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(*desc == 'n') jump = 0, desc++;
251 while(*desc == 'j') jump++, desc++;
252 if(!mode) mode = his + 4;// no mode spec, use default = mc
253 dx = xStep[*p-'A'] - '0'; // step vector of atom
254 dy = yStep[*p-'A'] - '0';
255 if(isdigit(*++p)) expo = atoi(p++); // read exponent
256 if(expo > 9) p++; // allow double-digit
257 desc = p; // this is start of next move
258 if(initial && board[r][f] != initialPosition[r][f]) continue;
260 for(dir=0, bit=1; dir<8; dir++, bit += bit) { // loop over directions
261 int i = expo, vx, vy;
262 if(!(bit & dirSet)) continue; // does not move in this direction
263 vx = dx*rot[dir][0] + dy*rot[dir][1]; // rotate step vector
264 vy = dx*rot[dir][2] + dy*rot[dir][3];
265 x = f; y = r; // start square
267 x += vx; y += vy; // step to next square
268 if(y < 0 || y >= BOARD_HEIGHT || x < BOARD_LEFT || x >= BOARD_RGHT) break;
269 if(!jump && board[y - vy + vy/2][x - vx + vx/2] != EmptySquare) break; // blocked
270 if(jump > 1 && board[y - vy + vy/2][x - vx + vx/2] == EmptySquare) break; // no hop
271 if(board[y][x] < BlackPawn) occup = 1; else
272 if(board[y][x] < EmptySquare) occup = 2; else
274 if(mode & 8 && y == board[EP_RANK] && occup == 4 && board[EP_FILE] == x) { // to e.p. square
275 cb(board, flags, mine == 1 ? WhiteCapturesEnPassant : BlackCapturesEnPassant, r, f, y, x, cl);
277 if(occup & mode) cb(board, flags, NormalMove, r, f, y, x, cl); // allowed, generate
278 if(occup != 4) break; // not valid transit square
281 dx = dy = 1; dirSet = 0x99; // prepare for diagonal moves of K,Q
282 } while(retry--); // and start doing them
286 // [HGM] move generation now based on hierarchy of subroutines for rays and combinations of rays
289 SlideForward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
294 if (rt >= BOARD_HEIGHT) break;
295 if (SameColor(board[rf][ff], board[rt][ft])) break;
296 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
297 if (board[rt][ft] != EmptySquare) break;
302 SlideBackward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
308 if (SameColor(board[rf][ff], board[rt][ft])) break;
309 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
310 if (board[rt][ft] != EmptySquare) break;
315 SlideVertical (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
317 SlideForward(board, flags, rf, ff, callback, closure);
318 SlideBackward(board, flags, rf, ff, callback, closure);
322 SlideSideways (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
324 int i, s, rt = rf, ft;
325 for(s = -1; s <= 1; s+= 2) {
328 if (ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
329 if (SameColor(board[rf][ff], board[rt][ft])) break;
330 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
331 if (board[rt][ft] != EmptySquare) break;
337 SlideDiagForward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
340 for(s = -1; s <= 1; s+= 2) {
344 if (rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
345 if (SameColor(board[rf][ff], board[rt][ft])) break;
346 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
347 if (board[rt][ft] != EmptySquare) break;
353 SlideDiagBackward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
356 for(s = -1; s <= 1; s+= 2) {
360 if (rt < 0 || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
361 if (SameColor(board[rf][ff], board[rt][ft])) break;
362 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
363 if (board[rt][ft] != EmptySquare) break;
369 Rook (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
371 SlideVertical(board, flags, rf, ff, callback, closure);
372 SlideSideways(board, flags, rf, ff, callback, closure);
376 Bishop (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
378 SlideDiagForward(board, flags, rf, ff, callback, closure);
379 SlideDiagBackward(board, flags, rf, ff, callback, closure);
383 Sting (Board board, int flags, int rf, int ff, int dy, int dx, MoveCallback callback, VOIDSTAR closure)
384 { // Lion-like move of Horned Falcon and Souring Eagle
385 int ft = ff + dx, rt = rf + dy;
386 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) return;
387 if (!SameColor(board[rf][ff], board[rt][ft]))
388 callback(board, flags, board[rt][ft] != EmptySquare ? FirstLeg : NormalMove, rf, ff, rt, ft, closure);
390 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) return;
391 if (!SameColor(board[rf][ff], board[rt][ft]))
392 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
396 StepForward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
398 int ft = ff, rt = rf + 1;
399 if (rt >= BOARD_HEIGHT) return;
400 if (SameColor(board[rf][ff], board[rt][ft])) return;
401 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
405 StepBackward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
407 int ft = ff, rt = rf - 1;
409 if (SameColor(board[rf][ff], board[rt][ft])) return;
410 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
414 StepSideways (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
418 if (!(rt >= BOARD_HEIGHT || ft >= BOARD_RGHT) && !SameColor(board[rf][ff], board[rt][ft]))
419 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
421 if (!(rt >= BOARD_HEIGHT || ft < BOARD_LEFT) && !SameColor(board[rf][ff], board[rt][ft]))
422 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
426 StepDiagForward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
429 if (rt >= BOARD_HEIGHT) return;
431 if (!(rt >= BOARD_HEIGHT || ft >= BOARD_RGHT) && !SameColor(board[rf][ff], board[rt][ft]))
432 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
434 if (!(rt >= BOARD_HEIGHT || ft < BOARD_LEFT) && !SameColor(board[rf][ff], board[rt][ft]))
435 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
439 StepDiagBackward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
444 if (!(rt < 0 || ft >= BOARD_RGHT) && !SameColor(board[rf][ff], board[rt][ft]))
445 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
447 if (!(rt < 0 || ft < BOARD_LEFT) && !SameColor(board[rf][ff], board[rt][ft]))
448 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
452 StepVertical (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
454 StepForward(board, flags, rf, ff, callback, closure);
455 StepBackward(board, flags, rf, ff, callback, closure);
459 Ferz (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
461 StepDiagForward(board, flags, rf, ff, callback, closure);
462 StepDiagBackward(board, flags, rf, ff, callback, closure);
466 Wazir (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
468 StepVertical(board, flags, rf, ff, callback, closure);
469 StepSideways(board, flags, rf, ff, callback, closure);
473 Knight (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
476 for (i = -1; i <= 1; i += 2)
477 for (j = -1; j <= 1; j += 2)
478 for (s = 1; s <= 2; s++) {
481 if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
482 && ( gameInfo.variant != VariantXiangqi || board[rf+i*(s-1)][ff+j*(2-s)] == EmptySquare)
483 && !SameColor(board[rf][ff], board[rt][ft]))
484 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
488 /* Call callback once for each pseudo-legal move in the given
489 position, except castling moves. A move is pseudo-legal if it is
490 legal, or if it would be legal except that it leaves the king in
491 check. In the arguments, epfile is EP_NONE if the previous move
492 was not a double pawn push, or the file 0..7 if it was, or
493 EP_UNKNOWN if we don't know and want to allow all e.p. captures.
494 Promotion moves generated are to Queen only.
497 GenPseudoLegal (Board board, int flags, MoveCallback callback, VOIDSTAR closure, ChessSquare filter)
498 // speed: only do moves with this piece type
501 int i, j, d, s, fs, rs, rt, ft, m;
502 int epfile = (signed char)board[EP_STATUS]; // [HGM] gamestate: extract ep status from board
503 int promoRank = gameInfo.variant == VariantMakruk || gameInfo.variant == VariantGrand || gameInfo.variant == VariantChuChess ? 3 : 1;
505 for (rf = 0; rf < BOARD_HEIGHT; rf++)
506 for (ff = BOARD_LEFT; ff < BOARD_RGHT; ff++) {
509 if(board[rf][ff] == EmptySquare) continue;
510 if ((flags & F_WHITE_ON_MOVE) != (board[rf][ff] < BlackPawn)) continue; // [HGM] speed: wrong color
511 m = 0; piece = board[rf][ff];
512 if(PieceToChar(piece) == '~')
513 piece = (ChessSquare) ( DEMOTED piece );
514 if(filter != EmptySquare && piece != filter) continue;
515 if(pieceDesc[piece]) { MovesFromString(board, flags, ff, rf, pieceDesc[piece], callback, closure); continue; } // [HGM] gen
516 if(IS_SHOGI(gameInfo.variant))
517 piece = (ChessSquare) ( SHOGI piece );
519 switch ((int)piece) {
520 /* case EmptySquare: [HGM] this is nonsense, and conflicts with Shogi cases */
522 /* can't happen ([HGM] except for faries...) */
526 if(gameInfo.variant == VariantXiangqi) {
527 /* [HGM] capture and move straight ahead in Xiangqi */
528 if (rf < BOARD_HEIGHT-1 &&
529 !SameColor(board[rf][ff], board[rf + 1][ff]) ) {
530 callback(board, flags, NormalMove,
531 rf, ff, rf + 1, ff, closure);
533 /* and move sideways when across the river */
534 for (s = -1; s <= 1; s += 2) {
535 if (rf >= BOARD_HEIGHT>>1 &&
536 ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
537 !WhitePiece(board[rf][ff+s]) ) {
538 callback(board, flags, NormalMove,
539 rf, ff, rf, ff+s, closure);
544 if (rf < BOARD_HEIGHT-1 && board[rf + 1][ff] == EmptySquare) {
545 callback(board, flags,
546 rf >= BOARD_HEIGHT-1-promoRank ? WhitePromotion : NormalMove,
547 rf, ff, rf + 1, ff, closure);
549 if (rf <= (BOARD_HEIGHT>>1)-3 && board[rf+1][ff] == EmptySquare && // [HGM] grand: also on 3rd rank on 10-board
550 gameInfo.variant != VariantShatranj && /* [HGM] */
551 gameInfo.variant != VariantCourier && /* [HGM] */
552 board[rf+2][ff] == EmptySquare ) {
553 callback(board, flags, NormalMove,
554 rf, ff, rf+2, ff, closure);
556 for (s = -1; s <= 1; s += 2) {
557 if (rf < BOARD_HEIGHT-1 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
558 ((flags & F_KRIEGSPIEL_CAPTURE) ||
559 BlackPiece(board[rf + 1][ff + s]))) {
560 callback(board, flags,
561 rf >= BOARD_HEIGHT-1-promoRank ? WhitePromotion : NormalMove,
562 rf, ff, rf + 1, ff + s, closure);
564 if (rf >= BOARD_HEIGHT+1>>1) {// [HGM] grand: 4th & 5th rank on 10-board
565 if (ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
566 (epfile == ff + s || epfile == EP_UNKNOWN) && rf < BOARD_HEIGHT-3 &&
567 board[rf][ff + s] == BlackPawn &&
568 board[rf+1][ff + s] == EmptySquare) {
569 callback(board, flags, WhiteCapturesEnPassant,
570 rf, ff, rf+1, ff + s, closure);
577 if(gameInfo.variant == VariantXiangqi) {
578 /* [HGM] capture straight ahead in Xiangqi */
579 if (rf > 0 && !SameColor(board[rf][ff], board[rf - 1][ff]) ) {
580 callback(board, flags, NormalMove,
581 rf, ff, rf - 1, ff, closure);
583 /* and move sideways when across the river */
584 for (s = -1; s <= 1; s += 2) {
585 if (rf < BOARD_HEIGHT>>1 &&
586 ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
587 !BlackPiece(board[rf][ff+s]) ) {
588 callback(board, flags, NormalMove,
589 rf, ff, rf, ff+s, closure);
594 if (rf > 0 && board[rf - 1][ff] == EmptySquare) {
595 callback(board, flags,
596 rf <= promoRank ? BlackPromotion : NormalMove,
597 rf, ff, rf - 1, ff, closure);
599 if (rf >= (BOARD_HEIGHT+1>>1)+2 && board[rf-1][ff] == EmptySquare && // [HGM] grand
600 gameInfo.variant != VariantShatranj && /* [HGM] */
601 gameInfo.variant != VariantCourier && /* [HGM] */
602 board[rf-2][ff] == EmptySquare) {
603 callback(board, flags, NormalMove,
604 rf, ff, rf-2, ff, closure);
606 for (s = -1; s <= 1; s += 2) {
607 if (rf > 0 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
608 ((flags & F_KRIEGSPIEL_CAPTURE) ||
609 WhitePiece(board[rf - 1][ff + s]))) {
610 callback(board, flags,
611 rf <= promoRank ? BlackPromotion : NormalMove,
612 rf, ff, rf - 1, ff + s, closure);
614 if (rf < BOARD_HEIGHT>>1) {
615 if (ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
616 (epfile == ff + s || epfile == EP_UNKNOWN) && rf > 2 &&
617 board[rf][ff + s] == WhitePawn &&
618 board[rf-1][ff + s] == EmptySquare) {
619 callback(board, flags, BlackCapturesEnPassant,
620 rf, ff, rf-1, ff + s, closure);
630 for (i = -1; i <= 1; i += 2)
631 for (j = -1; j <= 1; j += 2)
632 for (s = 1; s <= 2; s++) {
635 if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
636 && ( gameInfo.variant != VariantXiangqi || board[rf+i*(s-1)][ff+j*(2-s)] == EmptySquare)
637 && !SameColor(board[rf][ff], board[rt][ft]))
638 callback(board, flags, NormalMove,
639 rf, ff, rt, ft, closure);
643 case SHOGI WhiteKnight:
644 for (s = -1; s <= 1; s += 2) {
645 if (rf < BOARD_HEIGHT-2 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
646 !SameColor(board[rf][ff], board[rf + 2][ff + s])) {
647 callback(board, flags, NormalMove,
648 rf, ff, rf + 2, ff + s, closure);
653 case SHOGI BlackKnight:
654 for (s = -1; s <= 1; s += 2) {
655 if (rf > 1 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
656 !SameColor(board[rf][ff], board[rf - 2][ff + s])) {
657 callback(board, flags, NormalMove,
658 rf, ff, rf - 2, ff + s, closure);
665 for (d = 0; d <= 1; d++)
666 for (s = -1; s <= 1; s += 2) {
669 rt = rf + (i * s) * d;
670 ft = ff + (i * s) * (1 - d);
671 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
672 if (m == 0 && board[rt][ft] == EmptySquare)
673 callback(board, flags, NormalMove,
674 rf, ff, rt, ft, closure);
675 if (m == 1 && board[rt][ft] != EmptySquare &&
676 !SameColor(board[rf][ff], board[rt][ft]) )
677 callback(board, flags, NormalMove,
678 rf, ff, rt, ft, closure);
679 if (board[rt][ft] != EmptySquare && m++) break;
684 /* Gold General (and all its promoted versions) . First do the */
685 /* diagonal forward steps, then proceed as normal Wazir */
686 case SHOGI (PROMOTED WhitePawn):
687 if(gameInfo.variant == VariantShogi) goto WhiteGold;
688 case SHOGI (PROMOTED BlackPawn):
689 if(gameInfo.variant == VariantShogi) goto BlackGold;
690 SlideVertical(board, flags, rf, ff, callback, closure);
693 case SHOGI (PROMOTED WhiteKnight):
694 if(gameInfo.variant == VariantShogi) goto WhiteGold;
695 case SHOGI BlackDrunk:
696 case SHOGI BlackAlfil:
697 Ferz(board, flags, rf, ff, callback, closure);
698 StepSideways(board, flags, rf, ff, callback, closure);
699 StepBackward(board, flags, rf, ff, callback, closure);
702 case SHOGI (PROMOTED BlackKnight):
703 if(gameInfo.variant == VariantShogi) goto BlackGold;
704 case SHOGI WhiteDrunk:
705 case SHOGI WhiteAlfil:
706 Ferz(board, flags, rf, ff, callback, closure);
707 StepSideways(board, flags, rf, ff, callback, closure);
708 StepForward(board, flags, rf, ff, callback, closure);
712 case SHOGI WhiteStag:
713 case SHOGI BlackStag:
714 if(gameInfo.variant == VariantShogi) goto BlackGold;
715 SlideVertical(board, flags, rf, ff, callback, closure);
716 Ferz(board, flags, rf, ff, callback, closure);
717 StepSideways(board, flags, rf, ff, callback, closure);
720 case SHOGI (PROMOTED WhiteQueen):
721 case SHOGI WhiteTokin:
722 case SHOGI WhiteWazir:
724 StepDiagForward(board, flags, rf, ff, callback, closure);
725 Wazir(board, flags, rf, ff, callback, closure);
728 case SHOGI (PROMOTED BlackQueen):
729 case SHOGI BlackTokin:
730 case SHOGI BlackWazir:
732 StepDiagBackward(board, flags, rf, ff, callback, closure);
733 Wazir(board, flags, rf, ff, callback, closure);
738 Wazir(board, flags, rf, ff, callback, closure);
741 case SHOGI WhiteMarshall:
742 case SHOGI BlackMarshall:
743 Ferz(board, flags, rf, ff, callback, closure);
744 for (d = 0; d <= 1; d++)
745 for (s = -2; s <= 2; s += 4) {
747 ft = ff + s * (1 - d);
748 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) continue;
749 if (!SameColor(board[rf][ff], board[rt][ft]) )
750 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
754 case SHOGI WhiteAngel:
755 case SHOGI BlackAngel:
756 Wazir(board, flags, rf, ff, callback, closure);
760 /* [HGM] support Shatranj pieces */
761 for (rs = -1; rs <= 1; rs += 2)
762 for (fs = -1; fs <= 1; fs += 2) {
765 if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
766 && ( gameInfo.variant != VariantXiangqi ||
767 board[rf+rs][ff+fs] == EmptySquare && (2*rf < BOARD_HEIGHT) == (2*rt < BOARD_HEIGHT) )
769 && !SameColor(board[rf][ff], board[rt][ft]))
770 callback(board, flags, NormalMove,
771 rf, ff, rt, ft, closure);
772 if(gameInfo.variant == VariantShatranj || gameInfo.variant == VariantCourier ||
773 gameInfo.variant == VariantChu || gameInfo.variant == VariantXiangqi) continue; // classical Alfil
774 rt = rf + rs; // in unknown variant we assume Modern Elephant, which can also do one step
776 if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
777 && !SameColor(board[rf][ff], board[rt][ft]))
778 callback(board, flags, NormalMove,
779 rf, ff, rt, ft, closure);
781 if(gameInfo.variant == VariantSpartan)
782 for(fs = -1; fs <= 1; fs += 2) {
784 if (!(ft < BOARD_LEFT || ft >= BOARD_RGHT) && board[rf][ft] == EmptySquare)
785 callback(board, flags, NormalMove, rf, ff, rf, ft, closure);
789 /* Make Dragon-Horse also do Dababba moves outside Shogi, for better disambiguation in variant Fairy */
792 if(gameInfo.variant == VariantChuChess) goto DragonHorse;
793 for (d = 0; d <= 1; d++) // Dababba moves that Rook cannot do
794 for (s = -2; s <= 2; s += 4) {
796 ft = ff + s * (1 - d);
797 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) continue;
798 if (SameColor(board[rf][ff], board[rt][ft])) continue;
799 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
802 /* Shogi Dragon Horse has to continue with Wazir after Bishop */
803 case SHOGI WhiteCardinal:
804 case SHOGI BlackCardinal:
805 case SHOGI WhitePCardinal:
806 case SHOGI BlackPCardinal:
808 Bishop(board, flags, rf, ff, callback, closure);
809 Wazir(board, flags, rf, ff, callback, closure);
812 /* Capablanca Archbishop continues as Knight */
815 Knight(board, flags, rf, ff, callback, closure);
817 /* Shogi Bishops are ordinary Bishops */
818 case SHOGI WhiteBishop:
819 case SHOGI BlackBishop:
820 case SHOGI WhitePBishop:
821 case SHOGI BlackPBishop:
824 Bishop(board, flags, rf, ff, callback, closure);
827 /* Shogi Lance is unlike anything, and asymmetric at that */
828 case SHOGI WhiteQueen:
829 if(gameInfo.variant == VariantChu) goto doQueen;
833 if (rt >= BOARD_HEIGHT) break;
834 if (SameColor(board[rf][ff], board[rt][ft])) break;
835 callback(board, flags, NormalMove,
836 rf, ff, rt, ft, closure);
837 if (board[rt][ft] != EmptySquare) break;
841 case SHOGI BlackQueen:
842 if(gameInfo.variant == VariantChu) goto doQueen;
847 if (SameColor(board[rf][ff], board[rt][ft])) break;
848 callback(board, flags, NormalMove,
849 rf, ff, rt, ft, closure);
850 if (board[rt][ft] != EmptySquare) break;
854 /* Make Dragon-King Dababba & Rook-like outside Shogi, for better disambiguation in variant Fairy */
857 if(gameInfo.variant == VariantChuChess) goto DragonKing;
858 for (d = 0; d <= 1; d++) // Dababba moves that Rook cannot do
859 for (s = -2; s <= 2; s += 4) {
861 ft = ff + s * (1 - d);
862 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) continue;
863 if (board[rf+rt>>1][ff+ft>>1] == EmptySquare && gameInfo.variant != VariantSpartan) continue;
864 if (SameColor(board[rf][ff], board[rt][ft])) continue;
865 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
867 if(gameInfo.variant == VariantSpartan) // in Spartan Chess restrict range to modern Dababba
868 Wazir(board, flags, rf, ff, callback, closure);
870 Rook(board, flags, rf, ff, callback, closure);
873 /* Shogi Dragon King has to continue as Ferz after Rook moves */
874 case SHOGI WhiteDragon:
875 case SHOGI BlackDragon:
876 case SHOGI WhitePDragon:
877 case SHOGI BlackPDragon:
879 Rook(board, flags, rf, ff, callback, closure);
880 Ferz(board, flags, rf, ff, callback, closure);
884 /* Capablanca Chancellor sets flag to continue as Knight */
887 Rook(board, flags, rf, ff, callback, closure);
888 if(gameInfo.variant == VariantSpartan) // in Spartan Chess Chancellor is used for Dragon King.
889 Ferz(board, flags, rf, ff, callback, closure);
891 Knight(board, flags, rf, ff, callback, closure);
894 /* Shogi Rooks are ordinary Rooks */
895 case SHOGI WhiteRook:
896 case SHOGI BlackRook:
897 case SHOGI WhitePRook:
898 case SHOGI BlackPRook:
901 Rook(board, flags, rf, ff, callback, closure);
906 case SHOGI WhiteMother:
907 case SHOGI BlackMother:
909 Rook(board, flags, rf, ff, callback, closure);
910 Bishop(board, flags, rf, ff, callback, closure);
913 case SHOGI WhitePawn:
914 StepForward(board, flags, rf, ff, callback, closure);
917 case SHOGI BlackPawn:
918 StepBackward(board, flags, rf, ff, callback, closure);
922 if(gameInfo.variant != VariantMakruk && gameInfo.variant != VariantASEAN) goto commoner;
923 case SHOGI WhiteFerz:
924 Ferz(board, flags, rf, ff, callback, closure);
925 StepForward(board, flags, rf, ff, callback, closure);
929 if(gameInfo.variant != VariantMakruk && gameInfo.variant != VariantASEAN) goto commoner;
930 case SHOGI BlackFerz:
931 StepBackward(board, flags, rf, ff, callback, closure);
935 /* [HGM] support Shatranj pieces */
936 Ferz(board, flags, rf, ff, callback, closure);
941 Knight(board, flags, rf, ff, callback, closure); // [HGM] superchess: use for Centaur
944 case SHOGI WhiteMonarch:
945 case SHOGI BlackMonarch:
946 case SHOGI WhiteKing:
947 case SHOGI BlackKing:
950 Ferz(board, flags, rf, ff, callback, closure);
951 Wazir(board, flags, rf, ff, callback, closure);
954 case WhiteNightrider:
955 case BlackNightrider:
956 for (i = -1; i <= 1; i += 2)
957 for (j = -1; j <= 1; j += 2)
958 for (s = 1; s <= 2; s++) { int k;
962 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
963 if (SameColor(board[rf][ff], board[rt][ft])) break;
964 callback(board, flags, NormalMove,
965 rf, ff, rt, ft, closure);
966 if (board[rt][ft] != EmptySquare) break;
972 Bishop(board, flags, rf, ff, callback, closure);
973 Rook(board, flags, rf, ff, callback, closure);
974 Knight(board, flags, rf, ff, callback, closure);
977 // Use Lance as Berolina / Spartan Pawn.
979 if(gameInfo.variant == VariantSuper) goto Amazon;
980 if (rf < BOARD_HEIGHT-1 && BlackPiece(board[rf + 1][ff]))
981 callback(board, flags,
982 rf >= BOARD_HEIGHT-1-promoRank ? WhitePromotion : NormalMove,
983 rf, ff, rf + 1, ff, closure);
984 for (s = -1; s <= 1; s += 2) {
985 if (rf < BOARD_HEIGHT-1 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT && board[rf + 1][ff + s] == EmptySquare)
986 callback(board, flags,
987 rf >= BOARD_HEIGHT-1-promoRank ? WhitePromotion : NormalMove,
988 rf, ff, rf + 1, ff + s, closure);
989 if (rf == 1 && ff + 2*s >= BOARD_LEFT && ff + 2*s < BOARD_RGHT && board[3][ff + 2*s] == EmptySquare )
990 callback(board, flags, NormalMove, rf, ff, 3, ff + 2*s, closure);
995 if(gameInfo.variant == VariantSuper) goto Amazon;
996 if (rf > 0 && WhitePiece(board[rf - 1][ff]))
997 callback(board, flags,
998 rf <= promoRank ? BlackPromotion : NormalMove,
999 rf, ff, rf - 1, ff, closure);
1000 for (s = -1; s <= 1; s += 2) {
1001 if (rf > 0 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT && board[rf - 1][ff + s] == EmptySquare)
1002 callback(board, flags,
1003 rf <= promoRank ? BlackPromotion : NormalMove,
1004 rf, ff, rf - 1, ff + s, closure);
1005 if (rf == BOARD_HEIGHT-2 && ff + 2*s >= BOARD_LEFT && ff + 2*s < BOARD_RGHT && board[rf-2][ff + 2*s] == EmptySquare )
1006 callback(board, flags, NormalMove, rf, ff, rf-2, ff + 2*s, closure);
1010 case SHOGI WhiteNothing:
1011 case SHOGI BlackNothing:
1012 case SHOGI WhiteLion:
1013 case SHOGI BlackLion:
1016 for(rt = rf - 2; rt <= rf + 2; rt++) for(ft = ff - 2; ft <= ff + 2; ft++) {
1017 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) continue;
1018 if (!(ff == ft && rf == rt) && SameColor(board[rf][ff], board[rt][ft])) continue;
1019 callback(board, flags, (rt-rf)*(rt-rf) + (ff-ft)*(ff-ft) < 3 && board[rt][ft] != EmptySquare ? FirstLeg : NormalMove,
1020 rf, ff, rt, ft, closure);
1024 case SHOGI WhiteFalcon:
1025 case SHOGI BlackFalcon:
1026 case SHOGI WhitePDagger:
1027 case SHOGI BlackPDagger:
1028 SlideSideways(board, flags, rf, ff, callback, closure);
1029 StepVertical(board, flags, rf, ff, callback, closure);
1032 case SHOGI WhiteCobra:
1033 case SHOGI BlackCobra:
1034 StepVertical(board, flags, rf, ff, callback, closure);
1037 case SHOGI (PROMOTED WhiteFerz):
1038 if(gameInfo.variant == VariantShogi) goto WhiteGold;
1039 case SHOGI (PROMOTED BlackFerz):
1040 if(gameInfo.variant == VariantShogi) goto BlackGold;
1041 case SHOGI WhitePSword:
1042 case SHOGI BlackPSword:
1043 SlideVertical(board, flags, rf, ff, callback, closure);
1044 StepSideways(board, flags, rf, ff, callback, closure);
1047 case SHOGI WhiteUnicorn:
1048 case SHOGI BlackUnicorn:
1049 Ferz(board, flags, rf, ff, callback, closure);
1050 StepVertical(board, flags, rf, ff, callback, closure);
1053 case SHOGI WhiteMan:
1054 StepDiagForward(board, flags, rf, ff, callback, closure);
1055 StepVertical(board, flags, rf, ff, callback, closure);
1058 case SHOGI BlackMan:
1059 StepDiagBackward(board, flags, rf, ff, callback, closure);
1060 StepVertical(board, flags, rf, ff, callback, closure);
1063 case SHOGI WhiteHCrown:
1064 case SHOGI BlackHCrown:
1065 Bishop(board, flags, rf, ff, callback, closure);
1066 SlideSideways(board, flags, rf, ff, callback, closure);
1069 case SHOGI WhiteCrown:
1070 case SHOGI BlackCrown:
1071 Bishop(board, flags, rf, ff, callback, closure);
1072 SlideVertical(board, flags, rf, ff, callback, closure);
1075 case SHOGI WhiteHorned:
1076 Sting(board, flags, rf, ff, 1, 0, callback, closure);
1077 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1078 if(killX >= 0) break;
1079 Bishop(board, flags, rf, ff, callback, closure);
1080 SlideSideways(board, flags, rf, ff, callback, closure);
1081 SlideBackward(board, flags, rf, ff, callback, closure);
1084 case SHOGI BlackHorned:
1085 Sting(board, flags, rf, ff, -1, 0, callback, closure);
1086 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1087 if(killX >= 0) break;
1088 Bishop(board, flags, rf, ff, callback, closure);
1089 SlideSideways(board, flags, rf, ff, callback, closure);
1090 SlideForward(board, flags, rf, ff, callback, closure);
1093 case SHOGI WhiteEagle:
1094 Sting(board, flags, rf, ff, 1, 1, callback, closure);
1095 Sting(board, flags, rf, ff, 1, -1, callback, closure);
1096 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1097 if(killX >= 0) break;
1098 Rook(board, flags, rf, ff, callback, closure);
1099 SlideDiagBackward(board, flags, rf, ff, callback, closure);
1102 case SHOGI BlackEagle:
1103 Sting(board, flags, rf, ff, -1, 1, callback, closure);
1104 Sting(board, flags, rf, ff, -1, -1, callback, closure);
1105 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1106 if(killX >= 0) break;
1107 Rook(board, flags, rf, ff, callback, closure);
1108 SlideDiagForward(board, flags, rf, ff, callback, closure);
1111 case SHOGI WhiteDolphin:
1112 case SHOGI BlackHorse:
1113 SlideDiagBackward(board, flags, rf, ff, callback, closure);
1114 SlideVertical(board, flags, rf, ff, callback, closure);
1117 case SHOGI BlackDolphin:
1118 case SHOGI WhiteHorse:
1119 SlideDiagForward(board, flags, rf, ff, callback, closure);
1120 SlideVertical(board, flags, rf, ff, callback, closure);
1123 case SHOGI WhiteLance:
1124 SlideForward(board, flags, rf, ff, callback, closure);
1127 case SHOGI BlackLance:
1128 SlideBackward(board, flags, rf, ff, callback, closure);
1131 case WhiteFalcon: // [HGM] wild: for wildcards, self-capture symbolizes move to anywhere
1135 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1148 int rFilter, fFilter; // [HGM] speed: sorry, but I get a bit tired of this closure madness
1149 Board xqCheckers, nullBoard;
1151 extern void GenLegalCallback P((Board board, int flags, ChessMove kind,
1152 int rf, int ff, int rt, int ft,
1156 GenLegalCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1158 register GenLegalClosure *cl = (GenLegalClosure *) closure;
1160 if(rFilter >= 0 && rFilter != rt || fFilter >= 0 && fFilter != ft) return; // [HGM] speed: ignore moves with wrong to-square
1162 if (board[EP_STATUS] == EP_IRON_LION && (board[rt][ft] == WhiteLion || board[rt][ft] == BlackLion)) return; //[HGM] lion
1164 if (!(flags & F_IGNORE_CHECK) ) {
1165 int check, promo = (gameInfo.variant == VariantSpartan && kind == BlackPromotion);
1168 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++)
1169 kings += (board[r][f] == BlackKing);
1173 board[rf][ff] = BlackKing; // [HGM] spartan: promote to King before check-test
1175 check = CheckTest(board, flags, rf, ff, rt, ft,
1176 kind == WhiteCapturesEnPassant ||
1177 kind == BlackCapturesEnPassant);
1178 if(promo) board[rf][ff] = BlackLance;
1181 if (flags & F_ATOMIC_CAPTURE) {
1182 if (board[rt][ft] != EmptySquare ||
1183 kind == WhiteCapturesEnPassant || kind == BlackCapturesEnPassant) {
1185 ChessSquare king = (flags & F_WHITE_ON_MOVE) ? WhiteKing : BlackKing;
1186 if (board[rf][ff] == king) return;
1187 for (r = rt-1; r <= rt+1; r++) {
1188 for (f = ft-1; f <= ft+1; f++) {
1189 if (r >= 0 && r < BOARD_HEIGHT && f >= BOARD_LEFT && f < BOARD_RGHT &&
1190 board[r][f] == king) return;
1195 cl->cb(board, flags, kind, rf, ff, rt, ft, cl->cl);
1202 int captures; // [HGM] losers
1203 } LegalityTestClosure;
1206 /* Like GenPseudoLegal, but (1) include castling moves, (2) unless
1207 F_IGNORE_CHECK is set in the flags, omit moves that would leave the
1208 king in check, and (3) if F_ATOMIC_CAPTURE is set in the flags, omit
1209 moves that would destroy your own king. The CASTLE_OK flags are
1210 true if castling is not yet ruled out by a move of the king or
1211 rook. Return TRUE if the player on move is currently in check and
1212 F_IGNORE_CHECK is not set. [HGM] add castlingRights parameter */
1214 GenLegal (Board board, int flags, MoveCallback callback, VOIDSTAR closure, ChessSquare filter)
1217 int ff, ft, k, left, right, swap;
1218 int ignoreCheck = (flags & F_IGNORE_CHECK) != 0;
1219 ChessSquare wKing = WhiteKing, bKing = BlackKing, *castlingRights = board[CASTLING];
1220 int inCheck = !ignoreCheck && CheckTest(board, flags, -1, -1, -1, -1, FALSE); // kludge alert: this would mark pre-existing checkers if status==1
1224 xqCheckers[EP_STATUS] *= 2; // quasi: if previous CheckTest has been marking, we now set flag for suspending same checkers
1225 if(filter == EmptySquare) rFilter = fFilter = -1; // [HGM] speed: do not filter on square if we do not filter on piece
1226 GenPseudoLegal(board, flags, GenLegalCallback, (VOIDSTAR) &cl, filter);
1228 if (inCheck) return TRUE;
1230 /* Generate castling moves */
1231 if(gameInfo.variant == VariantKnightmate) { /* [HGM] Knightmate */
1232 wKing = WhiteUnicorn; bKing = BlackUnicorn;
1235 for (ff = BOARD_WIDTH>>1; ff >= (BOARD_WIDTH-1)>>1; ff-- /*ics wild 1*/) {
1236 if ((flags & F_WHITE_ON_MOVE) &&
1237 (flags & F_WHITE_KCASTLE_OK) &&
1238 board[0][ff] == wKing &&
1239 board[0][ff + 1] == EmptySquare &&
1240 board[0][ff + 2] == EmptySquare &&
1241 board[0][BOARD_RGHT-3] == EmptySquare &&
1242 board[0][BOARD_RGHT-2] == EmptySquare &&
1243 board[0][BOARD_RGHT-1] == WhiteRook &&
1244 castlingRights[0] != NoRights && /* [HGM] check rights */
1245 ( castlingRights[2] == ff || castlingRights[6] == ff ) &&
1247 (!CheckTest(board, flags, 0, ff, 0, ff + 1, FALSE) &&
1248 !CheckTest(board, flags, 0, ff, 0, BOARD_RGHT-3, FALSE) &&
1249 (gameInfo.variant != VariantJanus || !CheckTest(board, flags, 0, ff, 0, BOARD_RGHT-2, FALSE)) &&
1250 !CheckTest(board, flags, 0, ff, 0, ff + 2, FALSE)))) {
1252 callback(board, flags,
1253 ff==BOARD_WIDTH>>1 ? WhiteKingSideCastle : WhiteKingSideCastleWild,
1254 0, ff, 0, ff + ((gameInfo.boardWidth+2)>>2) + (gameInfo.variant == VariantJanus), closure);
1256 if ((flags & F_WHITE_ON_MOVE) &&
1257 (flags & F_WHITE_QCASTLE_OK) &&
1258 board[0][ff] == wKing &&
1259 board[0][ff - 1] == EmptySquare &&
1260 board[0][ff - 2] == EmptySquare &&
1261 board[0][BOARD_LEFT+2] == EmptySquare &&
1262 board[0][BOARD_LEFT+1] == EmptySquare &&
1263 board[0][BOARD_LEFT+0] == WhiteRook &&
1264 castlingRights[1] != NoRights && /* [HGM] check rights */
1265 ( castlingRights[2] == ff || castlingRights[6] == ff ) &&
1267 (!CheckTest(board, flags, 0, ff, 0, ff - 1, FALSE) &&
1268 !CheckTest(board, flags, 0, ff, 0, BOARD_LEFT+3, FALSE) &&
1269 !CheckTest(board, flags, 0, ff, 0, ff - 2, FALSE)))) {
1271 callback(board, flags,
1272 ff==BOARD_WIDTH>>1 ? WhiteQueenSideCastle : WhiteQueenSideCastleWild,
1273 0, ff, 0, ff - ((gameInfo.boardWidth+2)>>2), closure);
1275 if (!(flags & F_WHITE_ON_MOVE) &&
1276 (flags & F_BLACK_KCASTLE_OK) &&
1277 board[BOARD_HEIGHT-1][ff] == bKing &&
1278 board[BOARD_HEIGHT-1][ff + 1] == EmptySquare &&
1279 board[BOARD_HEIGHT-1][ff + 2] == EmptySquare &&
1280 board[BOARD_HEIGHT-1][BOARD_RGHT-3] == EmptySquare &&
1281 board[BOARD_HEIGHT-1][BOARD_RGHT-2] == EmptySquare &&
1282 board[BOARD_HEIGHT-1][BOARD_RGHT-1] == BlackRook &&
1283 castlingRights[3] != NoRights && /* [HGM] check rights */
1284 ( castlingRights[5] == ff || castlingRights[7] == ff ) &&
1286 (!CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff + 1, FALSE) &&
1287 !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, BOARD_RGHT-3, FALSE) &&
1288 (gameInfo.variant != VariantJanus || !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, BOARD_RGHT-2, FALSE)) &&
1289 !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff + 2, FALSE)))) {
1291 callback(board, flags,
1292 ff==BOARD_WIDTH>>1 ? BlackKingSideCastle : BlackKingSideCastleWild,
1293 BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff + ((gameInfo.boardWidth+2)>>2) + (gameInfo.variant == VariantJanus), closure);
1295 if (!(flags & F_WHITE_ON_MOVE) &&
1296 (flags & F_BLACK_QCASTLE_OK) &&
1297 board[BOARD_HEIGHT-1][ff] == bKing &&
1298 board[BOARD_HEIGHT-1][ff - 1] == EmptySquare &&
1299 board[BOARD_HEIGHT-1][ff - 2] == EmptySquare &&
1300 board[BOARD_HEIGHT-1][BOARD_LEFT+2] == EmptySquare &&
1301 board[BOARD_HEIGHT-1][BOARD_LEFT+1] == EmptySquare &&
1302 board[BOARD_HEIGHT-1][BOARD_LEFT+0] == BlackRook &&
1303 castlingRights[4] != NoRights && /* [HGM] check rights */
1304 ( castlingRights[5] == ff || castlingRights[7] == ff ) &&
1306 (!CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff - 1, FALSE) &&
1307 !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, BOARD_LEFT+3, FALSE) &&
1308 !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff - 2, FALSE)))) {
1310 callback(board, flags,
1311 ff==BOARD_WIDTH>>1 ? BlackQueenSideCastle : BlackQueenSideCastleWild,
1312 BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff - ((gameInfo.boardWidth+2)>>2), closure);
1316 if((swap = gameInfo.variant == VariantSChess) || flags & F_FRC_TYPE_CASTLING) {
1318 /* generate all potential FRC castling moves (KxR), ignoring flags */
1319 /* [HGM] test if the Rooks we find have castling rights */
1320 /* In S-Chess we generate RxK for allowed castlings, for gating at Rook square */
1323 if ((flags & F_WHITE_ON_MOVE) != 0) {
1324 ff = castlingRights[2]; /* King file if we have any rights */
1325 if(ff != NoRights && board[0][ff] == WhiteKing) {
1326 if (appData.debugMode) {
1327 fprintf(debugFP, "FRC castling, %d %d %d %d %d %d\n",
1328 castlingRights[0],castlingRights[1],ff,castlingRights[3],castlingRights[4],castlingRights[5]);
1330 ft = castlingRights[0]; /* Rook file if we have H-side rights */
1332 right = BOARD_RGHT-2;
1333 if(ff == BOARD_RGHT-2) left = right = ff-1; /* special case */
1334 for(k=left; k<=right && ft != NoRights; k++) /* first test if blocked */
1335 if(k != ft && board[0][k] != EmptySquare) ft = NoRights;
1336 for(k=left; k<right && ft != NoRights; k++) /* then if not checked */
1337 if(!ignoreCheck && CheckTest(board, flags, 0, ff, 0, k, FALSE)) ft = NoRights;
1338 if(ft != NoRights && board[0][ft] == WhiteRook) {
1339 if(flags & F_FRC_TYPE_CASTLING) callback(board, flags, WhiteHSideCastleFR, 0, ff, 0, ft, closure);
1340 if(swap) callback(board, flags, WhiteHSideCastleFR, 0, ft, 0, ff, closure);
1343 ft = castlingRights[1]; /* Rook file if we have A-side rights */
1344 left = BOARD_LEFT+2;
1346 if(ff <= BOARD_LEFT+2) { left = ff+1; right = BOARD_LEFT+3; }
1347 for(k=left; k<=right && ft != NoRights; k++) /* first test if blocked */
1348 if(k != ft && board[0][k] != EmptySquare) ft = NoRights;
1349 if(ft == 0 && ff != 1 && board[0][1] != EmptySquare) ft = NoRights; /* Rook can be blocked on b1 */
1350 if(ff > BOARD_LEFT+2)
1351 for(k=left+1; k<=right && ft != NoRights; k++) /* then if not checked */
1352 if(!ignoreCheck && CheckTest(board, flags, 0, ff, 0, k, FALSE)) ft = NoRights;
1353 if(ft != NoRights && board[0][ft] == WhiteRook) {
1354 if(flags & F_FRC_TYPE_CASTLING) callback(board, flags, WhiteASideCastleFR, 0, ff, 0, ft, closure);
1355 if(swap) callback(board, flags, WhiteASideCastleFR, 0, ft, 0, ff, closure);
1359 ff = castlingRights[5]; /* King file if we have any rights */
1360 if(ff != NoRights && board[BOARD_HEIGHT-1][ff] == BlackKing) {
1361 ft = castlingRights[3]; /* Rook file if we have H-side rights */
1363 right = BOARD_RGHT-2;
1364 if(ff == BOARD_RGHT-2) left = right = ff-1; /* special case */
1365 for(k=left; k<=right && ft != NoRights; k++) /* first test if blocked */
1366 if(k != ft && board[BOARD_HEIGHT-1][k] != EmptySquare) ft = NoRights;
1367 for(k=left; k<right && ft != NoRights; k++) /* then if not checked */
1368 if(!ignoreCheck && CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, k, FALSE)) ft = NoRights;
1369 if(ft != NoRights && board[BOARD_HEIGHT-1][ft] == BlackRook) {
1370 if(flags & F_FRC_TYPE_CASTLING) callback(board, flags, BlackHSideCastleFR, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ft, closure);
1371 if(swap) callback(board, flags, BlackHSideCastleFR, BOARD_HEIGHT-1, ft, BOARD_HEIGHT-1, ff, closure);
1374 ft = castlingRights[4]; /* Rook file if we have A-side rights */
1375 left = BOARD_LEFT+2;
1377 if(ff <= BOARD_LEFT+2) { left = ff+1; right = BOARD_LEFT+3; }
1378 for(k=left; k<=right && ft != NoRights; k++) /* first test if blocked */
1379 if(k != ft && board[BOARD_HEIGHT-1][k] != EmptySquare) ft = NoRights;
1380 if(ft == 0 && ff != 1 && board[BOARD_HEIGHT-1][1] != EmptySquare) ft = NoRights; /* Rook can be blocked on b8 */
1381 if(ff > BOARD_LEFT+2)
1382 for(k=left+1; k<=right && ft != NoRights; k++) /* then if not checked */
1383 if(!ignoreCheck && CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, k, FALSE)) ft = NoRights;
1384 if(ft != NoRights && board[BOARD_HEIGHT-1][ft] == BlackRook) {
1385 if(flags & F_FRC_TYPE_CASTLING) callback(board, flags, BlackASideCastleFR, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ft, closure);
1386 if(swap) callback(board, flags, BlackASideCastleFR, BOARD_HEIGHT-1, ft, BOARD_HEIGHT-1, ff, closure);
1403 extern void CheckTestCallback P((Board board, int flags, ChessMove kind,
1404 int rf, int ff, int rt, int ft,
1409 CheckTestCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1411 register CheckTestClosure *cl = (CheckTestClosure *) closure;
1413 if (rt == cl->rking && ft == cl->fking) {
1414 if(xqCheckers[EP_STATUS] >= 2 && xqCheckers[rf][ff]) return; // checker is piece with suspended checking power
1416 xqCheckers[rf][ff] = xqCheckers[EP_STATUS] & 1; // remember who is checking (if status == 1)
1418 if( board[EP_STATUS] == EP_ROYAL_LION && (board[rt][ft] == WhiteLion || board[rt][ft] == BlackLion)
1419 && (gameInfo.variant != VariantLion || board[rf][ff] != WhiteKing && board[rf][ff] != BlackKing) )
1420 cl->check++; // [HGM] lion: forbidden counterstrike against Lion equated to putting yourself in check
1424 /* If the player on move were to move from (rf, ff) to (rt, ft), would
1425 he leave himself in check? Or if rf == -1, is the player on move
1426 in check now? enPassant must be TRUE if the indicated move is an
1427 e.p. capture. The possibility of castling out of a check along the
1428 back rank is not accounted for (i.e., we still return nonzero), as
1429 this is illegal anyway. Return value is the number of times the
1430 king is in check. */
1432 CheckTest (Board board, int flags, int rf, int ff, int rt, int ft, int enPassant)
1434 CheckTestClosure cl;
1435 ChessSquare king = flags & F_WHITE_ON_MOVE ? WhiteKing : BlackKing;
1436 ChessSquare captured = EmptySquare, ep=0, trampled=0;
1437 /* Suppress warnings on uninitialized variables */
1439 if(gameInfo.variant == VariantXiangqi)
1440 king = flags & F_WHITE_ON_MOVE ? WhiteWazir : BlackWazir;
1441 if(gameInfo.variant == VariantKnightmate)
1442 king = flags & F_WHITE_ON_MOVE ? WhiteUnicorn : BlackUnicorn;
1443 if(gameInfo.variant == VariantChu) { // strictly speaking this is not needed, as Chu officially has no check
1444 int r, f, k = king, royals=0, prince = flags & F_WHITE_ON_MOVE ? WhiteMonarch : BlackMonarch;
1445 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++) {
1446 if(board[r][f] == k || board[r][f] == prince) {
1447 if(++royals > 1) return FALSE; // no check if we have two royals (ignores double captureby Lion!)
1448 king = board[r][f]; // remember hich one we had
1455 captured = board[rf][ft];
1456 board[rf][ft] = EmptySquare;
1458 captured = board[rt][ft];
1459 if(killX >= 0) { trampled = board[killY][killX]; board[killY][killX] = EmptySquare; }
1461 if(rf == DROP_RANK) board[rt][ft] = ff; else { // [HGM] drop
1462 board[rt][ft] = board[rf][ff];
1463 board[rf][ff] = EmptySquare;
1465 ep = board[EP_STATUS];
1466 if( captured == WhiteLion || captured == BlackLion ) { // [HGM] lion: Chu Lion-capture rules
1467 ChessSquare victim = killX < 0 ? EmptySquare : trampled;
1468 if( (board[rt][ft] == WhiteLion || board[rt][ft] == BlackLion) && // capturer is Lion
1469 (ff - ft > 1 || ft - ff > 1 || rf - rt > 1 || rt - rf > 1) && // captures from a distance
1470 (victim == EmptySquare || victim == WhitePawn || victim == BlackPawn) ) // no or worthless 'bridge'
1471 board[EP_STATUS] = EP_ROYAL_LION; // on distant Lion x Lion victim must not be pseudo-legally protected
1475 /* For compatibility with ICS wild 9, we scan the board in the
1476 order a1, a2, a3, ... b1, b2, ..., h8 to find the first king,
1477 and we test only whether that one is in check. */
1478 for (cl.fking = BOARD_LEFT+0; cl.fking < BOARD_RGHT; cl.fking++)
1479 for (cl.rking = 0; cl.rking < BOARD_HEIGHT; cl.rking++) {
1480 if (board[cl.rking][cl.fking] == king) {
1482 if(gameInfo.variant == VariantXiangqi) {
1483 /* [HGM] In Xiangqi opposing Kings means check as well */
1485 dir = (king >= BlackPawn) ? -1 : 1;
1486 for( i=cl.rking+dir; i>=0 && i<BOARD_HEIGHT &&
1487 board[i][cl.fking] == EmptySquare; i+=dir );
1488 if(i>=0 && i<BOARD_HEIGHT &&
1489 board[i][cl.fking] == (dir>0 ? BlackWazir : WhiteWazir) )
1492 GenPseudoLegal(board, flags ^ F_WHITE_ON_MOVE, CheckTestCallback, (VOIDSTAR) &cl, EmptySquare);
1493 if(gameInfo.variant != VariantSpartan || cl.check == 0) // in Spartan Chess go on to test if other King is checked too
1494 goto undo_move; /* 2-level break */
1501 if(rf != DROP_RANK) // [HGM] drop
1502 board[rf][ff] = board[rt][ft];
1504 board[rf][ft] = captured;
1505 board[rt][ft] = EmptySquare;
1507 if(killX >= 0) board[killY][killX] = trampled;
1508 board[rt][ft] = captured;
1510 board[EP_STATUS] = ep;
1513 return cl.fking < BOARD_RGHT ? cl.check : 1000; // [HGM] atomic: return 1000 if we have no king
1517 HasLion (Board board, int flags)
1519 int lion = F_WHITE_ON_MOVE & flags ? WhiteLion : BlackLion;
1521 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++)
1522 if(board[r][f] == lion) return 1;
1527 LegalDrop (Board board, int flags, ChessSquare piece, int rt, int ft)
1528 { // [HGM] put drop legality testing in separate routine for clarity
1530 if(appData.debugMode) fprintf(debugFP, "LegalDrop: %d @ %d,%d)\n", piece, ft, rt);
1531 if(board[rt][ft] != EmptySquare) return ImpossibleMove; // must drop to empty square
1532 n = PieceToNumber(piece);
1533 if((gameInfo.holdingsWidth == 0 || (flags & F_WHITE_ON_MOVE ? board[n][BOARD_WIDTH-1] : board[BOARD_HEIGHT-1-n][0]) != piece)
1534 && gameInfo.variant != VariantBughouse) // in bughouse we don't check for availability, because ICS doesn't always tell us
1535 return ImpossibleMove; // piece not available
1536 if(gameInfo.variant == VariantShogi) { // in Shogi lots of drops are forbidden!
1537 if((piece == WhitePawn || piece == WhiteQueen) && rt == BOARD_HEIGHT-1 ||
1538 (piece == BlackPawn || piece == BlackQueen) && rt == 0 ||
1539 piece == WhiteKnight && rt > BOARD_HEIGHT-3 ||
1540 piece == BlackKnight && rt < 2 ) return IllegalMove; // e.g. where dropped piece has no moves
1541 if(piece == WhitePawn || piece == BlackPawn) {
1542 int r, max = 1 + (BOARD_HEIGHT == 7); // two Pawns per file in Tori!
1543 for(r=1; r<BOARD_HEIGHT-1; r++)
1544 if(!(max -= (board[r][ft] == piece))) return IllegalMove; // or there already is a Pawn in file
1545 // should still test if we mate with this Pawn
1547 } else if(gameInfo.variant == VariantSChess) { // only back-rank drops
1548 if (rt != (piece < BlackPawn ? 0 : BOARD_HEIGHT-1)) return IllegalMove;
1550 if( (piece == WhitePawn || piece == BlackPawn) &&
1551 (rt == 0 || rt == BOARD_HEIGHT -1 ) )
1552 return IllegalMove; /* no pawn drops on 1st/8th */
1554 if(appData.debugMode) fprintf(debugFP, "LegalDrop: %d @ %d,%d)\n", piece, ft, rt);
1555 if (!(flags & F_IGNORE_CHECK) &&
1556 CheckTest(board, flags, DROP_RANK, piece, rt, ft, FALSE) ) return IllegalMove;
1557 return flags & F_WHITE_ON_MOVE ? WhiteDrop : BlackDrop;
1560 extern void LegalityTestCallback P((Board board, int flags, ChessMove kind,
1561 int rf, int ff, int rt, int ft,
1565 LegalityTestCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1567 register LegalityTestClosure *cl = (LegalityTestClosure *) closure;
1569 if(board[rt][ft] != EmptySquare || kind==WhiteCapturesEnPassant || kind==BlackCapturesEnPassant)
1570 cl->captures++; // [HGM] losers: count legal captures
1571 if (rf == cl->rf && ff == cl->ff && rt == cl->rt && ft == cl->ft)
1576 LegalityTest (Board board, int flags, int rf, int ff, int rt, int ft, int promoChar)
1578 LegalityTestClosure cl; ChessSquare piece, filterPiece;
1580 if(quickFlag) flags = flags & ~1 | quickFlag & 1; // [HGM] speed: in quick mode quickFlag specifies side-to-move.
1581 if(rf == DROP_RANK) return LegalDrop(board, flags, ff, rt, ft);
1582 piece = filterPiece = board[rf][ff];
1583 if(PieceToChar(piece) == '~') filterPiece = DEMOTED piece;
1585 /* [HGM] Cobra and Falcon are wildcard pieces; consider all their moves legal */
1586 /* (perhaps we should disallow moves that obviously leave us in check?) */
1587 if((piece == WhiteFalcon || piece == BlackFalcon ||
1588 piece == WhiteCobra || piece == BlackCobra) && gameInfo.variant != VariantChu)
1589 return CheckTest(board, flags, rf, ff, rt, ft, FALSE) ? IllegalMove : NormalMove;
1593 cl.rt = rFilter = rt; // [HGM] speed: filter on to-square
1594 cl.ft = fFilter = ft;
1595 cl.kind = IllegalMove;
1596 cl.captures = 0; // [HGM] losers: prepare to count legal captures.
1597 if(flags & F_MANDATORY_CAPTURE) filterPiece = EmptySquare; // [HGM] speed: do not filter in suicide, to find all captures
1598 GenLegal(board, flags, LegalityTestCallback, (VOIDSTAR) &cl, filterPiece);
1599 if((flags & F_MANDATORY_CAPTURE) && cl.captures && board[rt][ft] == EmptySquare
1600 && cl.kind != WhiteCapturesEnPassant && cl.kind != BlackCapturesEnPassant)
1601 return(IllegalMove); // [HGM] losers: if there are legal captures, non-capts are illegal
1603 if(promoChar == 'x') promoChar = NULLCHAR; // [HGM] is this ever the case?
1604 if(gameInfo.variant == VariantSChess && promoChar && promoChar != '=' && board[rf][ff] != WhitePawn && board[rf][ff] != BlackPawn) {
1605 if(board[rf][ff] < BlackPawn) { // white
1606 if(rf != 0) return IllegalMove; // must be on back rank
1607 if(!(board[VIRGIN][ff] & VIRGIN_W)) return IllegalMove; // non-virgin
1608 if(board[PieceToNumber(CharToPiece(ToUpper(promoChar)))][BOARD_WIDTH-2] == 0) return ImpossibleMove;// must be in stock
1609 if(cl.kind == WhiteHSideCastleFR && (ff == BOARD_RGHT-2 || ff == BOARD_RGHT-3)) return ImpossibleMove;
1610 if(cl.kind == WhiteASideCastleFR && (ff == BOARD_LEFT+2 || ff == BOARD_LEFT+3)) return ImpossibleMove;
1612 if(rf != BOARD_HEIGHT-1) return IllegalMove;
1613 if(!(board[VIRGIN][ff] & VIRGIN_B)) return IllegalMove; // non-virgin
1614 if(board[BOARD_HEIGHT-1-PieceToNumber(CharToPiece(ToLower(promoChar)))][1] == 0) return ImpossibleMove;
1615 if(cl.kind == BlackHSideCastleFR && (ff == BOARD_RGHT-2 || ff == BOARD_RGHT-3)) return ImpossibleMove;
1616 if(cl.kind == BlackASideCastleFR && (ff == BOARD_LEFT+2 || ff == BOARD_LEFT+3)) return ImpossibleMove;
1619 if(gameInfo.variant == VariantChu) {
1620 if(cl.kind != NormalMove || promoChar == NULLCHAR || promoChar == '=') return cl.kind;
1621 if(promoChar != '+')
1622 return CharToPiece(promoChar) == EmptySquare ? ImpossibleMove : IllegalMove;
1623 if(PieceToChar(CHUPROMOTED board[rf][ff]) != '+') return ImpossibleMove;
1624 return flags & F_WHITE_ON_MOVE ? WhitePromotion : BlackPromotion;
1626 if(gameInfo.variant == VariantShogi) {
1627 /* [HGM] Shogi promotions. '=' means defer */
1628 if(rf != DROP_RANK && cl.kind == NormalMove) {
1629 ChessSquare piece = board[rf][ff];
1631 if(promoChar == PieceToChar(BlackQueen)) promoChar = NULLCHAR; /* [HGM] Kludge */
1632 if(promoChar == 'd' && (piece == WhiteRook || piece == BlackRook) ||
1633 promoChar == 'h' && (piece == WhiteBishop || piece == BlackBishop) ||
1634 promoChar == 'g' && (piece <= WhiteFerz || piece <= BlackFerz && piece >= BlackPawn) )
1635 promoChar = '+'; // allowed ICS notations
1636 if(appData.debugMode)fprintf(debugFP,"SHOGI promoChar = %c\n", promoChar ? promoChar : '-');
1637 if(promoChar != NULLCHAR && promoChar != '+' && promoChar != '=')
1638 return CharToPiece(promoChar) == EmptySquare ? ImpossibleMove : IllegalMove;
1639 else if(flags & F_WHITE_ON_MOVE) {
1640 if( (int) piece < (int) WhiteWazir &&
1641 (rf >= BOARD_HEIGHT - BOARD_HEIGHT/3 || rt >= BOARD_HEIGHT - BOARD_HEIGHT/3) ) {
1642 if( (piece == WhitePawn || piece == WhiteQueen) && rt > BOARD_HEIGHT-2 ||
1643 piece == WhiteKnight && rt > BOARD_HEIGHT-3) /* promotion mandatory */
1644 cl.kind = promoChar == '=' ? IllegalMove : WhitePromotion;
1645 else /* promotion optional, default is defer */
1646 cl.kind = promoChar == '+' ? WhitePromotion : WhiteNonPromotion;
1647 } else cl.kind = promoChar == '+' ? IllegalMove : NormalMove;
1649 if( (int) piece < (int) BlackWazir && (rf < BOARD_HEIGHT/3 || rt < BOARD_HEIGHT/3) ) {
1650 if( (piece == BlackPawn || piece == BlackQueen) && rt < 1 ||
1651 piece == BlackKnight && rt < 2 ) /* promotion obligatory */
1652 cl.kind = promoChar == '=' ? IllegalMove : BlackPromotion;
1653 else /* promotion optional, default is defer */
1654 cl.kind = promoChar == '+' ? BlackPromotion : BlackNonPromotion;
1655 } else cl.kind = promoChar == '+' ? IllegalMove : NormalMove;
1659 if (promoChar != NULLCHAR) {
1660 if(cl.kind == NormalMove && promoChar == '+') { // allow shogi-style promotion is pieceToChar specifies them
1661 ChessSquare piece = board[rf][ff];
1662 if(piece < BlackPawn ? piece > WhiteMan : piece > BlackMan) return ImpossibleMove; // already promoted
1663 // should test if in zone, really
1664 if(gameInfo.variant == VariantChuChess && (piece == WhiteKnight || piece == BlackKnight) && HasLion(board, flags))
1666 if(PieceToChar(PROMOTED piece) == '+') return flags & F_WHITE_ON_MOVE ? WhitePromotion : BlackPromotion;
1668 if(promoChar == '=') cl.kind = IllegalMove; else // [HGM] shogi: no deferred promotion outside Shogi
1669 if (cl.kind == WhitePromotion || cl.kind == BlackPromotion) {
1670 ChessSquare piece = CharToPiece(flags & F_WHITE_ON_MOVE ? ToUpper(promoChar) : ToLower(promoChar));
1671 if(piece == EmptySquare)
1672 cl.kind = ImpossibleMove; // non-existing piece
1673 if(gameInfo.variant == VariantChuChess && promoChar == 'l' && HasLion(board, flags)) {
1674 cl.kind = IllegalMove; // no two Lions
1675 } else if(gameInfo.variant == VariantSpartan && cl.kind == BlackPromotion ) {
1676 if(promoChar != PieceToChar(BlackKing)) {
1677 if(CheckTest(board, flags, rf, ff, rt, ft, FALSE)) cl.kind = IllegalMove; // [HGM] spartan: only promotion to King was possible
1678 if(piece == BlackLance) cl.kind = ImpossibleMove;
1679 } else { // promotion to King allowed only if we do not have two yet
1680 int r, f, kings = 0;
1681 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++) kings += (board[r][f] == BlackKing);
1682 if(kings == 2) cl.kind = IllegalMove;
1684 } else if(piece == WhitePawn && rt == BOARD_HEIGHT-1 ||
1685 piece == BlackPawn && rt == 0) cl.kind = IllegalMove; // cannot stay Pawn on last rank in any variant
1686 else if((piece == WhiteUnicorn || piece == BlackUnicorn) && gameInfo.variant == VariantKnightmate)
1687 cl.kind = IllegalMove; // promotion to Royal Knight not allowed
1688 else if((piece == WhiteKing || piece == BlackKing) && gameInfo.variant != VariantSuicide && gameInfo.variant != VariantGiveaway)
1689 cl.kind = IllegalMove; // promotion to King usually not allowed
1691 cl.kind = IllegalMove;
1701 extern void MateTestCallback P((Board board, int flags, ChessMove kind,
1702 int rf, int ff, int rt, int ft,
1706 MateTestCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1708 register MateTestClosure *cl = (MateTestClosure *) closure;
1713 /* Return MT_NONE, MT_CHECK, MT_CHECKMATE, or MT_STALEMATE */
1715 MateTest (Board board, int flags)
1718 int inCheck, r, f, myPieces=0, hisPieces=0, nrKing=0;
1719 ChessSquare king = flags & F_WHITE_ON_MOVE ? WhiteKing : BlackKing;
1721 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++) {
1722 // [HGM] losers: Count pieces and kings, to detect other unorthodox winning conditions
1723 nrKing += (board[r][f] == king); // stm has king
1724 if( board[r][f] != EmptySquare ) {
1725 if((int)board[r][f] <= (int)king && (int)board[r][f] >= (int)king - (int)WhiteKing + (int)WhitePawn)
1730 switch(gameInfo.variant) { // [HGM] losers: extinction wins
1731 case VariantShatranj:
1732 if(hisPieces == 1) return myPieces > 1 ? MT_BARE : MT_DRAW;
1736 if(nrKing == 0) return MT_NOKING;
1739 if(myPieces == 1) return MT_BARE;
1742 inCheck = GenLegal(board, flags, MateTestCallback, (VOIDSTAR) &cl, EmptySquare);
1743 // [HGM] 3check: yet to do!
1745 return inCheck ? MT_CHECK : MT_NONE;
1747 if(gameInfo.holdingsWidth && gameInfo.variant != VariantSuper && gameInfo.variant != VariantGreat
1748 && gameInfo.variant != VariantSChess && gameInfo.variant != VariantGrand) { // drop game
1749 int r, f, n, holdings = flags & F_WHITE_ON_MOVE ? BOARD_WIDTH-1 : 0;
1750 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++) if(board[r][f] == EmptySquare) // all empty squares
1751 for(n=0; n<BOARD_HEIGHT; n++) // all pieces in hand
1752 if(board[n][holdings] != EmptySquare) {
1753 int moveType = LegalDrop(board, flags, board[n][holdings], r, f);
1754 if(moveType == WhiteDrop || moveType == BlackDrop) return (inCheck ? MT_CHECK : MT_NONE); // we have legal drop
1757 if(gameInfo.variant == VariantSuicide) // [HGM] losers: always stalemate, since no check, but result varies
1758 return myPieces == hisPieces ? MT_STALEMATE :
1759 myPieces > hisPieces ? MT_STAINMATE : MT_STEALMATE;
1760 else if(gameInfo.variant == VariantLosers) return inCheck ? MT_TRICKMATE : MT_STEALMATE;
1761 else if(gameInfo.variant == VariantGiveaway) return MT_STEALMATE; // no check exists, stalemated = win
1763 return inCheck ? MT_CHECKMATE
1764 : (gameInfo.variant == VariantXiangqi || gameInfo.variant == VariantShatranj || IS_SHOGI(gameInfo.variant)) ?
1765 MT_STAINMATE : MT_STALEMATE;
1770 extern void DisambiguateCallback P((Board board, int flags, ChessMove kind,
1771 int rf, int ff, int rt, int ft,
1775 DisambiguateCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1777 register DisambiguateClosure *cl = (DisambiguateClosure *) closure;
1778 int wildCard = FALSE; ChessSquare piece = board[rf][ff];
1780 // [HGM] wild: for wild-card pieces rt and rf are dummies
1781 if(piece == WhiteFalcon || piece == BlackFalcon ||
1782 piece == WhiteCobra || piece == BlackCobra)
1785 if ((cl->pieceIn == EmptySquare || cl->pieceIn == board[rf][ff]
1786 || PieceToChar(board[rf][ff]) == '~'
1787 && cl->pieceIn == (ChessSquare)(DEMOTED board[rf][ff])
1789 (cl->rfIn == -1 || cl->rfIn == rf) &&
1790 (cl->ffIn == -1 || cl->ffIn == ff) &&
1791 (cl->rtIn == -1 || cl->rtIn == rt || wildCard) &&
1792 (cl->ftIn == -1 || cl->ftIn == ft || wildCard)) {
1795 if(cl->count == 1 || board[rt][ft] != EmptySquare) {
1796 // [HGM] oneclick: if multiple moves, be sure we remember capture
1797 cl->piece = board[rf][ff];
1800 cl->rt = wildCard ? cl->rtIn : rt;
1801 cl->ft = wildCard ? cl->ftIn : ft;
1804 cl->captures += (board[rt][ft] != EmptySquare); // [HGM] oneclick: count captures
1809 Disambiguate (Board board, int flags, DisambiguateClosure *closure)
1811 int illegal = 0; char c = closure->promoCharIn;
1813 if(quickFlag) flags = flags & ~1 | quickFlag & 1; // [HGM] speed: in quick mode quickFlag specifies side-to-move.
1814 closure->count = closure->captures = 0;
1815 closure->rf = closure->ff = closure->rt = closure->ft = 0;
1816 closure->kind = ImpossibleMove;
1817 rFilter = closure->rtIn; // [HGM] speed: only consider moves to given to-square
1818 fFilter = closure->ftIn;
1819 if(quickFlag) { // [HGM] speed: try without check test first, because if that is not ambiguous, we are happy
1820 GenLegal(board, flags|F_IGNORE_CHECK, DisambiguateCallback, (VOIDSTAR) closure, closure->pieceIn);
1821 if(closure->count > 1) { // gamble did not pay off. retry with check test to resolve ambiguity
1822 closure->count = closure->captures = 0;
1823 closure->rf = closure->ff = closure->rt = closure->ft = 0;
1824 closure->kind = ImpossibleMove;
1825 GenLegal(board, flags, DisambiguateCallback, (VOIDSTAR) closure, closure->pieceIn); // [HGM] speed: only pieces of requested type
1828 GenLegal(board, flags, DisambiguateCallback, (VOIDSTAR) closure, closure->pieceIn); // [HGM] speed: only pieces of requested type
1829 if (closure->count == 0) {
1830 /* See if it's an illegal move due to check */
1832 GenLegal(board, flags|F_IGNORE_CHECK, DisambiguateCallback, (VOIDSTAR) closure, closure->pieceIn);
1833 if (closure->count == 0) {
1834 /* No, it's not even that */
1835 if(!appData.testLegality && closure->pieceIn != EmptySquare) {
1836 int f, r; // if there is only a single piece of the requested type on the board, use that
1837 closure->rt = closure->rtIn, closure->ft = closure->ftIn;
1838 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++)
1839 if(board[r][f] == closure->pieceIn) closure->count++, closure->rf = r, closure->ff = f;
1840 if(closure->count > 1) illegal = 0; // ambiguous
1842 if(closure->count == 0) {
1843 if (appData.debugMode) { int i, j;
1844 for(i=BOARD_HEIGHT-1; i>=0; i--) {
1845 for(j=0; j<BOARD_WIDTH; j++)
1846 fprintf(debugFP, "%3d", (int) board[i][j]);
1847 fprintf(debugFP, "\n");
1855 if (c == 'x') c = NULLCHAR; // get rid of any 'x' (which should never happen?)
1856 if(gameInfo.variant == VariantSChess && c && c != '=' && closure->piece != WhitePawn && closure->piece != BlackPawn) {
1857 if(closure->piece < BlackPawn) { // white
1858 if(closure->rf != 0) closure->kind = IllegalMove; // must be on back rank
1859 if(!(board[VIRGIN][closure->ff] & VIRGIN_W)) closure->kind = IllegalMove; // non-virgin
1860 if(board[PieceToNumber(CharToPiece(ToUpper(c)))][BOARD_WIDTH-2] == 0) closure->kind = ImpossibleMove;// must be in stock
1861 if(closure->kind == WhiteHSideCastleFR && (closure->ff == BOARD_RGHT-2 || closure->ff == BOARD_RGHT-3)) closure->kind = ImpossibleMove;
1862 if(closure->kind == WhiteASideCastleFR && (closure->ff == BOARD_LEFT+2 || closure->ff == BOARD_LEFT+3)) closure->kind = ImpossibleMove;
1864 if(closure->rf != BOARD_HEIGHT-1) closure->kind = IllegalMove;
1865 if(!(board[VIRGIN][closure->ff] & VIRGIN_B)) closure->kind = IllegalMove; // non-virgin
1866 if(board[BOARD_HEIGHT-1-PieceToNumber(CharToPiece(ToLower(c)))][1] == 0) closure->kind = ImpossibleMove;
1867 if(closure->kind == BlackHSideCastleFR && (closure->ff == BOARD_RGHT-2 || closure->ff == BOARD_RGHT-3)) closure->kind = ImpossibleMove;
1868 if(closure->kind == BlackASideCastleFR && (closure->ff == BOARD_LEFT+2 || closure->ff == BOARD_LEFT+3)) closure->kind = ImpossibleMove;
1871 if(gameInfo.variant == VariantChu) {
1872 if(c == '+') closure->kind = (flags & F_WHITE_ON_MOVE ? WhitePromotion : BlackPromotion); // for now, accept any
1874 if(gameInfo.variant == VariantShogi) {
1875 /* [HGM] Shogi promotions. On input, '=' means defer, '+' promote. Afterwards, c is set to '+' for promotions, NULL other */
1876 if(closure->rfIn != DROP_RANK && closure->kind == NormalMove) {
1877 ChessSquare piece = closure->piece;
1878 if (c == 'd' && (piece == WhiteRook || piece == BlackRook) ||
1879 c == 'h' && (piece == WhiteBishop || piece == BlackBishop) ||
1880 c == 'g' && (piece <= WhiteFerz || piece <= BlackFerz && piece >= BlackPawn) )
1881 c = '+'; // allowed ICS notations
1882 if(c != NULLCHAR && c != '+' && c != '=') closure->kind = IllegalMove; // otherwise specifying a piece is illegal
1883 else if(flags & F_WHITE_ON_MOVE) {
1884 if( (int) piece < (int) WhiteWazir &&
1885 (closure->rf >= BOARD_HEIGHT-(BOARD_HEIGHT/3) || closure->rt >= BOARD_HEIGHT-(BOARD_HEIGHT/3)) ) {
1886 if( (piece == WhitePawn || piece == WhiteQueen) && closure->rt > BOARD_HEIGHT-2 ||
1887 piece == WhiteKnight && closure->rt > BOARD_HEIGHT-3) /* promotion mandatory */
1888 closure->kind = c == '=' ? IllegalMove : WhitePromotion;
1889 else /* promotion optional, default is defer */
1890 closure->kind = c == '+' ? WhitePromotion : WhiteNonPromotion;
1891 } else closure->kind = c == '+' ? IllegalMove : NormalMove;
1893 if( (int) piece < (int) BlackWazir && (closure->rf < BOARD_HEIGHT/3 || closure->rt < BOARD_HEIGHT/3) ) {
1894 if( (piece == BlackPawn || piece == BlackQueen) && closure->rt < 1 ||
1895 piece == BlackKnight && closure->rt < 2 ) /* promotion obligatory */
1896 closure->kind = c == '=' ? IllegalMove : BlackPromotion;
1897 else /* promotion optional, default is defer */
1898 closure->kind = c == '+' ? BlackPromotion : BlackNonPromotion;
1899 } else closure->kind = c == '+' ? IllegalMove : NormalMove;
1902 if(closure->kind == WhitePromotion || closure->kind == BlackPromotion) c = '+'; else
1903 if(closure->kind == WhiteNonPromotion || closure->kind == BlackNonPromotion) c = '=';
1905 if (closure->kind == WhitePromotion || closure->kind == BlackPromotion) {
1906 if(c == NULLCHAR) { // missing promoChar on mandatory promotion; use default for variant
1907 if(gameInfo.variant == VariantShatranj || gameInfo.variant == VariantCourier ||
1908 gameInfo.variant == VariantMakruk || gameInfo.variant == VariantASEAN)
1909 c = PieceToChar(BlackFerz);
1910 else if(gameInfo.variant == VariantGreat)
1911 c = PieceToChar(BlackMan);
1912 else if(gameInfo.variant == VariantGrand)
1913 closure->kind = closure->rt != 0 && closure->rt != BOARD_HEIGHT-1 ? NormalMove : AmbiguousMove; // no default in Grand Chess
1915 c = PieceToChar(BlackQueen);
1916 } else if(c == '=') closure->kind = IllegalMove; // no deferral outside Shogi
1917 else if(c == 'l' && gameInfo.variant == VariantChuChess && HasLion(board, flags)) closure->kind = IllegalMove;
1918 } else if (c == '+') { // '+' outside shogi, check if pieceToCharTable enabled it
1919 ChessSquare p = closure->piece;
1920 if(p > WhiteMan && p < BlackPawn || p > BlackMan || PieceToChar(PROMOTED p) != '+')
1921 closure->kind = ImpossibleMove; // used on non-promotable piece
1922 else if(gameInfo.variant == VariantChuChess && HasLion(board, flags)) closure->kind = IllegalMove;
1923 } else if (c != NULLCHAR) closure->kind = IllegalMove;
1925 closure->promoChar = ToLower(c); // this can be NULLCHAR! Note we keep original promoChar even if illegal.
1926 if(c != '+' && c != '=' && c != NULLCHAR && CharToPiece(flags & F_WHITE_ON_MOVE ? ToUpper(c) : ToLower(c)) == EmptySquare)
1927 closure->kind = ImpossibleMove; // but we cannot handle non-existing piece types!
1928 if (closure->count > 1) {
1929 closure->kind = AmbiguousMove;
1932 /* Note: If more than one illegal move matches, but no legal
1933 moves, we return IllegalMove, not AmbiguousMove. Caller
1934 can look at closure->count to detect this.
1936 closure->kind = IllegalMove;
1950 } CoordsToAlgebraicClosure;
1952 extern void CoordsToAlgebraicCallback P((Board board, int flags,
1953 ChessMove kind, int rf, int ff,
1954 int rt, int ft, VOIDSTAR closure));
1957 CoordsToAlgebraicCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1959 register CoordsToAlgebraicClosure *cl =
1960 (CoordsToAlgebraicClosure *) closure;
1962 if ((rt == cl->rt && ft == cl->ft || rt == rf && ft == ff) && // [HGM] null move matches any toSquare
1963 (board[rf][ff] == cl->piece
1964 || PieceToChar(board[rf][ff]) == '~' &&
1965 (ChessSquare) (DEMOTED board[rf][ff]) == cl->piece)
1969 cl->kind = kind; /* this is the move we want */
1971 cl->file++; /* need file to rule out this move */
1975 cl->rank++; /* need rank to rule out this move */
1977 cl->either++; /* rank or file will rule out this move */
1983 /* Convert coordinates to normal algebraic notation.
1984 promoChar must be NULLCHAR or 'x' if not a promotion.
1987 CoordsToAlgebraic (Board board, int flags, int rf, int ff, int rt, int ft, int promoChar, char out[MOVE_LEN])
1991 char *outp = out, c, capture;
1992 CoordsToAlgebraicClosure cl;
1994 if (rf == DROP_RANK) {
1995 if(ff == EmptySquare) { strncpy(outp, "--",3); return NormalMove; } // [HGM] pass
1996 /* Bughouse piece drop */
1997 *outp++ = ToUpper(PieceToChar((ChessSquare) ff));
2002 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2004 return (flags & F_WHITE_ON_MOVE) ? WhiteDrop : BlackDrop;
2007 if (promoChar == 'x') promoChar = NULLCHAR;
2008 piece = board[rf][ff];
2009 if(PieceToChar(piece)=='~') piece = (ChessSquare)(DEMOTED piece);
2014 kind = LegalityTest(board, flags, rf, ff, rt, ft, promoChar);
2015 if (kind == IllegalMove && !(flags&F_IGNORE_CHECK)) {
2016 /* Keep short notation if move is illegal only because it
2017 leaves the player in check, but still return IllegalMove */
2018 kind = LegalityTest(board, flags|F_IGNORE_CHECK, rf, ff, rt, ft, promoChar);
2019 if (kind == IllegalMove) break;
2024 capture = board[rt][ft] != EmptySquare || kind == WhiteCapturesEnPassant || kind == BlackCapturesEnPassant;
2025 if (ff == ft && !capture) { /* [HGM] Xiangqi has straight noncapts! */
2026 /* Non-capture; use style "e5" */
2029 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2031 /* Capture; use style "exd5" */
2033 *outp++ = 'x'; /* [HGM] Xiangqi has sideway noncaptures across river! */
2037 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2039 /* Use promotion suffix style "=Q" */
2041 if (promoChar != NULLCHAR) {
2042 if(IS_SHOGI(gameInfo.variant)) {
2043 /* [HGM] ... but not in Shogi! */
2044 *outp++ = promoChar == '=' ? '=' : '+';
2047 *outp++ = ToUpper(promoChar);
2056 /* Fabien moved code: FRC castling first (if KxR), wild castling second */
2057 /* Code added by Tord: FRC castling. */
2058 if((piece == WhiteKing && board[rt][ft] == WhiteRook) ||
2059 (piece == BlackKing && board[rt][ft] == BlackRook)) {
2061 safeStrCpy(out, "O-O", MOVE_LEN);
2063 safeStrCpy(out, "O-O-O", MOVE_LEN);
2064 return LegalityTest(board, flags, rf, ff, rt, ft, promoChar);
2066 /* End of code added by Tord */
2067 /* Test for castling or ICS wild castling */
2068 /* Use style "O-O" (oh-oh) for PGN compatibility */
2069 else if (rf == rt &&
2070 rf == ((piece == WhiteKing) ? 0 : BOARD_HEIGHT-1) &&
2071 (ft - ff > 1 || ff - ft > 1) && // No castling if legal King move (on narrow boards!)
2072 ((ff == BOARD_WIDTH>>1 && (ft == BOARD_LEFT+2 || ft == BOARD_RGHT-2)) ||
2073 (ff == (BOARD_WIDTH-1)>>1 && (ft == BOARD_LEFT+1 || ft == BOARD_RGHT-3)))) {
2074 if(ft==BOARD_LEFT+1 || ft==BOARD_RGHT-2)
2075 snprintf(out, MOVE_LEN, "O-O%c%c", promoChar ? '/' : 0, ToUpper(promoChar));
2077 snprintf(out, MOVE_LEN, "O-O-O%c%c", promoChar ? '/' : 0, ToUpper(promoChar));
2079 /* This notation is always unambiguous, unless there are
2080 kings on both the d and e files, with "wild castling"
2081 possible for the king on the d file and normal castling
2082 possible for the other. ICS rules for wild 9
2083 effectively make castling illegal for either king in
2084 this situation. So I am not going to worry about it;
2085 I'll just generate an ambiguous O-O in this case.
2087 return LegalityTest(board, flags, rf, ff, rt, ft, promoChar);
2090 /* else fall through */
2095 cl.rt = rFilter = rt; // [HGM] speed: filter on to-square
2096 cl.ft = fFilter = ft;
2098 cl.kind = IllegalMove;
2099 cl.rank = cl.file = cl.either = 0;
2100 c = PieceToChar(piece) ;
2101 GenLegal(board, flags, CoordsToAlgebraicCallback, (VOIDSTAR) &cl, c!='~' ? piece : (DEMOTED piece)); // [HGM] speed
2103 if (cl.kind == IllegalMove && !(flags&F_IGNORE_CHECK)) {
2104 /* Generate pretty moves for moving into check, but
2105 still return IllegalMove.
2107 GenLegal(board, flags|F_IGNORE_CHECK, CoordsToAlgebraicCallback, (VOIDSTAR) &cl, c!='~' ? piece : (DEMOTED piece));
2108 if (cl.kind == IllegalMove) break;
2109 cl.kind = IllegalMove;
2112 /* Style is "Nf3" or "Nxf7" if this is unambiguous,
2113 else "Ngf3" or "Ngxf7",
2114 else "N1f3" or "N5xf7",
2115 else "Ng1f3" or "Ng5xf7".
2117 if( c == '~' || c == '+') {
2118 /* [HGM] print nonexistent piece as its demoted version */
2119 piece = (ChessSquare) (DEMOTED piece - 11*(gameInfo.variant == VariantChu));
2121 if(c=='+') *outp++ = c;
2122 *outp++ = ToUpper(PieceToChar(piece));
2124 if (cl.file || (cl.either && !cl.rank)) {
2130 else { *outp++ = (rf+ONE-'0')/10 + '0';*outp++ = (rf+ONE-'0')%10 + '0'; }
2133 if(board[rt][ft] != EmptySquare)
2139 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2140 if (IS_SHOGI(gameInfo.variant)) {
2141 /* [HGM] in Shogi non-pawns can promote */
2142 *outp++ = promoChar; // Don't bother to correct move type, return value is never used!
2144 else if (gameInfo.variant == VariantChuChess && promoChar ||
2145 gameInfo.variant != VariantSuper && promoChar &&
2146 (piece == WhiteLance || piece == BlackLance) ) { // Lance sometimes represents Pawn
2148 *outp++ = ToUpper(promoChar);
2150 else if (gameInfo.variant == VariantSChess && promoChar) { // and in S-Chess we have gating
2152 *outp++ = ToUpper(promoChar);
2158 /* Moving a nonexistent piece */
2162 /* Not a legal move, even ignoring check.
2163 If there was a piece on the from square,
2164 use style "Ng1g3" or "Ng1xe8";
2165 if there was a pawn or nothing (!),
2166 use style "g1g3" or "g1xe8". Use "x"
2167 if a piece was on the to square, even
2168 a piece of the same color.
2172 if (piece != EmptySquare && piece != WhitePawn && piece != BlackPawn) {
2174 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<=BOARD_RGHT; f++)
2175 c += (board[r][f] == piece); // count on-board pieces of given type
2176 *outp++ = ToUpper(PieceToChar(piece));
2178 if(c != 1) { // [HGM] but if there is only one piece of the mentioned type, no from-square, thank you!
2182 else { *outp++ = (rf+ONE-'0')/10 + '0';*outp++ = (rf+ONE-'0')%10 + '0'; }
2184 if (board[rt][ft] != EmptySquare) *outp++ = 'x';
2188 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2189 /* Use promotion suffix style "=Q" */
2190 if (promoChar != NULLCHAR && promoChar != 'x') {
2192 *outp++ = ToUpper(promoChar);
2199 // [HGM] XQ: the following code serves to detect perpetual chasing (Asian rules)
2208 // I guess the following variables logically belong in the closure too, but I was too lazy and used globals
2210 int preyStackPointer, chaseStackPointer;
2213 unsigned char rf, ff, rt, ft;
2217 unsigned char rank, file;
2223 // there are three new callbacks for use with GenLegal: for adding captures, deleting them, and finding a recapture
2225 extern void AtacksCallback P((Board board, int flags, ChessMove kind,
2226 int rf, int ff, int rt, int ft,
2230 AttacksCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
2231 { // For adding captures that can lead to chase indictment to the chaseStack
2232 if(board[rt][ft] == EmptySquare) return; // non-capture
2233 if(board[rt][ft] == WhitePawn && rt < BOARD_HEIGHT/2) return; // Pawn before river can be chased
2234 if(board[rt][ft] == BlackPawn && rt >= BOARD_HEIGHT/2) return; // Pawn before river can be chased
2235 if(board[rf][ff] == WhitePawn || board[rf][ff] == BlackPawn) return; // Pawns are allowed to chase
2236 if(board[rf][ff] == WhiteWazir || board[rf][ff] == BlackWazir) return; // King is allowed to chase
2237 // move cannot be excluded from being a chase trivially (based on attacker and victim); save it on chaseStack
2238 chaseStack[chaseStackPointer].rf = rf;
2239 chaseStack[chaseStackPointer].ff = ff;
2240 chaseStack[chaseStackPointer].rt = rt;
2241 chaseStack[chaseStackPointer].ft = ft;
2242 chaseStackPointer++;
2245 extern void ExistingAtacksCallback P((Board board, int flags, ChessMove kind,
2246 int rf, int ff, int rt, int ft,
2250 ExistingAttacksCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
2251 { // for removing pre-exsting captures from the chaseStack, to be left with newly created ones
2253 register ChaseClosure *cl = (ChaseClosure *) closure; //closure tells us the move played in the repeat loop
2255 if(board[rt][ft] == EmptySquare) return; // no capture
2256 if(rf == cl->rf && ff == cl->ff) { // attacks with same piece from new position are not considered new
2257 rf = cl->rt; ff = cl->ft; // doctor their fromSquare so they will be recognized in chaseStack
2259 // search move in chaseStack, and delete it if it occurred there (as we know now it is not a new capture)
2260 for(i=0; i<chaseStackPointer; i++) {
2261 if(chaseStack[i].rf == rf && chaseStack[i].ff == ff &&
2262 chaseStack[i].rt == rt && chaseStack[i].ft == ft ) {
2263 // move found on chaseStack, delete it by overwriting with move popped from top of chaseStack
2264 chaseStack[i] = chaseStack[--chaseStackPointer];
2270 extern void ProtectedCallback P((Board board, int flags, ChessMove kind,
2271 int rf, int ff, int rt, int ft,
2275 ProtectedCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
2276 { // for determining if a piece (given through the closure) is protected
2277 register ChaseClosure *cl = (ChaseClosure *) closure; // closure tells us where to recapture
2279 if(rt == cl->rt && ft == cl->ft) cl->recaptures++; // count legal recaptures to this square
2280 if(appData.debugMode && board[rt][ft] != EmptySquare)
2281 fprintf(debugFP, "try %c%c%c%c=%d\n", ff+AAA, rf+ONE,ft+AAA, rt+ONE, cl->recaptures);
2284 extern char moveList[MAX_MOVES][MOVE_LEN];
2287 PerpetualChase (int first, int last)
2288 { // this routine detects if the side to move in the 'first' position is perpetually chasing (when not checking)
2291 ChessSquare captured;
2293 preyStackPointer = 0; // clear stack of chased pieces
2294 for(i=first; i<last; i+=2) { // for all positions with same side to move
2295 if(appData.debugMode) fprintf(debugFP, "judge position %i\n", i);
2296 chaseStackPointer = 0; // clear stack that is going to hold possible chases
2297 // determine all captures possible after the move, and put them on chaseStack
2298 GenLegal(boards[i+1], PosFlags(i), AttacksCallback, &cl, EmptySquare);
2299 if(appData.debugMode) { int n;
2300 for(n=0; n<chaseStackPointer; n++)
2301 fprintf(debugFP, "%c%c%c%c ", chaseStack[n].ff+AAA, chaseStack[n].rf+ONE,
2302 chaseStack[n].ft+AAA, chaseStack[n].rt+ONE);
2303 fprintf(debugFP, ": all capts\n");
2305 // determine all captures possible before the move, and delete them from chaseStack
2306 cl.rf = moveList[i][1]-ONE; // prepare closure to pass move that led from i to i+1
2307 cl.ff = moveList[i][0]-AAA+BOARD_LEFT;
2308 cl.rt = moveList[i][3]-ONE;
2309 cl.ft = moveList[i][2]-AAA+BOARD_LEFT;
2310 CopyBoard(xqCheckers, nullBoard); xqCheckers[EP_STATUS] = 1; // giant kludge to make GenLegal ignore pre-existing checks
2311 GenLegal(boards[i], PosFlags(i), ExistingAttacksCallback, &cl, EmptySquare);
2312 xqCheckers[EP_STATUS] = 0; // disable the generation of quasi-legal moves again
2313 if(appData.debugMode) { int n;
2314 for(n=0; n<chaseStackPointer; n++)
2315 fprintf(debugFP, "%c%c%c%c ", chaseStack[n].ff+AAA, chaseStack[n].rf+ONE,
2316 chaseStack[n].ft+AAA, chaseStack[n].rt+ONE);
2317 fprintf(debugFP, ": new capts after %c%c%c%c\n", cl.ff+AAA, cl.rf+ONE, cl.ft+AAA, cl.rt+ONE);
2319 // chaseSack now contains all captures made possible by the move
2320 for(j=0; j<chaseStackPointer; j++) { // run through chaseStack to identify true chases
2321 int attacker = (int)boards[i+1][chaseStack[j].rf][chaseStack[j].ff];
2322 int victim = (int)boards[i+1][chaseStack[j].rt][chaseStack[j].ft];
2324 if(attacker >= (int) BlackPawn) attacker = BLACK_TO_WHITE attacker; // convert to white, as piecee type
2325 if(victim >= (int) BlackPawn) victim = BLACK_TO_WHITE victim;
2327 if((attacker == WhiteKnight || attacker == WhiteCannon) && victim == WhiteRook)
2328 continue; // C or H attack on R is always chase; leave on chaseStack
2330 if(attacker == victim) {
2331 if(LegalityTest(boards[i+1], PosFlags(i+1), chaseStack[j].rt,
2332 chaseStack[j].ft, chaseStack[j].rf, chaseStack[j].ff, NULLCHAR) == NormalMove) {
2333 // we can capture back with equal piece, so this is no chase but a sacrifice
2334 chaseStack[j] = chaseStack[--chaseStackPointer]; // delete the capture from the chaseStack
2335 j--; /* ! */ continue;
2340 // the attack is on a lower piece, or on a pinned or blocked equal one
2341 CopyBoard(xqCheckers, nullBoard); xqCheckers[EP_STATUS] = 1;
2342 CheckTest(boards[i+1], PosFlags(i+1), -1, -1, -1, -1, FALSE); // if we deliver check with our move, the checkers get marked
2343 // test if the victim is protected by a true protector. First make the capture.
2344 captured = boards[i+1][chaseStack[j].rt][chaseStack[j].ft];
2345 boards[i+1][chaseStack[j].rt][chaseStack[j].ft] = boards[i+1][chaseStack[j].rf][chaseStack[j].ff];
2346 boards[i+1][chaseStack[j].rf][chaseStack[j].ff] = EmptySquare;
2347 // Then test if the opponent can recapture
2348 cl.recaptures = 0; // prepare closure to pass recapture square and count moves to it
2349 cl.rt = chaseStack[j].rt;
2350 cl.ft = chaseStack[j].ft;
2351 if(appData.debugMode) {
2352 fprintf(debugFP, "test if we can recapture %c%c\n", cl.ft+AAA, cl.rt+ONE);
2354 xqCheckers[EP_STATUS] = 2; // causes GenLegal to ignore the checks we delivered with the move, in real life evaded before we captured
2355 GenLegal(boards[i+1], PosFlags(i+1), ProtectedCallback, &cl, EmptySquare); // try all moves
2356 xqCheckers[EP_STATUS] = 0; // disable quasi-legal moves again
2357 // unmake the capture
2358 boards[i+1][chaseStack[j].rf][chaseStack[j].ff] = boards[i+1][chaseStack[j].rt][chaseStack[j].ft];
2359 boards[i+1][chaseStack[j].rt][chaseStack[j].ft] = captured;
2360 // if a recapture was found, piece is protected, and we are not chasing it.
2361 if(cl.recaptures) { // attacked piece was defended by true protector, no chase
2362 chaseStack[j] = chaseStack[--chaseStackPointer]; // so delete from chaseStack
2366 // chaseStack now contains all moves that chased
2367 if(appData.debugMode) { int n;
2368 for(n=0; n<chaseStackPointer; n++)
2369 fprintf(debugFP, "%c%c%c%c ", chaseStack[n].ff+AAA, chaseStack[n].rf+ONE,
2370 chaseStack[n].ft+AAA, chaseStack[n].rt+ONE);
2371 fprintf(debugFP, ": chases\n");
2373 if(i == first) { // copy all people chased by first move of repeat cycle to preyStack
2374 for(j=0; j<chaseStackPointer; j++) {
2375 preyStack[j].rank = chaseStack[j].rt;
2376 preyStack[j].file = chaseStack[j].ft;
2378 preyStackPointer = chaseStackPointer;
2381 for(j=0; j<chaseStackPointer; j++) {
2382 for(k=0; k<preyStackPointer; k++) {
2383 // search the victim of each chase move on the preyStack (first occurrence)
2384 if(chaseStack[j].ft == preyStack[k].file && chaseStack[j].rt == preyStack[k].rank ) {
2385 if(k < tail) break; // piece was already identified as still being chased
2386 preyStack[preyStackPointer] = preyStack[tail]; // move chased piece to bottom part of preyStack
2387 preyStack[tail] = preyStack[k]; // by swapping
2388 preyStack[k] = preyStack[preyStackPointer];
2394 preyStackPointer = tail; // keep bottom part of preyStack, popping pieces unchased on move i.
2395 if(appData.debugMode) { int n;
2396 for(n=0; n<preyStackPointer; n++)
2397 fprintf(debugFP, "%c%c ", preyStack[n].file+AAA, preyStack[n].rank+ONE);
2398 fprintf(debugFP, "always chased upto ply %d\n", i);
2400 // now adjust the location of the chased pieces according to opponent move
2401 for(j=0; j<preyStackPointer; j++) {
2402 if(preyStack[j].rank == moveList[i+1][1]-ONE &&
2403 preyStack[j].file == moveList[i+1][0]-AAA+BOARD_LEFT) {
2404 preyStack[j].rank = moveList[i+1][3]-ONE;
2405 preyStack[j].file = moveList[i+1][2]-AAA+BOARD_LEFT;
2410 return preyStackPointer ? 256*(preyStack[preyStackPointer].file - BOARD_LEFT + AAA) + (preyStack[preyStackPointer].rank + ONE)
2411 : 0; // if any piece was left on preyStack, it has been perpetually chased,and we return the