff + s]))) {
630 callback(board, flags,
631 rf <= promoRank ? BlackPromotion : NormalMove,
632 rf, ff, rf - 1, ff + s, closure);
634 if (rf < BOARD_HEIGHT>>1) {
635 if (ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
636 (epfile == ff + s || epfile == EP_UNKNOWN) && rf > 2 &&
637 board[rf][ff + s] == WhitePawn &&
638 board[rf-1][ff + s] == EmptySquare) {
639 callback(board, flags, BlackCapturesEnPassant,
640 rf, ff, rf-1, ff + s, closure);
650 for (i = -1; i <= 1; i += 2)
651 for (j = -1; j <= 1; j += 2)
652 for (s = 1; s <= 2; s++) {
655 if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
656 && ( gameInfo.variant != VariantXiangqi || board[rf+i*(s-1)][ff+j*(2-s)] == EmptySquare)
657 && !SameColor(board[rf][ff], board[rt][ft]))
658 callback(board, flags, NormalMove,
659 rf, ff, rt, ft, closure);
663 case SHOGI WhiteKnight:
664 for (s = -1; s <= 1; s += 2) {
665 if (rf < BOARD_HEIGHT-2 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
666 !SameColor(board[rf][ff], board[rf + 2][ff + s])) {
667 callback(board, flags, NormalMove,
668 rf, ff, rf + 2, ff + s, closure);
673 case SHOGI BlackKnight:
674 for (s = -1; s <= 1; s += 2) {
675 if (rf > 1 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
676 !SameColor(board[rf][ff], board[rf - 2][ff + s])) {
677 callback(board, flags, NormalMove,
678 rf, ff, rf - 2, ff + s, closure);
685 for (d = 0; d <= 1; d++)
686 for (s = -1; s <= 1; s += 2) {
689 rt = rf + (i * s) * d;
690 ft = ff + (i * s) * (1 - d);
691 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
692 if (m == 0 && board[rt][ft] == EmptySquare)
693 callback(board, flags, NormalMove,
694 rf, ff, rt, ft, closure);
695 if (m == 1 && board[rt][ft] != EmptySquare &&
696 !SameColor(board[rf][ff], board[rt][ft]) )
697 callback(board, flags, NormalMove,
698 rf, ff, rt, ft, closure);
699 if (board[rt][ft] != EmptySquare && m++) break;
704 /* Gold General (and all its promoted versions) . First do the */
705 /* diagonal forward steps, then proceed as normal Wazir */
706 case SHOGI (PROMOTED WhitePawn):
707 if(gameInfo.variant == VariantShogi) goto WhiteGold;
708 case SHOGI (PROMOTED BlackPawn):
709 if(gameInfo.variant == VariantShogi) goto BlackGold;
710 SlideVertical(board, flags, rf, ff, callback, closure);
713 case SHOGI (PROMOTED WhiteKnight):
714 if(gameInfo.variant == VariantShogi) goto WhiteGold;
715 case SHOGI BlackDrunk:
716 case SHOGI BlackAlfil:
717 Ferz(board, flags, rf, ff, callback, closure);
718 StepSideways(board, flags, rf, ff, callback, closure);
719 StepBackward(board, flags, rf, ff, callback, closure);
722 case SHOGI (PROMOTED BlackKnight):
723 if(gameInfo.variant == VariantShogi) goto BlackGold;
724 case SHOGI WhiteDrunk:
725 case SHOGI WhiteAlfil:
726 Ferz(board, flags, rf, ff, callback, closure);
727 StepSideways(board, flags, rf, ff, callback, closure);
728 StepForward(board, flags, rf, ff, callback, closure);
732 case SHOGI WhiteStag:
733 case SHOGI BlackStag:
734 if(gameInfo.variant == VariantShogi) goto BlackGold;
735 SlideVertical(board, flags, rf, ff, callback, closure);
736 Ferz(board, flags, rf, ff, callback, closure);
737 StepSideways(board, flags, rf, ff, callback, closure);
740 case SHOGI (PROMOTED WhiteQueen):
741 case SHOGI WhiteTokin:
742 case SHOGI WhiteWazir:
744 StepDiagForward(board, flags, rf, ff, callback, closure);
745 Wazir(board, flags, rf, ff, callback, closure);
748 case SHOGI (PROMOTED BlackQueen):
749 case SHOGI BlackTokin:
750 case SHOGI BlackWazir:
752 StepDiagBackward(board, flags, rf, ff, callback, closure);
753 Wazir(board, flags, rf, ff, callback, closure);
758 Wazir(board, flags, rf, ff, callback, closure);
761 case SHOGI WhiteMarshall:
762 case SHOGI BlackMarshall:
763 Ferz(board, flags, rf, ff, callback, closure);
764 for (d = 0; d <= 1; d++)
765 for (s = -2; s <= 2; s += 4) {
767 ft = ff + s * (1 - d);
768 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) continue;
769 if (!SameColor(board[rf][ff], board[rt][ft]) )
770 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
774 case SHOGI WhiteAngel:
775 case SHOGI BlackAngel:
776 Wazir(board, flags, rf, ff, callback, closure);
780 /* [HGM] support Shatranj pieces */
781 for (rs = -1; rs <= 1; rs += 2)
782 for (fs = -1; fs <= 1; fs += 2) {
785 if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
786 && ( gameInfo.variant != VariantXiangqi ||
787 board[rf+rs][ff+fs] == EmptySquare && (2*rf < BOARD_HEIGHT) == (2*rt < BOARD_HEIGHT) )
789 && !SameColor(board[rf][ff], board[rt][ft]))
790 callback(board, flags, NormalMove,
791 rf, ff, rt, ft, closure);
792 if(gameInfo.variant == VariantShatranj || gameInfo.variant == VariantCourier ||
793 gameInfo.variant == VariantChu || gameInfo.variant == VariantXiangqi) continue; // classical Alfil
794 rt = rf + rs; // in unknown variant we assume Modern Elephant, which can also do one step
796 if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
797 && !SameColor(board[rf][ff], board[rt][ft]))
798 callback(board, flags, NormalMove,
799 rf, ff, rt, ft, closure);
801 if(gameInfo.variant == VariantSpartan)
802 for(fs = -1; fs <= 1; fs += 2) {
804 if (!(ft < BOARD_LEFT || ft >= BOARD_RGHT) && board[rf][ft] == EmptySquare)
805 callback(board, flags, NormalMove, rf, ff, rf, ft, closure);
809 /* Make Dragon-Horse also do Dababba moves outside Shogi, for better disambiguation in variant Fairy */
812 if(gameInfo.variant == VariantChuChess) goto DragonHorse;
813 for (d = 0; d <= 1; d++) // Dababba moves that Rook cannot do
814 for (s = -2; s <= 2; s += 4) {
816 ft = ff + s * (1 - d);
817 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) continue;
818 if (SameColor(board[rf][ff], board[rt][ft])) continue;
819 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
822 /* Shogi Dragon Horse has to continue with Wazir after Bishop */
823 case SHOGI WhiteCardinal:
824 case SHOGI BlackCardinal:
825 case SHOGI WhitePCardinal:
826 case SHOGI BlackPCardinal:
828 Bishop(board, flags, rf, ff, callback, closure);
829 Wazir(board, flags, rf, ff, callback, closure);
832 /* Capablanca Archbishop continues as Knight */
835 Knight(board, flags, rf, ff, callback, closure);
837 /* Shogi Bishops are ordinary Bishops */
838 case SHOGI WhiteBishop:
839 case SHOGI BlackBishop:
840 case SHOGI WhitePBishop:
841 case SHOGI BlackPBishop:
844 Bishop(board, flags, rf, ff, callback, closure);
847 /* Shogi Lance is unlike anything, and asymmetric at that */
848 case SHOGI WhiteQueen:
849 if(gameInfo.variant == VariantChu) goto doQueen;
853 if (rt >= BOARD_HEIGHT) break;
854 if (SameColor(board[rf][ff], board[rt][ft])) break;
855 callback(board, flags, NormalMove,
856 rf, ff, rt, ft, closure);
857 if (board[rt][ft] != EmptySquare) break;
861 case SHOGI BlackQueen:
862 if(gameInfo.variant == VariantChu) goto doQueen;
867 if (SameColor(board[rf][ff], board[rt][ft])) break;
868 callback(board, flags, NormalMove,
869 rf, ff, rt, ft, closure);
870 if (board[rt][ft] != EmptySquare) break;
874 /* Make Dragon-King Dababba & Rook-like outside Shogi, for better disambiguation in variant Fairy */
877 if(gameInfo.variant == VariantChuChess) goto DragonKing;
878 for (d = 0; d <= 1; d++) // Dababba moves that Rook cannot do
879 for (s = -2; s <= 2; s += 4) {
881 ft = ff + s * (1 - d);
882 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) continue;
883 if (board[rf+rt>>1][ff+ft>>1] == EmptySquare && gameInfo.variant != VariantSpartan) continue;
884 if (SameColor(board[rf][ff], board[rt][ft])) continue;
885 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
887 if(gameInfo.variant == VariantSpartan) // in Spartan Chess restrict range to modern Dababba
888 Wazir(board, flags, rf, ff, callback, closure);
890 Rook(board, flags, rf, ff, callback, closure);
893 /* Shogi Dragon King has to continue as Ferz after Rook moves */
894 case SHOGI WhiteDragon:
895 case SHOGI BlackDragon:
896 case SHOGI WhitePDragon:
897 case SHOGI BlackPDragon:
899 Rook(board, flags, rf, ff, callback, closure);
900 Ferz(board, flags, rf, ff, callback, closure);
904 /* Capablanca Chancellor sets flag to continue as Knight */
907 Rook(board, flags, rf, ff, callback, closure);
908 if(gameInfo.variant == VariantSpartan) // in Spartan Chess Chancellor is used for Dragon King.
909 Ferz(board, flags, rf, ff, callback, closure);
911 Knight(board, flags, rf, ff, callback, closure);
914 /* Shogi Rooks are ordinary Rooks */
915 case SHOGI WhiteRook:
916 case SHOGI BlackRook:
917 case SHOGI WhitePRook:
918 case SHOGI BlackPRook:
921 Rook(board, flags, rf, ff, callback, closure);
926 case SHOGI WhiteMother:
927 case SHOGI BlackMother:
929 Rook(board, flags, rf, ff, callback, closure);
930 Bishop(board, flags, rf, ff, callback, closure);
933 case SHOGI WhitePawn:
934 StepForward(board, flags, rf, ff, callback, closure);
937 case SHOGI BlackPawn:
938 StepBackward(board, flags, rf, ff, callback, closure);
942 if(gameInfo.variant != VariantMakruk && gameInfo.variant != VariantASEAN) goto commoner;
943 case SHOGI WhiteFerz:
944 Ferz(board, flags, rf, ff, callback, closure);
945 StepForward(board, flags, rf, ff, callback, closure);
949 if(gameInfo.variant != VariantMakruk && gameInfo.variant != VariantASEAN) goto commoner;
950 case SHOGI BlackFerz:
951 StepBackward(board, flags, rf, ff, callback, closure);
955 /* [HGM] support Shatranj pieces */
956 Ferz(board, flags, rf, ff, callback, closure);
961 Knight(board, flags, rf, ff, callback, closure); // [HGM] superchess: use for Centaur
964 case SHOGI WhiteMonarch:
965 case SHOGI BlackMonarch:
966 case SHOGI WhiteKing:
967 case SHOGI BlackKing:
970 Ferz(board, flags, rf, ff, callback, closure);
971 Wazir(board, flags, rf, ff, callback, closure);
974 case WhiteNightrider:
975 case BlackNightrider:
976 for (i = -1; i <= 1; i += 2)
977 for (j = -1; j <= 1; j += 2)
978 for (s = 1; s <= 2; s++) { int k;
982 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
983 if (SameColor(board[rf][ff], board[rt][ft])) break;
984 callback(board, flags, NormalMove,
985 rf, ff, rt, ft, closure);
986 if (board[rt][ft] != EmptySquare) break;
992 Bishop(board, flags, rf, ff, callback, closure);
993 Rook(board, flags, rf, ff, callback, closure);
994 Knight(board, flags, rf, ff, callback, closure);
997 // Use Lance as Berolina / Spartan Pawn.
999 if(gameInfo.variant == VariantSuper) goto Amazon;
1000 if (rf < BOARD_HEIGHT-1 && BlackPiece(board[rf + 1][ff]))
1001 callback(board, flags,
1002 rf >= BOARD_HEIGHT-1-promoRank ? WhitePromotion : NormalMove,
1003 rf, ff, rf + 1, ff, closure);
1004 for (s = -1; s <= 1; s += 2) {
1005 if (rf < BOARD_HEIGHT-1 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT && board[rf + 1][ff + s] == EmptySquare)
1006 callback(board, flags,
1007 rf >= BOARD_HEIGHT-1-promoRank ? WhitePromotion : NormalMove,
1008 rf, ff, rf + 1, ff + s, closure);
1009 if (rf == 1 && ff + 2*s >= BOARD_LEFT && ff + 2*s < BOARD_RGHT && board[3][ff + 2*s] == EmptySquare )
1010 callback(board, flags, NormalMove, rf, ff, 3, ff + 2*s, closure);
1015 if(gameInfo.variant == VariantSuper) goto Amazon;
1016 if (rf > 0 && WhitePiece(board[rf - 1][ff]))
1017 callback(board, flags,
1018 rf <= promoRank ? BlackPromotion : NormalMove,
1019 rf, ff, rf - 1, ff, closure);
1020 for (s = -1; s <= 1; s += 2) {
1021 if (rf > 0 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT && board[rf - 1][ff + s] == EmptySquare)
1022 callback(board, flags,
1023 rf <= promoRank ? BlackPromotion : NormalMove,
1024 rf, ff, rf - 1, ff + s, closure);
1025 if (rf == BOARD_HEIGHT-2 && ff + 2*s >= BOARD_LEFT && ff + 2*s < BOARD_RGHT && board[rf-2][ff + 2*s] == EmptySquare )
1026 callback(board, flags, NormalMove, rf, ff, rf-2, ff + 2*s, closure);
1030 case SHOGI WhiteNothing:
1031 case SHOGI BlackNothing:
1032 case SHOGI WhiteLion:
1033 case SHOGI BlackLion:
1036 for(rt = rf - 2; rt <= rf + 2; rt++) for(ft = ff - 2; ft <= ff + 2; ft++) {
1037 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) continue;
1038 if (!(ff == ft && rf == rt) && SameColor(board[rf][ff], board[rt][ft])) continue;
1039 callback(board, flags, (rt-rf)*(rt-rf) + (ff-ft)*(ff-ft) < 3 && board[rt][ft] != EmptySquare ? FirstLeg : NormalMove,
1040 rf, ff, rt, ft, closure);
1044 case SHOGI WhiteFalcon:
1045 case SHOGI BlackFalcon:
1046 case SHOGI WhitePDagger:
1047 case SHOGI BlackPDagger:
1048 SlideSideways(board, flags, rf, ff, callback, closure);
1049 StepVertical(board, flags, rf, ff, callback, closure);
1052 case SHOGI WhiteCobra:
1053 case SHOGI BlackCobra:
1054 StepVertical(board, flags, rf, ff, callback, closure);
1057 case SHOGI (PROMOTED WhiteFerz):
1058 if(gameInfo.variant == VariantShogi) goto WhiteGold;
1059 case SHOGI (PROMOTED BlackFerz):
1060 if(gameInfo.variant == VariantShogi) goto BlackGold;
1061 case SHOGI WhitePSword:
1062 case SHOGI BlackPSword:
1063 SlideVertical(board, flags, rf, ff, callback, closure);
1064 StepSideways(board, flags, rf, ff, callback, closure);
1067 case SHOGI WhiteUnicorn:
1068 case SHOGI BlackUnicorn:
1069 Ferz(board, flags, rf, ff, callback, closure);
1070 StepVertical(board, flags, rf, ff, callback, closure);
1073 case SHOGI WhiteMan:
1074 StepDiagForward(board, flags, rf, ff, callback, closure);
1075 StepVertical(board, flags, rf, ff, callback, closure);
1078 case SHOGI BlackMan:
1079 StepDiagBackward(board, flags, rf, ff, callback, closure);
1080 StepVertical(board, flags, rf, ff, callback, closure);
1083 case SHOGI WhiteHCrown:
1084 case SHOGI BlackHCrown:
1085 Bishop(board, flags, rf, ff, callback, closure);
1086 SlideSideways(board, flags, rf, ff, callback, closure);
1089 case SHOGI WhiteCrown:
1090 case SHOGI BlackCrown:
1091 Bishop(board, flags, rf, ff, callback, closure);
1092 SlideVertical(board, flags, rf, ff, callback, closure);
1095 case SHOGI WhiteHorned:
1096 Sting(board, flags, rf, ff, 1, 0, callback, closure);
1097 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1098 if(killX >= 0) break;
1099 Bishop(board, flags, rf, ff, callback, closure);
1100 SlideSideways(board, flags, rf, ff, callback, closure);
1101 SlideBackward(board, flags, rf, ff, callback, closure);
1104 case SHOGI BlackHorned:
1105 Sting(board, flags, rf, ff, -1, 0, callback, closure);
1106 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1107 if(killX >= 0) break;
1108 Bishop(board, flags, rf, ff, callback, closure);
1109 SlideSideways(board, flags, rf, ff, callback, closure);
1110 SlideForward(board, flags, rf, ff, callback, closure);
1113 case SHOGI WhiteEagle:
1114 Sting(board, flags, rf, ff, 1, 1, callback, closure);
1115 Sting(board, flags, rf, ff, 1, -1, callback, closure);
1116 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1117 if(killX >= 0) break;
1118 Rook(board, flags, rf, ff, callback, closure);
1119 SlideDiagBackward(board, flags, rf, ff, callback, closure);
1122 case SHOGI BlackEagle:
1123 Sting(board, flags, rf, ff, -1, 1, callback, closure);
1124 Sting(board, flags, rf, ff, -1, -1, callback, closure);
1125 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1126 if(killX >= 0) break;
1127 Rook(board, flags, rf, ff, callback, closure);
1128 SlideDiagForward(board, flags, rf, ff, callback, closure);
1131 case SHOGI WhiteDolphin:
1132 case SHOGI BlackHorse:
1133 SlideDiagBackward(board, flags, rf, ff, callback, closure);
1134 SlideVertical(board, flags, rf, ff, callback, closure);
1137 case SHOGI BlackDolphin:
1138 case SHOGI WhiteHorse:
1139 SlideDiagForward(board, flags, rf, ff, callback, closure);
1140 SlideVertical(board, flags, rf, ff, callback, closure);
1143 case SHOGI WhiteLance:
1144 SlideForward(board, flags, rf, ff, callback, closure);
1147 case SHOGI BlackLance:
1148 SlideBackward(board, flags, rf, ff, callback, closure);
1151 case WhiteFalcon: // [HGM] wild: for wildcards, self-capture symbolizes move to anywhere
1155 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1168 int rFilter, fFilter; // [HGM] speed: sorry, but I get a bit tired of this closure madness
1169 Board xqCheckers, nullBoard;
1171 extern void GenLegalCallback P((Board board, int flags, ChessMove kind,
1172 int rf, int ff, int rt, int ft,
1176 GenLegalCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1178 register GenLegalClosure *cl = (GenLegalClosure *) closure;
1180 if(rFilter >= 0 && rFilter != rt || fFilter >= 0 && fFilter != ft) return; // [HGM] speed: ignore moves with wrong to-square
1182 if (board[EP_STATUS] == EP_IRON_LION && (board[rt][ft] == WhiteLion || board[rt][ft] == BlackLion)) return; //[HGM] lion
1184 if (!(flags & F_IGNORE_CHECK) ) {
1185 int check, promo = (gameInfo.variant == VariantSpartan && kind == BlackPromotion);
1188 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++)
1189 kings += (board[r][f] == BlackKing);
1193 board[rf][ff] = BlackKing; // [HGM] spartan: promote to King before check-test
1195 check = CheckTest(board, flags, rf, ff, rt, ft,
1196 kind == WhiteCapturesEnPassant ||
1197 kind == BlackCapturesEnPassant);
1198 if(promo) board[rf][ff] = BlackLance;
1201 if (flags & F_ATOMIC_CAPTURE) {
1202 if (board[rt][ft] != EmptySquare ||
1203 kind == WhiteCapturesEnPassant || kind == BlackCapturesEnPassant) {
1205 ChessSquare king = (flags & F_WHITE_ON_MOVE) ? WhiteKing : BlackKing;
1206 if (board[rf][ff] == king) return;
1207 for (r = rt-1; r <= rt+1; r++) {
1208 for (f = ft-1; f <= ft+1; f++) {
1209 if (r >= 0 && r < BOARD_HEIGHT && f >= BOARD_LEFT && f < BOARD_RGHT &&
1210 board[r][f] == king) return;
1215 cl->cb(board, flags, kind, rf, ff, rt, ft, cl->cl);
1222 int captures; // [HGM] losers
1223 } LegalityTestClosure;
1226 /* Like GenPseudoLegal, but (1) include castling moves, (2) unless
1227 F_IGNORE_CHECK is set in the flags, omit moves that would leave the
1228 king in check, and (3) if F_ATOMIC_CAPTURE is set in the flags, omit
1229 moves that would destroy your own king. The CASTLE_OK flags are
1230 true if castling is not yet ruled out by a move of the king or
1231 rook. Return TRUE if the player on move is currently in check and
1232 F_IGNORE_CHECK is not set. [HGM] add castlingRights parameter */
1234 GenLegal (Board board, int flags, MoveCallback callback, VOIDSTAR closure, ChessSquare filter)
1237 int ff, ft, k, left, right, swap;
1238 int ignoreCheck = (flags & F_IGNORE_CHECK) != 0;
1239 ChessSquare wKing = WhiteKing, bKing = BlackKing, *castlingRights = board[CASTLING];
1240 int inCheck = !ignoreCheck && CheckTest(board, flags, -1, -1, -1, -1, FALSE); // kludge alert: this would mark pre-existing checkers if status==1
1245 xqCheckers[EP_STATUS] *= 2; // quasi: if previous CheckTest has been marking, we now set flag for suspending same checkers
1246 if(filter == EmptySquare) rFilter = fFilter = -1; // [HGM] speed: do not filter on square if we do not filter on piece
1247 GenPseudoLegal(board, flags, GenLegalCallback, (VOIDSTAR) &cl, filter);
1249 if (inCheck) return TRUE;
1251 /* Generate castling moves */
1252 if(gameInfo.variant == VariantKnightmate) { /* [HGM] Knightmate */
1253 wKing = WhiteUnicorn; bKing = BlackUnicorn;
1256 p = (flags & F_WHITE_ON_MOVE ? pieceDesc[wKing] : pieceDesc[bKing]);
1257 if(p && strchr(p, 'O')) return FALSE; // [HGM] gen: castlings were already generated from string
1259 for (ff = BOARD_WIDTH>>1; ff >= (BOARD_WIDTH-1)>>1; ff-- /*ics wild 1*/) {
1260 if ((flags & F_WHITE_ON_MOVE) &&
1261 (flags & F_WHITE_KCASTLE_OK) &&
1262 board[0][ff] == wKing &&
1263 board[0][ff + 1] == EmptySquare &&
1264 board[0][ff + 2] == EmptySquare &&
1265 board[0][BOARD_RGHT-3] == EmptySquare &&
1266 board[0][BOARD_RGHT-2] == EmptySquare &&
1267 board[0][BOARD_RGHT-1] == WhiteRook &&
1268 castlingRights[0] != NoRights && /* [HGM] check rights */
1269 ( castlingRights[2] == ff || castlingRights[6] == ff ) &&
1271 (!CheckTest(board, flags, 0, ff, 0, ff + 1, FALSE) &&
1272 !CheckTest(board, flags, 0, ff, 0, BOARD_RGHT-3, FALSE) &&
1273 (gameInfo.variant != VariantJanus || !CheckTest(board, flags, 0, ff, 0, BOARD_RGHT-2, FALSE)) &&
1274 !CheckTest(board, flags, 0, ff, 0, ff + 2, FALSE)))) {
1276 callback(board, flags,
1277 ff==BOARD_WIDTH>>1 ? WhiteKingSideCastle : WhiteKingSideCastleWild,
1278 0, ff, 0, ff + ((gameInfo.boardWidth+2)>>2) + (gameInfo.variant == VariantJanus), closure);
1280 if ((flags & F_WHITE_ON_MOVE) &&
1281 (flags & F_WHITE_QCASTLE_OK) &&
1282 board[0][ff] == wKing &&
1283 board[0][ff - 1] == EmptySquare &&
1284 board[0][ff - 2] == EmptySquare &&
1285 board[0][BOARD_LEFT+2] == EmptySquare &&
1286 board[0][BOARD_LEFT+1] == EmptySquare &&
1287 board[0][BOARD_LEFT+0] == WhiteRook &&
1288 castlingRights[1] != NoRights && /* [HGM] check rights */
1289 ( castlingRights[2] == ff || castlingRights[6] == ff ) &&
1291 (!CheckTest(board, flags, 0, ff, 0, ff - 1, FALSE) &&
1292 !CheckTest(board, flags, 0, ff, 0, BOARD_LEFT+3, FALSE) &&
1293 !CheckTest(board, flags, 0, ff, 0, ff - 2, FALSE)))) {
1295 callback(board, flags,
1296 ff==BOARD_WIDTH>>1 ? WhiteQueenSideCastle : WhiteQueenSideCastleWild,
1297 0, ff, 0, ff - ((gameInfo.boardWidth+2)>>2), closure);
1299 if (!(flags & F_WHITE_ON_MOVE) &&
1300 (flags & F_BLACK_KCASTLE_OK) &&
1301 board[BOARD_HEIGHT-1][ff] == bKing &&
1302 board[BOARD_HEIGHT-1][ff + 1] == EmptySquare &&
1303 board[BOARD_HEIGHT-1][ff + 2] == EmptySquare &&
1304 board[BOARD_HEIGHT-1][BOARD_RGHT-3] == EmptySquare &&
1305 board[BOARD_HEIGHT-1][BOARD_RGHT-2] == EmptySquare &&
1306 board[BOARD_HEIGHT-1][BOARD_RGHT-1] == BlackRook &&
1307 castlingRights[3] != NoRights && /* [HGM] check rights */
1308 ( castlingRights[5] == ff || castlingRights[7] == ff ) &&
1310 (!CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff + 1, FALSE) &&
1311 !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, BOARD_RGHT-3, FALSE) &&
1312 (gameInfo.variant != VariantJanus || !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, BOARD_RGHT-2, FALSE)) &&
1313 !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff + 2, FALSE)))) {
1315 callback(board, flags,
1316 ff==BOARD_WIDTH>>1 ? BlackKingSideCastle : BlackKingSideCastleWild,
1317 BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff + ((gameInfo.boardWidth+2)>>2) + (gameInfo.variant == VariantJanus), closure);
1319 if (!(flags & F_WHITE_ON_MOVE) &&
1320 (flags & F_BLACK_QCASTLE_OK) &&
1321 board[BOARD_HEIGHT-1][ff] == bKing &&
1322 board[BOARD_HEIGHT-1][ff - 1] == EmptySquare &&
1323 board[BOARD_HEIGHT-1][ff - 2] == EmptySquare &&
1324 board[BOARD_HEIGHT-1][BOARD_LEFT+2] == EmptySquare &&
1325 board[BOARD_HEIGHT-1][BOARD_LEFT+1] == EmptySquare &&
1326 board[BOARD_HEIGHT-1][BOARD_LEFT+0] == BlackRook &&
1327 castlingRights[4] != NoRights && /* [HGM] check rights */
1328 ( castlingRights[5] == ff || castlingRights[7] == ff ) &&
1330 (!CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff - 1, FALSE) &&
1331 !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, BOARD_LEFT+3, FALSE) &&
1332 !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff - 2, FALSE)))) {
1334 callback(board, flags,
1335 ff==BOARD_WIDTH>>1 ? BlackQueenSideCastle : BlackQueenSideCastleWild,
1336 BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff - ((gameInfo.boardWidth+2)>>2), closure);
1340 if((swap = gameInfo.variant == VariantSChess) || flags & F_FRC_TYPE_CASTLING) {
1342 /* generate all potential FRC castling moves (KxR), ignoring flags */
1343 /* [HGM] test if the Rooks we find have castling rights */
1344 /* In S-Chess we generate RxK for allowed castlings, for gating at Rook square */
1347 if ((flags & F_WHITE_ON_MOVE) != 0) {
1348 ff = castlingRights[2]; /* King file if we have any rights */
1349 if(ff != NoRights && board[0][ff] == WhiteKing) {
1350 if (appData.debugMode) {
1351 fprintf(debugFP, "FRC castling, %d %d %d %d %d %d\n",
1352 castlingRights[0],castlingRights[1],ff,castlingRights[3],castlingRights[4],castlingRights[5]);
1354 ft = castlingRights[0]; /* Rook file if we have H-side rights */
1356 right = BOARD_RGHT-2;
1357 if(ff == BOARD_RGHT-2) left = right = ff-1; /* special case */
1358 for(k=left; k<=right && ft != NoRights; k++) /* first test if blocked */
1359 if(k != ft && board[0][k] != EmptySquare) ft = NoRights;
1360 for(k=left; k<right && ft != NoRights; k++) /* then if not checked */
1361 if(!ignoreCheck && CheckTest(board, flags, 0, ff, 0, k, FALSE)) ft = NoRights;
1362 if(ft != NoRights && board[0][ft] == WhiteRook) {
1363 if(flags & F_FRC_TYPE_CASTLING) callback(board, flags, WhiteHSideCastleFR, 0, ff, 0, ft, closure);
1364 if(swap) callback(board, flags, WhiteHSideCastleFR, 0, ft, 0, ff, closure);
1367 ft = castlingRights[1]; /* Rook file if we have A-side rights */
1368 left = BOARD_LEFT+2;
1370 if(ff <= BOARD_LEFT+2) { left = ff+1; right = BOARD_LEFT+3; }
1371 for(k=left; k<=right && ft != NoRights; k++) /* first test if blocked */
1372 if(k != ft && board[0][k] != EmptySquare) ft = NoRights;
1373 if(ft == 0 && ff != 1 && board[0][1] != EmptySquare) ft = NoRights; /* Rook can be blocked on b1 */
1374 if(ff > BOARD_LEFT+2)
1375 for(k=left+1; k<=right && ft != NoRights; k++) /* then if not checked */
1376 if(!ignoreCheck && CheckTest(board, flags, 0, ff, 0, k, FALSE)) ft = NoRights;
1377 if(ft != NoRights && board[0][ft] == WhiteRook) {
1378 if(flags & F_FRC_TYPE_CASTLING) callback(board, flags, WhiteASideCastleFR, 0, ff, 0, ft, closure);
1379 if(swap) callback(board, flags, WhiteASideCastleFR, 0, ft, 0, ff, closure);
1383 ff = castlingRights[5]; /* King file if we have any rights */
1384 if(ff != NoRights && board[BOARD_HEIGHT-1][ff] == BlackKing) {
1385 ft = castlingRights[3]; /* Rook file if we have H-side rights */
1387 right = BOARD_RGHT-2;
1388 if(ff == BOARD_RGHT-2) left = right = ff-1; /* special case */
1389 for(k=left; k<=right && ft != NoRights; k++) /* first test if blocked */
1390 if(k != ft && board[BOARD_HEIGHT-1][k] != EmptySquare) ft = NoRights;
1391 for(k=left; k<right && ft != NoRights; k++) /* then if not checked */
1392 if(!ignoreCheck && CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, k, FALSE)) ft = NoRights;
1393 if(ft != NoRights && board[BOARD_HEIGHT-1][ft] == BlackRook) {
1394 if(flags & F_FRC_TYPE_CASTLING) callback(board, flags, BlackHSideCastleFR, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ft, closure);
1395 if(swap) callback(board, flags, BlackHSideCastleFR, BOARD_HEIGHT-1, ft, BOARD_HEIGHT-1, ff, closure);
1398 ft = castlingRights[4]; /* Rook file if we have A-side rights */
1399 left = BOARD_LEFT+2;
1401 if(ff <= BOARD_LEFT+2) { left = ff+1; right = BOARD_LEFT+3; }
1402 for(k=left; k<=right && ft != NoRights; k++) /* first test if blocked */
1403 if(k != ft && board[BOARD_HEIGHT-1][k] != EmptySquare) ft = NoRights;
1404 if(ft == 0 && ff != 1 && board[BOARD_HEIGHT-1][1] != EmptySquare) ft = NoRights; /* Rook can be blocked on b8 */
1405 if(ff > BOARD_LEFT+2)
1406 for(k=left+1; k<=right && ft != NoRights; k++) /* then if not checked */
1407 if(!ignoreCheck && CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, k, FALSE)) ft = NoRights;
1408 if(ft != NoRights && board[BOARD_HEIGHT-1][ft] == BlackRook) {
1409 if(flags & F_FRC_TYPE_CASTLING) callback(board, flags, BlackASideCastleFR, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ft, closure);
1410 if(swap) callback(board, flags, BlackASideCastleFR, BOARD_HEIGHT-1, ft, BOARD_HEIGHT-1, ff, closure);
1427 extern void CheckTestCallback P((Board board, int flags, ChessMove kind,
1428 int rf, int ff, int rt, int ft,
1433 CheckTestCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1435 register CheckTestClosure *cl = (CheckTestClosure *) closure;
1437 if (rt == cl->rking && ft == cl->fking) {
1438 if(xqCheckers[EP_STATUS] >= 2 && xqCheckers[rf][ff]) return; // checker is piece with suspended checking power
1440 xqCheckers[rf][ff] = xqCheckers[EP_STATUS] & 1; // remember who is checking (if status == 1)
1442 if( board[EP_STATUS] == EP_ROYAL_LION && (board[rt][ft] == WhiteLion || board[rt][ft] == BlackLion)
1443 && (gameInfo.variant != VariantLion || board[rf][ff] != WhiteKing && board[rf][ff] != BlackKing) )
1444 cl->check++; // [HGM] lion: forbidden counterstrike against Lion equated to putting yourself in check
1448 /* If the player on move were to move from (rf, ff) to (rt, ft), would
1449 he leave himself in check? Or if rf == -1, is the player on move
1450 in check now? enPassant must be TRUE if the indicated move is an
1451 e.p. capture. The possibility of castling out of a check along the
1452 back rank is not accounted for (i.e., we still return nonzero), as
1453 this is illegal anyway. Return value is the number of times the
1454 king is in check. */
1456 CheckTest (Board board, int flags, int rf, int ff, int rt, int ft, int enPassant)
1458 CheckTestClosure cl;
1459 ChessSquare king = flags & F_WHITE_ON_MOVE ? WhiteKing : BlackKing;
1460 ChessSquare captured = EmptySquare, ep=0, trampled=0;
1461 /* Suppress warnings on uninitialized variables */
1463 if(gameInfo.variant == VariantXiangqi)
1464 king = flags & F_WHITE_ON_MOVE ? WhiteWazir : BlackWazir;
1465 if(gameInfo.variant == VariantKnightmate)
1466 king = flags & F_WHITE_ON_MOVE ? WhiteUnicorn : BlackUnicorn;
1467 if(gameInfo.variant == VariantChu) { // strictly speaking this is not needed, as Chu officially has no check
1468 int r, f, k = king, royals=0, prince = flags & F_WHITE_ON_MOVE ? WhiteMonarch : BlackMonarch;
1469 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++) {
1470 if(board[r][f] == k || board[r][f] == prince) {
1471 if(++royals > 1) return FALSE; // no check if we have two royals (ignores double captureby Lion!)
1472 king = board[r][f]; // remember hich one we had
1479 captured = board[rf][ft];
1480 board[rf][ft] = EmptySquare;
1482 captured = board[rt][ft];
1483 if(killX >= 0) { trampled = board[killY][killX]; board[killY][killX] = EmptySquare; }
1485 if(rf == DROP_RANK) board[rt][ft] = ff; else { // [HGM] drop
1486 board[rt][ft] = board[rf][ff];
1487 board[rf][ff] = EmptySquare;
1489 ep = board[EP_STATUS];
1490 if( captured == WhiteLion || captured == BlackLion ) { // [HGM] lion: Chu Lion-capture rules
1491 ChessSquare victim = killX < 0 ? EmptySquare : trampled;
1492 if( (board[rt][ft] == WhiteLion || board[rt][ft] == BlackLion) && // capturer is Lion
1493 (ff - ft > 1 || ft - ff > 1 || rf - rt > 1 || rt - rf > 1) && // captures from a distance
1494 (victim == EmptySquare || victim == WhitePawn || victim == BlackPawn) ) // no or worthless 'bridge'
1495 board[EP_STATUS] = EP_ROYAL_LION; // on distant Lion x Lion victim must not be pseudo-legally protected
1499 /* For compatibility with ICS wild 9, we scan the board in the
1500 order a1, a2, a3, ... b1, b2, ..., h8 to find the first king,
1501 and we test only whether that one is in check. */
1502 for (cl.fking = BOARD_LEFT+0; cl.fking < BOARD_RGHT; cl.fking++)
1503 for (cl.rking = 0; cl.rking < BOARD_HEIGHT; cl.rking++) {
1504 if (board[cl.rking][cl.fking] == king) {
1506 if(gameInfo.variant == VariantXiangqi) {
1507 /* [HGM] In Xiangqi opposing Kings means check as well */
1509 dir = (king >= BlackPawn) ? -1 : 1;
1510 for( i=cl.rking+dir; i>=0 && i<BOARD_HEIGHT &&
1511 board[i][cl.fking] == EmptySquare; i+=dir );
1512 if(i>=0 && i<BOARD_HEIGHT &&
1513 board[i][cl.fking] == (dir>0 ? BlackWazir : WhiteWazir) )
1516 GenPseudoLegal(board, flags ^ F_WHITE_ON_MOVE, CheckTestCallback, (VOIDSTAR) &cl, EmptySquare);
1517 if(gameInfo.variant != VariantSpartan || cl.check == 0) // in Spartan Chess go on to test if other King is checked too
1518 goto undo_move; /* 2-level break */
1525 if(rf != DROP_RANK) // [HGM] drop
1526 board[rf][ff] = board[rt][ft];
1528 board[rf][ft] = captured;
1529 board[rt][ft] = EmptySquare;
1531 if(killX >= 0) board[killY][killX] = trampled;
1532 board[rt][ft] = captured;
1534 board[EP_STATUS] = ep;
1537 return cl.fking < BOARD_RGHT ? cl.check : 1000; // [HGM] atomic: return 1000 if we have no king
1541 HasLion (Board board, int flags)
1543 int lion = F_WHITE_ON_MOVE & flags ? WhiteLion : BlackLion;
1545 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++)
1546 if(board[r][f] == lion) return 1;
1551 LegalDrop (Board board, int flags, ChessSquare piece, int rt, int ft)
1552 { // [HGM] put drop legality testing in separate routine for clarity
1554 if(appData.debugMode) fprintf(debugFP, "LegalDrop: %d @ %d,%d)\n", piece, ft, rt);
1555 if(board[rt][ft] != EmptySquare) return ImpossibleMove; // must drop to empty square
1556 n = PieceToNumber(piece);
1557 if((gameInfo.holdingsWidth == 0 || (flags & F_WHITE_ON_MOVE ? board[n][BOARD_WIDTH-1] : board[BOARD_HEIGHT-1-n][0]) != piece)
1558 && gameInfo.variant != VariantBughouse) // in bughouse we don't check for availability, because ICS doesn't always tell us
1559 return ImpossibleMove; // piece not available
1560 if(gameInfo.variant == VariantShogi) { // in Shogi lots of drops are forbidden!
1561 if((piece == WhitePawn || piece == WhiteQueen) && rt == BOARD_HEIGHT-1 ||
1562 (piece == BlackPawn || piece == BlackQueen) && rt == 0 ||
1563 piece == WhiteKnight && rt > BOARD_HEIGHT-3 ||
1564 piece == BlackKnight && rt < 2 ) return IllegalMove; // e.g. where dropped piece has no moves
1565 if(piece == WhitePawn || piece == BlackPawn) {
1566 int r, max = 1 + (BOARD_HEIGHT == 7); // two Pawns per file in Tori!
1567 for(r=1; r<BOARD_HEIGHT-1; r++)
1568 if(!(max -= (board[r][ft] == piece))) return IllegalMove; // or there already is a Pawn in file
1569 // should still test if we mate with this Pawn
1571 } else if(gameInfo.variant == VariantSChess) { // only back-rank drops
1572 if (rt != (piece < BlackPawn ? 0 : BOARD_HEIGHT-1)) return IllegalMove;
1574 if( (piece == WhitePawn || piece == BlackPawn) &&
1575 (rt == 0 || rt == BOARD_HEIGHT -1 ) )
1576 return IllegalMove; /* no pawn drops on 1st/8th */
1578 if(appData.debugMode) fprintf(debugFP, "LegalDrop: %d @ %d,%d)\n", piece, ft, rt);
1579 if (!(flags & F_IGNORE_CHECK) &&
1580 CheckTest(board, flags, DROP_RANK, piece, rt, ft, FALSE) ) return IllegalMove;
1581 return flags & F_WHITE_ON_MOVE ? WhiteDrop : BlackDrop;
1584 extern void LegalityTestCallback P((Board board, int flags, ChessMove kind,
1585 int rf, int ff, int rt, int ft,
1589 LegalityTestCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1591 register LegalityTestClosure *cl = (LegalityTestClosure *) closure;
1593 if(board[rt][ft] != EmptySquare || kind==WhiteCapturesEnPassant || kind==BlackCapturesEnPassant)
1594 cl->captures++; // [HGM] losers: count legal captures
1595 if (rf == cl->rf && ff == cl->ff && rt == cl->rt && ft == cl->ft)
1600 LegalityTest (Board board, int flags, int rf, int ff, int rt, int ft, int promoChar)
1602 LegalityTestClosure cl; ChessSquare piece, filterPiece;
1604 if(quickFlag) flags = flags & ~1 | quickFlag & 1; // [HGM] speed: in quick mode quickFlag specifies side-to-move.
1605 if(rf == DROP_RANK) return LegalDrop(board, flags, ff, rt, ft);
1606 piece = filterPiece = board[rf][ff];
1607 if(PieceToChar(piece) == '~') filterPiece = DEMOTED piece;
1609 /* [HGM] Cobra and Falcon are wildcard pieces; consider all their moves legal */
1610 /* (perhaps we should disallow moves that obviously leave us in check?) */
1611 if((piece == WhiteFalcon || piece == BlackFalcon ||
1612 piece == WhiteCobra || piece == BlackCobra) && gameInfo.variant != VariantChu)
1613 return CheckTest(board, flags, rf, ff, rt, ft, FALSE) ? IllegalMove : NormalMove;
1617 cl.rt = rFilter = rt; // [HGM] speed: filter on to-square
1618 cl.ft = fFilter = ft;
1619 cl.kind = IllegalMove;
1620 cl.captures = 0; // [HGM] losers: prepare to count legal captures.
1621 if(flags & F_MANDATORY_CAPTURE) filterPiece = EmptySquare; // [HGM] speed: do not filter in suicide, to find all captures
1622 GenLegal(board, flags, LegalityTestCallback, (VOIDSTAR) &cl, filterPiece);
1623 if((flags & F_MANDATORY_CAPTURE) && cl.captures && board[rt][ft] == EmptySquare
1624 && cl.kind != WhiteCapturesEnPassant && cl.kind != BlackCapturesEnPassant)
1625 return(IllegalMove); // [HGM] losers: if there are legal captures, non-capts are illegal
1627 if(promoChar == 'x') promoChar = NULLCHAR; // [HGM] is this ever the case?
1628 if(gameInfo.variant == VariantSChess && promoChar && promoChar != '=' && board[rf][ff] != WhitePawn && board[rf][ff] != BlackPawn) {
1629 if(board[rf][ff] < BlackPawn) { // white
1630 if(rf != 0) return IllegalMove; // must be on back rank
1631 if(!(board[VIRGIN][ff] & VIRGIN_W)) return IllegalMove; // non-virgin
1632 if(board[PieceToNumber(CharToPiece(ToUpper(promoChar)))][BOARD_WIDTH-2] == 0) return ImpossibleMove;// must be in stock
1633 if(cl.kind == WhiteHSideCastleFR && (ff == BOARD_RGHT-2 || ff == BOARD_RGHT-3)) return ImpossibleMove;
1634 if(cl.kind == WhiteASideCastleFR && (ff == BOARD_LEFT+2 || ff == BOARD_LEFT+3)) return ImpossibleMove;
1636 if(rf != BOARD_HEIGHT-1) return IllegalMove;
1637 if(!(board[VIRGIN][ff] & VIRGIN_B)) return IllegalMove; // non-virgin
1638 if(board[BOARD_HEIGHT-1-PieceToNumber(CharToPiece(ToLower(promoChar)))][1] == 0) return ImpossibleMove;
1639 if(cl.kind == BlackHSideCastleFR && (ff == BOARD_RGHT-2 || ff == BOARD_RGHT-3)) return ImpossibleMove;
1640 if(cl.kind == BlackASideCastleFR && (ff == BOARD_LEFT+2 || ff == BOARD_LEFT+3)) return ImpossibleMove;
1643 if(gameInfo.variant == VariantChu) {
1644 if(cl.kind != NormalMove || promoChar == NULLCHAR || promoChar == '=') return cl.kind;
1645 if(promoChar != '+')
1646 return CharToPiece(promoChar) == EmptySquare ? ImpossibleMove : IllegalMove;
1647 if(PieceToChar(CHUPROMOTED board[rf][ff]) != '+') return ImpossibleMove;
1648 return flags & F_WHITE_ON_MOVE ? WhitePromotion : BlackPromotion;
1650 if(gameInfo.variant == VariantShogi) {
1651 /* [HGM] Shogi promotions. '=' means defer */
1652 if(rf != DROP_RANK && cl.kind == NormalMove) {
1653 ChessSquare piece = board[rf][ff];
1655 if(promoChar == PieceToChar(BlackQueen)) promoChar = NULLCHAR; /* [HGM] Kludge */
1656 if(promoChar == 'd' && (piece == WhiteRook || piece == BlackRook) ||
1657 promoChar == 'h' && (piece == WhiteBishop || piece == BlackBishop) ||
1658 promoChar == 'g' && (piece <= WhiteFerz || piece <= BlackFerz && piece >= BlackPawn) )
1659 promoChar = '+'; // allowed ICS notations
1660 if(appData.debugMode)fprintf(debugFP,"SHOGI promoChar = %c\n", promoChar ? promoChar : '-');
1661 if(promoChar != NULLCHAR && promoChar != '+' && promoChar != '=')
1662 return CharToPiece(promoChar) == EmptySquare ? ImpossibleMove : IllegalMove;
1663 else if(flags & F_WHITE_ON_MOVE) {
1664 if( (int) piece < (int) WhiteWazir &&
1665 (rf >= BOARD_HEIGHT - BOARD_HEIGHT/3 || rt >= BOARD_HEIGHT - BOARD_HEIGHT/3) ) {
1666 if( (piece == WhitePawn || piece == WhiteQueen) && rt > BOARD_HEIGHT-2 ||
1667 piece == WhiteKnight && rt > BOARD_HEIGHT-3) /* promotion mandatory */
1668 cl.kind = promoChar == '=' ? IllegalMove : WhitePromotion;
1669 else /* promotion optional, default is defer */
1670 cl.kind = promoChar == '+' ? WhitePromotion : WhiteNonPromotion;
1671 } else cl.kind = promoChar == '+' ? IllegalMove : NormalMove;
1673 if( (int) piece < (int) BlackWazir && (rf < BOARD_HEIGHT/3 || rt < BOARD_HEIGHT/3) ) {
1674 if( (piece == BlackPawn || piece == BlackQueen) && rt < 1 ||
1675 piece == BlackKnight && rt < 2 ) /* promotion obligatory */
1676 cl.kind = promoChar == '=' ? IllegalMove : BlackPromotion;
1677 else /* promotion optional, default is defer */
1678 cl.kind = promoChar == '+' ? BlackPromotion : BlackNonPromotion;
1679 } else cl.kind = promoChar == '+' ? IllegalMove : NormalMove;
1683 if (promoChar != NULLCHAR) {
1684 if(cl.kind == NormalMove && promoChar == '+') { // allow shogi-style promotion is pieceToChar specifies them
1685 ChessSquare piece = board[rf][ff];
1686 if(piece < BlackPawn ? piece > WhiteMan : piece > BlackMan) return ImpossibleMove; // already promoted
1687 // should test if in zone, really
1688 if(gameInfo.variant == VariantChuChess && (piece == WhiteKnight || piece == BlackKnight) && HasLion(board, flags))
1690 if(PieceToChar(PROMOTED piece) == '+') return flags & F_WHITE_ON_MOVE ? WhitePromotion : BlackPromotion;
1692 if(promoChar == '=') cl.kind = IllegalMove; else // [HGM] shogi: no deferred promotion outside Shogi
1693 if (cl.kind == WhitePromotion || cl.kind == BlackPromotion) {
1694 ChessSquare piece = CharToPiece(flags & F_WHITE_ON_MOVE ? ToUpper(promoChar) : ToLower(promoChar));
1695 if(piece == EmptySquare)
1696 cl.kind = ImpossibleMove; // non-existing piece
1697 if(gameInfo.variant == VariantChuChess && promoChar == 'l' && HasLion(board, flags)) {
1698 cl.kind = IllegalMove; // no two Lions
1699 } else if(gameInfo.variant == VariantSpartan && cl.kind == BlackPromotion ) {
1700 if(promoChar != PieceToChar(BlackKing)) {
1701 if(CheckTest(board, flags, rf, ff, rt, ft, FALSE)) cl.kind = IllegalMove; // [HGM] spartan: only promotion to King was possible
1702 if(piece == BlackLance) cl.kind = ImpossibleMove;
1703 } else { // promotion to King allowed only if we do not have two yet
1704 int r, f, kings = 0;
1705 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++) kings += (board[r][f] == BlackKing);
1706 if(kings == 2) cl.kind = IllegalMove;
1708 } else if(piece == WhitePawn && rt == BOARD_HEIGHT-1 ||
1709 piece == BlackPawn && rt == 0) cl.kind = IllegalMove; // cannot stay Pawn on last rank in any variant
1710 else if((piece == WhiteUnicorn || piece == BlackUnicorn) && gameInfo.variant == VariantKnightmate)
1711 cl.kind = IllegalMove; // promotion to Royal Knight not allowed
1712 else if((piece == WhiteKing || piece == BlackKing) && gameInfo.variant != VariantSuicide && gameInfo.variant != VariantGiveaway)
1713 cl.kind = IllegalMove; // promotion to King usually not allowed
1715 cl.kind = IllegalMove;
1725 extern void MateTestCallback P((Board board, int flags, ChessMove kind,
1726 int rf, int ff, int rt, int ft,
1730 MateTestCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1732 register MateTestClosure *cl = (MateTestClosure *) closure;
1737 /* Return MT_NONE, MT_CHECK, MT_CHECKMATE, or MT_STALEMATE */
1739 MateTest (Board board, int flags)
1742 int inCheck, r, f, myPieces=0, hisPieces=0, nrKing=0;
1743 ChessSquare king = flags & F_WHITE_ON_MOVE ? WhiteKing : BlackKing;
1745 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++) {
1746 // [HGM] losers: Count pieces and kings, to detect other unorthodox winning conditions
1747 nrKing += (board[r][f] == king); // stm has king
1748 if( board[r][f] != EmptySquare ) {
1749 if((int)board[r][f] <= (int)king && (int)board[r][f] >= (int)king - (int)WhiteKing + (int)WhitePawn)
1754 switch(gameInfo.variant) { // [HGM] losers: extinction wins
1755 case VariantShatranj:
1756 if(hisPieces == 1) return myPieces > 1 ? MT_BARE : MT_DRAW;
1760 if(nrKing == 0) return MT_NOKING;
1763 if(myPieces == 1) return MT_BARE;
1766 inCheck = GenLegal(board, flags, MateTestCallback, (VOIDSTAR) &cl, EmptySquare);
1767 // [HGM] 3check: yet to do!
1769 return inCheck ? MT_CHECK : MT_NONE;
1771 if(gameInfo.holdingsWidth && gameInfo.variant != VariantSuper && gameInfo.variant != VariantGreat
1772 && gameInfo.variant != VariantSChess && gameInfo.variant != VariantGrand) { // drop game
1773 int r, f, n, holdings = flags & F_WHITE_ON_MOVE ? BOARD_WIDTH-1 : 0;
1774 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++) if(board[r][f] == EmptySquare) // all empty squares
1775 for(n=0; n<BOARD_HEIGHT; n++) // all pieces in hand
1776 if(board[n][holdings] != EmptySquare) {
1777 int moveType = LegalDrop(board, flags, board[n][holdings], r, f);
1778 if(moveType == WhiteDrop || moveType == BlackDrop) return (inCheck ? MT_CHECK : MT_NONE); // we have legal drop
1781 if(gameInfo.variant == VariantSuicide) // [HGM] losers: always stalemate, since no check, but result varies
1782 return myPieces == hisPieces ? MT_STALEMATE :
1783 myPieces > hisPieces ? MT_STAINMATE : MT_STEALMATE;
1784 else if(gameInfo.variant == VariantLosers) return inCheck ? MT_TRICKMATE : MT_STEALMATE;
1785 else if(gameInfo.variant == VariantGiveaway) return MT_STEALMATE; // no check exists, stalemated = win
1787 return inCheck ? MT_CHECKMATE
1788 : (gameInfo.variant == VariantXiangqi || gameInfo.variant == VariantShatranj || IS_SHOGI(gameInfo.variant)) ?
1789 MT_STAINMATE : MT_STALEMATE;
1794 extern void DisambiguateCallback P((Board board, int flags, ChessMove kind,
1795 int rf, int ff, int rt, int ft,
1799 DisambiguateCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1801 register DisambiguateClosure *cl = (DisambiguateClosure *) closure;
1802 int wildCard = FALSE; ChessSquare piece = board[rf][ff];
1804 // [HGM] wild: for wild-card pieces rt and rf are dummies
1805 if(piece == WhiteFalcon || piece == BlackFalcon ||
1806 piece == WhiteCobra || piece == BlackCobra)
1809 if ((cl->pieceIn == EmptySquare || cl->pieceIn == board[rf][ff]
1810 || PieceToChar(board[rf][ff]) == '~'
1811 && cl->pieceIn == (ChessSquare)(DEMOTED board[rf][ff])
1813 (cl->rfIn == -1 || cl->rfIn == rf) &&
1814 (cl->ffIn == -1 || cl->ffIn == ff) &&
1815 (cl->rtIn == -1 || cl->rtIn == rt || wildCard) &&
1816 (cl->ftIn == -1 || cl->ftIn == ft || wildCard)) {
1818 if(cl->count && rf == cl->rf && ff == cl->ff) return; // duplicate move
1821 if(cl->count == 1 || board[rt][ft] != EmptySquare) {
1822 // [HGM] oneclick: if multiple moves, be sure we remember capture
1823 cl->piece = board[rf][ff];
1826 cl->rt = wildCard ? cl->rtIn : rt;
1827 cl->ft = wildCard ? cl->ftIn : ft;
1830 cl->captures += (board[rt][ft] != EmptySquare); // [HGM] oneclick: count captures
1835 Disambiguate (Board board, int flags, DisambiguateClosure *closure)
1837 int illegal = 0; char c = closure->promoCharIn;
1839 if(quickFlag) flags = flags & ~1 | quickFlag & 1; // [HGM] speed: in quick mode quickFlag specifies side-to-move.
1840 closure->count = closure->captures = 0;
1841 closure->rf = closure->ff = closure->rt = closure->ft = 0;
1842 closure->kind = ImpossibleMove;
1843 rFilter = closure->rtIn; // [HGM] speed: only consider moves to given to-square
1844 fFilter = closure->ftIn;
1845 if(quickFlag) { // [HGM] speed: try without check test first, because if that is not ambiguous, we are happy
1846 GenLegal(board, flags|F_IGNORE_CHECK, DisambiguateCallback, (VOIDSTAR) closure, closure->pieceIn);
1847 if(closure->count > 1) { // gamble did not pay off. retry with check test to resolve ambiguity
1848 closure->count = closure->captures = 0;
1849 closure->rf = closure->ff = closure->rt = closure->ft = 0;
1850 closure->kind = ImpossibleMove;
1851 GenLegal(board, flags, DisambiguateCallback, (VOIDSTAR) closure, closure->pieceIn); // [HGM] speed: only pieces of requested type
1854 GenLegal(board, flags, DisambiguateCallback, (VOIDSTAR) closure, closure->pieceIn); // [HGM] speed: only pieces of requested type
1855 if (closure->count == 0) {
1856 /* See if it's an illegal move due to check */
1858 GenLegal(board, flags|F_IGNORE_CHECK, DisambiguateCallback, (VOIDSTAR) closure, closure->pieceIn);
1859 if (closure->count == 0) {
1860 /* No, it's not even that */
1861 if(!appData.testLegality && closure->pieceIn != EmptySquare) {
1862 int f, r; // if there is only a single piece of the requested type on the board, use that
1863 closure->rt = closure->rtIn, closure->ft = closure->ftIn;
1864 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++)
1865 if(board[r][f] == closure->pieceIn) closure->count++, closure->rf = r, closure->ff = f;
1866 if(closure->count > 1) illegal = 0; // ambiguous
1868 if(closure->count == 0) {
1869 if (appData.debugMode) { int i, j;
1870 for(i=BOARD_HEIGHT-1; i>=0; i--) {
1871 for(j=0; j<BOARD_WIDTH; j++)
1872 fprintf(debugFP, "%3d", (int) board[i][j]);
1873 fprintf(debugFP, "\n");
1881 if (c == 'x') c = NULLCHAR; // get rid of any 'x' (which should never happen?)
1882 if(gameInfo.variant == VariantSChess && c && c != '=' && closure->piece != WhitePawn && closure->piece != BlackPawn) {
1883 if(closure->piece < BlackPawn) { // white
1884 if(closure->rf != 0) closure->kind = IllegalMove; // must be on back rank
1885 if(!(board[VIRGIN][closure->ff] & VIRGIN_W)) closure->kind = IllegalMove; // non-virgin
1886 if(board[PieceToNumber(CharToPiece(ToUpper(c)))][BOARD_WIDTH-2] == 0) closure->kind = ImpossibleMove;// must be in stock
1887 if(closure->kind == WhiteHSideCastleFR && (closure->ff == BOARD_RGHT-2 || closure->ff == BOARD_RGHT-3)) closure->kind = ImpossibleMove;
1888 if(closure->kind == WhiteASideCastleFR && (closure->ff == BOARD_LEFT+2 || closure->ff == BOARD_LEFT+3)) closure->kind = ImpossibleMove;
1890 if(closure->rf != BOARD_HEIGHT-1) closure->kind = IllegalMove;
1891 if(!(board[VIRGIN][closure->ff] & VIRGIN_B)) closure->kind = IllegalMove; // non-virgin
1892 if(board[BOARD_HEIGHT-1-PieceToNumber(CharToPiece(ToLower(c)))][1] == 0) closure->kind = ImpossibleMove;
1893 if(closure->kind == BlackHSideCastleFR && (closure->ff == BOARD_RGHT-2 || closure->ff == BOARD_RGHT-3)) closure->kind = ImpossibleMove;
1894 if(closure->kind == BlackASideCastleFR && (closure->ff == BOARD_LEFT+2 || closure->ff == BOARD_LEFT+3)) closure->kind = ImpossibleMove;
1897 if(gameInfo.variant == VariantChu) {
1898 if(c == '+') closure->kind = (flags & F_WHITE_ON_MOVE ? WhitePromotion : BlackPromotion); // for now, accept any
1900 if(gameInfo.variant == VariantShogi) {
1901 /* [HGM] Shogi promotions. On input, '=' means defer, '+' promote. Afterwards, c is set to '+' for promotions, NULL other */
1902 if(closure->rfIn != DROP_RANK && closure->kind == NormalMove) {
1903 ChessSquare piece = closure->piece;
1904 if (c == 'd' && (piece == WhiteRook || piece == BlackRook) ||
1905 c == 'h' && (piece == WhiteBishop || piece == BlackBishop) ||
1906 c == 'g' && (piece <= WhiteFerz || piece <= BlackFerz && piece >= BlackPawn) )
1907 c = '+'; // allowed ICS notations
1908 if(c != NULLCHAR && c != '+' && c != '=') closure->kind = IllegalMove; // otherwise specifying a piece is illegal
1909 else if(flags & F_WHITE_ON_MOVE) {
1910 if( (int) piece < (int) WhiteWazir &&
1911 (closure->rf >= BOARD_HEIGHT-(BOARD_HEIGHT/3) || closure->rt >= BOARD_HEIGHT-(BOARD_HEIGHT/3)) ) {
1912 if( (piece == WhitePawn || piece == WhiteQueen) && closure->rt > BOARD_HEIGHT-2 ||
1913 piece == WhiteKnight && closure->rt > BOARD_HEIGHT-3) /* promotion mandatory */
1914 closure->kind = c == '=' ? IllegalMove : WhitePromotion;
1915 else /* promotion optional, default is defer */
1916 closure->kind = c == '+' ? WhitePromotion : WhiteNonPromotion;
1917 } else closure->kind = c == '+' ? IllegalMove : NormalMove;
1919 if( (int) piece < (int) BlackWazir && (closure->rf < BOARD_HEIGHT/3 || closure->rt < BOARD_HEIGHT/3) ) {
1920 if( (piece == BlackPawn || piece == BlackQueen) && closure->rt < 1 ||
1921 piece == BlackKnight && closure->rt < 2 ) /* promotion obligatory */
1922 closure->kind = c == '=' ? IllegalMove : BlackPromotion;
1923 else /* promotion optional, default is defer */
1924 closure->kind = c == '+' ? BlackPromotion : BlackNonPromotion;
1925 } else closure->kind = c == '+' ? IllegalMove : NormalMove;
1928 if(closure->kind == WhitePromotion || closure->kind == BlackPromotion) c = '+'; else
1929 if(closure->kind == WhiteNonPromotion || closure->kind == BlackNonPromotion) c = '=';
1931 if (closure->kind == WhitePromotion || closure->kind == BlackPromotion) {
1932 if(c == NULLCHAR) { // missing promoChar on mandatory promotion; use default for variant
1933 if(gameInfo.variant == VariantShatranj || gameInfo.variant == VariantCourier ||
1934 gameInfo.variant == VariantMakruk || gameInfo.variant == VariantASEAN)
1935 c = PieceToChar(BlackFerz);
1936 else if(gameInfo.variant == VariantGreat)
1937 c = PieceToChar(BlackMan);
1938 else if(gameInfo.variant == VariantGrand)
1939 closure->kind = closure->rt != 0 && closure->rt != BOARD_HEIGHT-1 ? NormalMove : AmbiguousMove; // no default in Grand Chess
1941 c = PieceToChar(BlackQueen);
1942 } else if(c == '=') closure->kind = IllegalMove; // no deferral outside Shogi
1943 else if(c == 'l' && gameInfo.variant == VariantChuChess && HasLion(board, flags)) closure->kind = IllegalMove;
1944 } else if (c == '+') { // '+' outside shogi, check if pieceToCharTable enabled it
1945 ChessSquare p = closure->piece;
1946 if(p > WhiteMan && p < BlackPawn || p > BlackMan || PieceToChar(PROMOTED p) != '+')
1947 closure->kind = ImpossibleMove; // used on non-promotable piece
1948 else if(gameInfo.variant == VariantChuChess && HasLion(board, flags)) closure->kind = IllegalMove;
1949 } else if (c != NULLCHAR) closure->kind = IllegalMove;
1951 closure->promoChar = ToLower(c); // this can be NULLCHAR! Note we keep original promoChar even if illegal.
1952 if(c != '+' && c != '=' && c != NULLCHAR && CharToPiece(flags & F_WHITE_ON_MOVE ? ToUpper(c) : ToLower(c)) == EmptySquare)
1953 closure->kind = ImpossibleMove; // but we cannot handle non-existing piece types!
1954 if (closure->count > 1) {
1955 closure->kind = AmbiguousMove;
1958 /* Note: If more than one illegal move matches, but no legal
1959 moves, we return IllegalMove, not AmbiguousMove. Caller
1960 can look at closure->count to detect this.
1962 closure->kind = IllegalMove;
1976 } CoordsToAlgebraicClosure;
1978 extern void CoordsToAlgebraicCallback P((Board board, int flags,
1979 ChessMove kind, int rf, int ff,
1980 int rt, int ft, VOIDSTAR closure));
1983 CoordsToAlgebraicCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1985 register CoordsToAlgebraicClosure *cl =
1986 (CoordsToAlgebraicClosure *) closure;
1988 if ((rt == cl->rt && ft == cl->ft || rt == rf && ft == ff) && // [HGM] null move matches any toSquare
1989 (board[rf][ff] == cl->piece
1990 || PieceToChar(board[rf][ff]) == '~' &&
1991 (ChessSquare) (DEMOTED board[rf][ff]) == cl->piece)
1995 cl->kind = kind; /* this is the move we want */
1997 cl->file++; /* need file to rule out this move */
2001 cl->rank++; /* need rank to rule out this move */
2003 cl->either++; /* rank or file will rule out this move */
2009 /* Convert coordinates to normal algebraic notation.
2010 promoChar must be NULLCHAR or 'x' if not a promotion.
2013 CoordsToAlgebraic (Board board, int flags, int rf, int ff, int rt, int ft, int promoChar, char out[MOVE_LEN])
2017 char *outp = out, c, capture;
2018 CoordsToAlgebraicClosure cl;
2020 if (rf == DROP_RANK) {
2021 if(ff == EmptySquare) { strncpy(outp, "--",3); return NormalMove; } // [HGM] pass
2022 /* Bughouse piece drop */
2023 *outp++ = ToUpper(PieceToChar((ChessSquare) ff));
2028 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2030 return (flags & F_WHITE_ON_MOVE) ? WhiteDrop : BlackDrop;
2033 if (promoChar == 'x') promoChar = NULLCHAR;
2034 piece = board[rf][ff];
2035 if(PieceToChar(piece)=='~') piece = (ChessSquare)(DEMOTED piece);
2040 kind = LegalityTest(board, flags, rf, ff, rt, ft, promoChar);
2041 if (kind == IllegalMove && !(flags&F_IGNORE_CHECK)) {
2042 /* Keep short notation if move is illegal only because it
2043 leaves the player in check, but still return IllegalMove */
2044 kind = LegalityTest(board, flags|F_IGNORE_CHECK, rf, ff, rt, ft, promoChar);
2045 if (kind == IllegalMove) break;
2050 capture = board[rt][ft] != EmptySquare || kind == WhiteCapturesEnPassant || kind == BlackCapturesEnPassant;
2051 if (ff == ft && !capture) { /* [HGM] Xiangqi has straight noncapts! */
2052 /* Non-capture; use style "e5" */
2055 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2057 /* Capture; use style "exd5" */
2059 *outp++ = 'x'; /* [HGM] Xiangqi has sideway noncaptures across river! */
2063 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2065 /* Use promotion suffix style "=Q" */
2067 if (promoChar != NULLCHAR) {
2068 if(IS_SHOGI(gameInfo.variant)) {
2069 /* [HGM] ... but not in Shogi! */
2070 *outp++ = promoChar == '=' ? '=' : '+';
2073 *outp++ = ToUpper(promoChar);
2082 /* Fabien moved code: FRC castling first (if KxR), wild castling second */
2083 /* Code added by Tord: FRC castling. */
2084 if((piece == WhiteKing && board[rt][ft] == WhiteRook) ||
2085 (piece == BlackKing && board[rt][ft] == BlackRook)) {
2087 safeStrCpy(out, "O-O", MOVE_LEN);
2089 safeStrCpy(out, "O-O-O", MOVE_LEN);
2090 return LegalityTest(board, flags, rf, ff, rt, ft, promoChar);
2092 /* End of code added by Tord */
2093 /* Test for castling or ICS wild castling */
2094 /* Use style "O-O" (oh-oh) for PGN compatibility */
2095 else if (rf == rt &&
2096 rf == ((piece == WhiteKing) ? 0 : BOARD_HEIGHT-1) &&
2097 (ft - ff > 1 || ff - ft > 1) && // No castling if legal King move (on narrow boards!)
2098 ((ff == BOARD_WIDTH>>1 && (ft == BOARD_LEFT+2 || ft == BOARD_RGHT-2)) ||
2099 (ff == (BOARD_WIDTH-1)>>1 && (ft == BOARD_LEFT+1 || ft == BOARD_RGHT-3)))) {
2100 if(ft==BOARD_LEFT+1 || ft==BOARD_RGHT-2)
2101 snprintf(out, MOVE_LEN, "O-O%c%c", promoChar ? '/' : 0, ToUpper(promoChar));
2103 snprintf(out, MOVE_LEN, "O-O-O%c%c", promoChar ? '/' : 0, ToUpper(promoChar));
2105 /* This notation is always unambiguous, unless there are
2106 kings on both the d and e files, with "wild castling"
2107 possible for the king on the d file and normal castling
2108 possible for the other. ICS rules for wild 9
2109 effectively make castling illegal for either king in
2110 this situation. So I am not going to worry about it;
2111 I'll just generate an ambiguous O-O in this case.
2113 return LegalityTest(board, flags, rf, ff, rt, ft, promoChar);
2116 /* else fall through */
2121 cl.rt = rFilter = rt; // [HGM] speed: filter on to-square
2122 cl.ft = fFilter = ft;
2124 cl.kind = IllegalMove;
2125 cl.rank = cl.file = cl.either = 0;
2126 c = PieceToChar(piece) ;
2127 GenLegal(board, flags, CoordsToAlgebraicCallback, (VOIDSTAR) &cl, c!='~' ? piece : (DEMOTED piece)); // [HGM] speed
2129 if (cl.kind == IllegalMove && !(flags&F_IGNORE_CHECK)) {
2130 /* Generate pretty moves for moving into check, but
2131 still return IllegalMove.
2133 GenLegal(board, flags|F_IGNORE_CHECK, CoordsToAlgebraicCallback, (VOIDSTAR) &cl, c!='~' ? piece : (DEMOTED piece));
2134 if (cl.kind == IllegalMove) break;
2135 cl.kind = IllegalMove;
2138 /* Style is "Nf3" or "Nxf7" if this is unambiguous,
2139 else "Ngf3" or "Ngxf7",
2140 else "N1f3" or "N5xf7",
2141 else "Ng1f3" or "Ng5xf7".
2143 if( c == '~' || c == '+') {
2144 /* [HGM] print nonexistent piece as its demoted version */
2145 piece = (ChessSquare) (DEMOTED piece - 11*(gameInfo.variant == VariantChu));
2147 if(c=='+') *outp++ = c;
2148 *outp++ = ToUpper(PieceToChar(piece));
2150 if (cl.file || (cl.either && !cl.rank)) {
2156 else { *outp++ = (rf+ONE-'0')/10 + '0';*outp++ = (rf+ONE-'0')%10 + '0'; }
2159 if(board[rt][ft] != EmptySquare)
2165 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2166 if (IS_SHOGI(gameInfo.variant)) {
2167 /* [HGM] in Shogi non-pawns can promote */
2168 *outp++ = promoChar; // Don't bother to correct move type, return value is never used!
2170 else if (gameInfo.variant == VariantChuChess && promoChar ||
2171 gameInfo.variant != VariantSuper && promoChar &&
2172 (piece == WhiteLance || piece == BlackLance) ) { // Lance sometimes represents Pawn
2174 *outp++ = ToUpper(promoChar);
2176 else if (gameInfo.variant == VariantSChess && promoChar) { // and in S-Chess we have gating
2178 *outp++ = ToUpper(promoChar);
2184 /* Moving a nonexistent piece */
2188 /* Not a legal move, even ignoring check.
2189 If there was a piece on the from square,
2190 use style "Ng1g3" or "Ng1xe8";
2191 if there was a pawn or nothing (!),
2192 use style "g1g3" or "g1xe8". Use "x"
2193 if a piece was on the to square, even
2194 a piece of the same color.
2198 if (piece != EmptySquare && piece != WhitePawn && piece != BlackPawn) {
2200 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<=BOARD_RGHT; f++)
2201 c += (board[r][f] == piece); // count on-board pieces of given type
2202 *outp++ = ToUpper(PieceToChar(piece));
2204 if(c != 1) { // [HGM] but if there is only one piece of the mentioned type, no from-square, thank you!
2208 else { *outp++ = (rf+ONE-'0')/10 + '0';*outp++ = (rf+ONE-'0')%10 + '0'; }
2210 if (board[rt][ft] != EmptySquare) *outp++ = 'x';
2214 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2215 /* Use promotion suffix style "=Q" */
2216 if (promoChar != NULLCHAR && promoChar != 'x') {
2218 *outp++ = ToUpper(promoChar);
2225 // [HGM] XQ: the following code serves to detect perpetual chasing (Asian rules)
2234 // I guess the following variables logically belong in the closure too, but I was too lazy and used globals
2236 int preyStackPointer, chaseStackPointer;
2239 unsigned char rf, ff, rt, ft;
2243 unsigned char rank, file;
2249 // there are three new callbacks for use with GenLegal: for adding captures, deleting them, and finding a recapture
2251 extern void AtacksCallback P((Board board, int flags, ChessMove kind,
2252 int rf, int ff, int rt, int ft,
2256 AttacksCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
2257 { // For adding captures that can lead to chase indictment to the chaseStack
2258 if(board[rt][ft] == EmptySquare) return; // non-capture
2259 if(board[rt][ft] == WhitePawn && rt < BOARD_HEIGHT/2) return; // Pawn before river can be chased
2260 if(board[rt][ft] == BlackPawn && rt >= BOARD_HEIGHT/2) return; // Pawn before river can be chased
2261 if(board[rf][ff] == WhitePawn || board[rf][ff] == BlackPawn) return; // Pawns are allowed to chase
2262 if(board[rf][ff] == WhiteWazir || board[rf][ff] == BlackWazir) return; // King is allowed to chase
2263 // move cannot be excluded from being a chase trivially (based on attacker and victim); save it on chaseStack
2264 chaseStack[chaseStackPointer].rf = rf;
2265 chaseStack[chaseStackPointer].ff = ff;
2266 chaseStack[chaseStackPointer].rt = rt;
2267 chaseStack[chaseStackPointer].ft = ft;
2268 chaseStackPointer++;
2271 extern void ExistingAtacksCallback P((Board board, int flags, ChessMove kind,
2272 int rf, int ff, int rt, int ft,
2276 ExistingAttacksCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
2277 { // for removing pre-exsting captures from the chaseStack, to be left with newly created ones
2279 register ChaseClosure *cl = (ChaseClosure *) closure; //closure tells us the move played in the repeat loop
2281 if(board[rt][ft] == EmptySquare) return; // no capture
2282 if(rf == cl->rf && ff == cl->ff) { // attacks with same piece from new position are not considered new
2283 rf = cl->rt; ff = cl->ft; // doctor their fromSquare so they will be recognized in chaseStack
2285 // search move in chaseStack, and delete it if it occurred there (as we know now it is not a new capture)
2286 for(i=0; i<chaseStackPointer; i++) {
2287 if(chaseStack[i].rf == rf && chaseStack[i].ff == ff &&
2288 chaseStack[i].rt == rt && chaseStack[i].ft == ft ) {
2289 // move found on chaseStack, delete it by overwriting with move popped from top of chaseStack
2290 chaseStack[i] = chaseStack[--chaseStackPointer];
2296 extern void ProtectedCallback P((Board board, int flags, ChessMove kind,
2297 int rf, int ff, int rt, int ft,
2301 ProtectedCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
2302 { // for determining if a piece (given through the closure) is protected
2303 register ChaseClosure *cl = (ChaseClosure *) closure; // closure tells us where to recapture
2305 if(rt == cl->rt && ft == cl->ft) cl->recaptures++; // count legal recaptures to this square
2306 if(appData.debugMode && board[rt][ft] != EmptySquare)
2307 fprintf(debugFP, "try %c%c%c%c=%d\n", ff+AAA, rf+ONE,ft+AAA, rt+ONE, cl->recaptures);
2310 extern char moveList[MAX_MOVES][MOVE_LEN];
2313 PerpetualChase (int first, int last)
2314 { // this routine detects if the side to move in the 'first' position is perpetually chasing (when not checking)
2317 ChessSquare captured;
2319 preyStackPointer = 0; // clear stack of chased pieces
2320 for(i=first; i<last; i+=2) { // for all positions with same side to move
2321 if(appData.debugMode) fprintf(debugFP, "judge position %i\n", i);
2322 chaseStackPointer = 0; // clear stack that is going to hold possible chases
2323 // determine all captures possible after the move, and put them on chaseStack
2324 GenLegal(boards[i+1], PosFlags(i), AttacksCallback, &cl, EmptySquare);
2325 if(appData.debugMode) { int n;
2326 for(n=0; n<chaseStackPointer; n++)
2327 fprintf(debugFP, "%c%c%c%c ", chaseStack[n].ff+AAA, chaseStack[n].rf+ONE,
2328 chaseStack[n].ft+AAA, chaseStack[n].rt+ONE);
2329 fprintf(debugFP, ": all capts\n");
2331 // determine all captures possible before the move, and delete them from chaseStack
2332 cl.rf = moveList[i][1]-ONE; // prepare closure to pass move that led from i to i+1
2333 cl.ff = moveList[i][0]-AAA+BOARD_LEFT;
2334 cl.rt = moveList[i][3]-ONE;
2335 cl.ft = moveList[i][2]-AAA+BOARD_LEFT;
2336 CopyBoard(xqCheckers, nullBoard); xqCheckers[EP_STATUS] = 1; // giant kludge to make GenLegal ignore pre-existing checks
2337 GenLegal(boards[i], PosFlags(i), ExistingAttacksCallback, &cl, EmptySquare);
2338 xqCheckers[EP_STATUS] = 0; // disable the generation of quasi-legal moves again
2339 if(appData.debugMode) { int n;
2340 for(n=0; n<chaseStackPointer; n++)
2341 fprintf(debugFP, "%c%c%c%c ", chaseStack[n].ff+AAA, chaseStack[n].rf+ONE,
2342 chaseStack[n].ft+AAA, chaseStack[n].rt+ONE);
2343 fprintf(debugFP, ": new capts after %c%c%c%c\n", cl.ff+AAA, cl.rf+ONE, cl.ft+AAA, cl.rt+ONE);
2345 // chaseSack now contains all captures made possible by the move
2346 for(j=0; j<chaseStackPointer; j++) { // run through chaseStack to identify true chases
2347 int attacker = (int)boards[i+1][chaseStack[j].rf][chaseStack[j].ff];
2348 int victim = (int)boards[i+1][chaseStack[j].rt][chaseStack[j].ft];
2350 if(attacker >= (int) BlackPawn) attacker = BLACK_TO_WHITE attacker; // convert to white, as piecee type
2351 if(victim >= (int) BlackPawn) victim = BLACK_TO_WHITE victim;
2353 if((attacker == WhiteKnight || attacker == WhiteCannon) && victim == WhiteRook)
2354 continue; // C or H attack on R is always chase; leave on chaseStack
2356 if(attacker == victim) {
2357 if(LegalityTest(boards[i+1], PosFlags(i+1), chaseStack[j].rt,
2358 chaseStack[j].ft, chaseStack[j].rf, chaseStack[j].ff, NULLCHAR) == NormalMove) {
2359 // we can capture back with equal piece, so this is no chase but a sacrifice
2360 chaseStack[j] = chaseStack[--chaseStackPointer]; // delete the capture from the chaseStack
2361 j--; /* ! */ continue;
2366 // the attack is on a lower piece, or on a pinned or blocked equal one
2367 CopyBoard(xqCheckers, nullBoard); xqCheckers[EP_STATUS] = 1;
2368 CheckTest(boards[i+1], PosFlags(i+1), -1, -1, -1, -1, FALSE); // if we deliver check with our move, the checkers get marked
2369 // test if the victim is protected by a true protector. First make the capture.
2370 captured = boards[i+1][chaseStack[j].rt][chaseStack[j].ft];
2371 boards[i+1][chaseStack[j].rt][chaseStack[j].ft] = boards[i+1][chaseStack[j].rf][chaseStack[j].ff];
2372 boards[i+1][chaseStack[j].rf][chaseStack[j].ff] = EmptySquare;
2373 // Then test if the opponent can recapture
2374 cl.recaptures = 0; // prepare closure to pass recapture square and count moves to it
2375 cl.rt = chaseStack[j].rt;
2376 cl.ft = chaseStack[j].ft;
2377 if(appData.debugMode) {
2378 fprintf(debugFP, "test if we can recapture %c%c\n", cl.ft+AAA, cl.rt+ONE);
2380 xqCheckers[EP_STATUS] = 2; // causes GenLegal to ignore the checks we delivered with the move, in real life evaded before we captured
2381 GenLegal(boards[i+1], PosFlags(i+1), ProtectedCallback, &cl, EmptySquare); // try all moves
2382 xqCheckers[EP_STATUS] = 0; // disable quasi-legal moves again
2383 // unmake the capture
2384 boards[i+1][chaseStack[j].rf][chaseStack[j].ff] = boards[i+1][chaseStack[j].rt][chaseStack[j].ft];
2385 boards[i+1][chaseStack[j].rt][chaseStack[j].ft] = captured;
2386 // if a recapture was found, piece is protected, and we are not chasing it.
2387 if(cl.recaptures) { // attacked piece was defended by true protector, no chase
2388 chaseStack[j] = chaseStack[--chaseStackPointer]; // so delete from chaseStack
2392 // chaseStack now contains all moves that chased
2393 if(appData.debugMode) { int n;
2394 for(n=0; n<chaseStackPointer; n++)
2395 fprintf(debugFP, "%c%c%c%c ", chaseStack[n].ff+AAA, chaseStack[n].rf+ONE,
2396 chaseStack[n].ft+AAA, chaseStack[n].rt+ONE);
2397 fprintf(debugFP, ": chases\n");
2399 if(i == first) { // copy all people chased by first move of repeat cycle to preyStack
2400 for(j=0; j<chaseStackPointer; j++) {
2401 preyStack[j].rank = chaseStack[j].rt;
2402 preyStack[j].file = chaseStack[j].ft;
2404 preyStackPointer = chaseStackPointer;
2407 for(j=0; j<chaseStackPointer; j++) {
2408 for(k=0; k<preyStackPointer; k++) {
2409 // search the victim of each chase move on the preyStack (first occurrence)
2410 if(chaseStack[j].ft == preyStack[k].file && chaseStack[j].rt == preyStack[k].rank ) {
2411 if(k < tail) break; // piece was already identified as still being chased
2412 preyStack[preyStackPointer] = preyStack[tail]; // move chased piece to bottom part of preyStack
2413 preyStack[tail] = preyStack[k]; // by swapping
2414 preyStack[k] = preyStack[preyStackPointer];
2420 preyStackPointer = tail; // keep bottom part of preyStack, popping pieces unchased on move i.
2421 if(appData.debugMode) { int n;
2422 for(n=0; n<preyStackPointer; n++)
2423 fprintf(debugFP, "%c%c ", preyStack[n].file+AAA, preyStack[n].rank+ONE);
2424 fprintf(debugFP, "always chased upto ply %d\n", i);
2426 // now adjust the location of the chased pieces according to opponent move
2427 for(j=0; j<preyStackPointer; j++) {
2428 if(preyStack[j].rank == moveList[i+1][1]-ONE &&
2429 preyStack[j].file == moveList[i+1][0]-AAA+BOARD_LEFT) {
2430 preyStack[j].rank = moveList[i+1][3]-ONE;
2431 preyStack[j].file = moveList[i+1][2]-AAA+BOARD_LEFT;
2436 return preyStackPointer ? 256*(preyStack[preyStackPointer].file - BOARD_LEFT + AAA) + (preyStack[preyStackPointer].rank + ONE)
2437 : 0; // if any piece was left on preyStack, it has been perpetually chased,and we return the