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 == 'n') jump = 0, desc++;
254 while(*desc == 'j') jump++, desc++;
255 dx = xStep[*p-'A'] - '0'; // step vector of atom
256 dy = yStep[*p-'A'] - '0';
257 if(isdigit(*++p)) expo = atoi(p++); // read exponent
258 if(expo > 9) p++; // allow double-digit
259 desc = p; // this is start of next move
260 if(initial && (board[r][f] != initialPosition[r][f] ||
261 r == 0 && board[TOUCHED_W] & 1<<f ||
262 r == BOARD_HEIGHT-1 && board[TOUCHED_B] & 1<<f ) ) continue;
263 if(expo > 1 && dx == 0 && dy == 0) { // castling indicated by O + number
267 for(dir=0, bit=1; dir<8; dir++, bit += bit) { // loop over directions
268 int i = expo, hop = mode, vx, vy;
269 if(!(bit & dirSet)) continue; // does not move in this direction
270 vx = dx*rot[dir][0] + dy*rot[dir][1]; // rotate step vector
271 vy = dx*rot[dir][2] + dy*rot[dir][3];
272 x = f; y = r; // start square
274 x += vx; y += vy; // step to next square
275 if(y < 0 || y >= BOARD_HEIGHT || x < BOARD_LEFT || x >= BOARD_RGHT) break;
276 if(!jump && board[y - vy + vy/2][x - vx + vx/2] != EmptySquare) break; // blocked
277 if(jump > 1 && board[y - vy + vy/2][x - vx + vx/2] == EmptySquare) break; // no hop
278 if(board[y][x] < BlackPawn) occup = 1; else
279 if(board[y][x] < EmptySquare) occup = 2; else
281 if(hop & 32+64) { if(occup != 4) { if(hop & 64 && i != 1) i = 2; hop &= 31; } continue; } // hopper
282 if(mode & 8 && y == board[EP_RANK] && occup == 4 && board[EP_FILE] == x) { // to e.p. square
283 cb(board, flags, mine == 1 ? WhiteCapturesEnPassant : BlackCapturesEnPassant, r, f, y, x, cl);
285 if(mode & 16) { // castling
286 i = 2; // kludge to elongate move indefinitely
287 if(occup == 4) continue; // skip empty squares
288 if(x == BOARD_LEFT && board[y][x] == initialPosition[y][x]) // reached initial corner piece
289 cb(board, flags, mine == 1 ? WhiteQueenSideCastle : BlackQueenSideCastle, r, f, y, f - expo, cl);
290 if(x == BOARD_RGHT-1 && board[y][x] == initialPosition[y][x])
291 cb(board, flags, mine == 1 ? WhiteKingSideCastle : BlackKingSideCastle, r, f, y, f + expo, cl);
294 if(occup & mode) cb(board, flags, NormalMove, r, f, y, x, cl); // allowed, generate
295 if(occup != 4) break; // not valid transit square
298 dx = dy = 1; dirSet = 0x99; // prepare for diagonal moves of K,Q
299 } while(retry--); // and start doing them
303 // [HGM] move generation now based on hierarchy of subroutines for rays and combinations of rays
306 SlideForward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
311 if (rt >= BOARD_HEIGHT) break;
312 if (SameColor(board[rf][ff], board[rt][ft])) break;
313 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
314 if (board[rt][ft] != EmptySquare) break;
319 SlideBackward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
325 if (SameColor(board[rf][ff], board[rt][ft])) break;
326 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
327 if (board[rt][ft] != EmptySquare) break;
332 SlideVertical (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
334 SlideForward(board, flags, rf, ff, callback, closure);
335 SlideBackward(board, flags, rf, ff, callback, closure);
339 SlideSideways (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
341 int i, s, rt = rf, ft;
342 for(s = -1; s <= 1; s+= 2) {
345 if (ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
346 if (SameColor(board[rf][ff], board[rt][ft])) break;
347 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
348 if (board[rt][ft] != EmptySquare) break;
354 SlideDiagForward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
357 for(s = -1; s <= 1; s+= 2) {
361 if (rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
362 if (SameColor(board[rf][ff], board[rt][ft])) break;
363 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
364 if (board[rt][ft] != EmptySquare) break;
370 SlideDiagBackward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
373 for(s = -1; s <= 1; s+= 2) {
377 if (rt < 0 || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
378 if (SameColor(board[rf][ff], board[rt][ft])) break;
379 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
380 if (board[rt][ft] != EmptySquare) break;
386 Rook (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
388 SlideVertical(board, flags, rf, ff, callback, closure);
389 SlideSideways(board, flags, rf, ff, callback, closure);
393 Bishop (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
395 SlideDiagForward(board, flags, rf, ff, callback, closure);
396 SlideDiagBackward(board, flags, rf, ff, callback, closure);
400 Sting (Board board, int flags, int rf, int ff, int dy, int dx, MoveCallback callback, VOIDSTAR closure)
401 { // Lion-like move of Horned Falcon and Souring Eagle
402 int ft = ff + dx, rt = rf + dy;
403 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) return;
404 if (!SameColor(board[rf][ff], board[rt][ft]))
405 callback(board, flags, board[rt][ft] != EmptySquare ? FirstLeg : NormalMove, rf, ff, rt, ft, closure);
407 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) return;
408 if (!SameColor(board[rf][ff], board[rt][ft]))
409 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
413 StepForward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
415 int ft = ff, rt = rf + 1;
416 if (rt >= BOARD_HEIGHT) return;
417 if (SameColor(board[rf][ff], board[rt][ft])) return;
418 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
422 StepBackward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
424 int ft = ff, rt = rf - 1;
426 if (SameColor(board[rf][ff], board[rt][ft])) return;
427 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
431 StepSideways (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
435 if (!(rt >= BOARD_HEIGHT || ft >= BOARD_RGHT) && !SameColor(board[rf][ff], board[rt][ft]))
436 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
438 if (!(rt >= BOARD_HEIGHT || ft < BOARD_LEFT) && !SameColor(board[rf][ff], board[rt][ft]))
439 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
443 StepDiagForward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
446 if (rt >= BOARD_HEIGHT) return;
448 if (!(rt >= BOARD_HEIGHT || ft >= BOARD_RGHT) && !SameColor(board[rf][ff], board[rt][ft]))
449 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
451 if (!(rt >= BOARD_HEIGHT || ft < BOARD_LEFT) && !SameColor(board[rf][ff], board[rt][ft]))
452 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
456 StepDiagBackward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
461 if (!(rt < 0 || ft >= BOARD_RGHT) && !SameColor(board[rf][ff], board[rt][ft]))
462 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
464 if (!(rt < 0 || ft < BOARD_LEFT) && !SameColor(board[rf][ff], board[rt][ft]))
465 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
469 StepVertical (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
471 StepForward(board, flags, rf, ff, callback, closure);
472 StepBackward(board, flags, rf, ff, callback, closure);
476 Ferz (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
478 StepDiagForward(board, flags, rf, ff, callback, closure);
479 StepDiagBackward(board, flags, rf, ff, callback, closure);
483 Wazir (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
485 StepVertical(board, flags, rf, ff, callback, closure);
486 StepSideways(board, flags, rf, ff, callback, closure);
490 Knight (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
493 for (i = -1; i <= 1; i += 2)
494 for (j = -1; j <= 1; j += 2)
495 for (s = 1; s <= 2; s++) {
498 if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
499 && ( gameInfo.variant != VariantXiangqi || board[rf+i*(s-1)][ff+j*(2-s)] == EmptySquare)
500 && !SameColor(board[rf][ff], board[rt][ft]))
501 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
505 /* Call callback once for each pseudo-legal move in the given
506 position, except castling moves. A move is pseudo-legal if it is
507 legal, or if it would be legal except that it leaves the king in
508 check. In the arguments, epfile is EP_NONE if the previous move
509 was not a double pawn push, or the file 0..7 if it was, or
510 EP_UNKNOWN if we don't know and want to allow all e.p. captures.
511 Promotion moves generated are to Queen only.
514 GenPseudoLegal (Board board, int flags, MoveCallback callback, VOIDSTAR closure, ChessSquare filter)
515 // speed: only do moves with this piece type
518 int i, j, d, s, fs, rs, rt, ft, m;
519 int epfile = (signed char)board[EP_STATUS]; // [HGM] gamestate: extract ep status from board
520 int promoRank = gameInfo.variant == VariantMakruk || gameInfo.variant == VariantGrand || gameInfo.variant == VariantChuChess ? 3 : 1;
522 for (rf = 0; rf < BOARD_HEIGHT; rf++)
523 for (ff = BOARD_LEFT; ff < BOARD_RGHT; ff++) {
526 if(board[rf][ff] == EmptySquare) continue;
527 if ((flags & F_WHITE_ON_MOVE) != (board[rf][ff] < BlackPawn)) continue; // [HGM] speed: wrong color
528 m = 0; piece = board[rf][ff];
529 if(PieceToChar(piece) == '~')
530 piece = (ChessSquare) ( DEMOTED piece );
531 if(filter != EmptySquare && piece != filter) continue;
532 if(pieceDesc[piece]) { MovesFromString(board, flags, ff, rf, pieceDesc[piece], callback, closure); continue; } // [HGM] gen
533 if(IS_SHOGI(gameInfo.variant))
534 piece = (ChessSquare) ( SHOGI piece );
536 switch ((int)piece) {
537 /* case EmptySquare: [HGM] this is nonsense, and conflicts with Shogi cases */
539 /* can't happen ([HGM] except for faries...) */
543 if(gameInfo.variant == VariantXiangqi) {
544 /* [HGM] capture and move straight ahead in Xiangqi */
545 if (rf < BOARD_HEIGHT-1 &&
546 !SameColor(board[rf][ff], board[rf + 1][ff]) ) {
547 callback(board, flags, NormalMove,
548 rf, ff, rf + 1, ff, closure);
550 /* and move sideways when across the river */
551 for (s = -1; s <= 1; s += 2) {
552 if (rf >= BOARD_HEIGHT>>1 &&
553 ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
554 !WhitePiece(board[rf][ff+s]) ) {
555 callback(board, flags, NormalMove,
556 rf, ff, rf, ff+s, closure);
561 if (rf < BOARD_HEIGHT-1 && board[rf + 1][ff] == EmptySquare) {
562 callback(board, flags,
563 rf >= BOARD_HEIGHT-1-promoRank ? WhitePromotion : NormalMove,
564 rf, ff, rf + 1, ff, closure);
566 if (rf <= (BOARD_HEIGHT>>1)-3 && board[rf+1][ff] == EmptySquare && // [HGM] grand: also on 3rd rank on 10-board
567 gameInfo.variant != VariantShatranj && /* [HGM] */
568 gameInfo.variant != VariantCourier && /* [HGM] */
569 board[rf+2][ff] == EmptySquare ) {
570 callback(board, flags, NormalMove,
571 rf, ff, rf+2, ff, closure);
573 for (s = -1; s <= 1; s += 2) {
574 if (rf < BOARD_HEIGHT-1 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
575 ((flags & F_KRIEGSPIEL_CAPTURE) ||
576 BlackPiece(board[rf + 1][ff + s]))) {
577 callback(board, flags,
578 rf >= BOARD_HEIGHT-1-promoRank ? WhitePromotion : NormalMove,
579 rf, ff, rf + 1, ff + s, closure);
581 if (rf >= BOARD_HEIGHT+1>>1) {// [HGM] grand: 4th & 5th rank on 10-board
582 if (ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
583 (epfile == ff + s || epfile == EP_UNKNOWN) && rf < BOARD_HEIGHT-3 &&
584 board[rf][ff + s] == BlackPawn &&
585 board[rf+1][ff + s] == EmptySquare) {
586 callback(board, flags, WhiteCapturesEnPassant,
587 rf, ff, rf+1, ff + s, closure);
594 if(gameInfo.variant == VariantXiangqi) {
595 /* [HGM] capture straight ahead in Xiangqi */
596 if (rf > 0 && !SameColor(board[rf][ff], board[rf - 1][ff]) ) {
597 callback(board, flags, NormalMove,
598 rf, ff, rf - 1, ff, closure);
600 /* and move sideways when across the river */
601 for (s = -1; s <= 1; s += 2) {
602 if (rf < BOARD_HEIGHT>>1 &&
603 ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
604 !BlackPiece(board[rf][ff+s]) ) {
605 callback(board, flags, NormalMove,
606 rf, ff, rf, ff+s, closure);
611 if (rf > 0 && board[rf - 1][ff] == EmptySquare) {
612 callback(board, flags,
613 rf <= promoRank ? BlackPromotion : NormalMove,
614 rf, ff, rf - 1, ff, closure);
616 if (rf >= (BOARD_HEIGHT+1>>1)+2 && board[rf-1][ff] == EmptySquare && // [HGM] grand
617 gameInfo.variant != VariantShatranj && /* [HGM] */
618 gameInfo.variant != VariantCourier && /* [HGM] */
619 board[rf-2][ff] == EmptySquare) {
620 callback(board, flags, NormalMove,
621 rf, ff, rf-2, ff, closure);
623 for (s = -1; s <= 1; s += 2) {
624 if (rf > 0 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
625 ((flags & F_KRIEGSPIEL_CAPTURE) ||
626 WhitePiece(board[rf - 1][ff + s]))) {
627 callback(board, flags,
628 rf <= promoRank ? BlackPromotion : NormalMove,
629 rf, ff, rf - 1, ff + s, closure);
631 if (rf < BOARD_HEIGHT>>1) {
632 if (ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
633 (epfile == ff + s || epfile == EP_UNKNOWN) && rf > 2 &&
634 board[rf][ff + s] == WhitePawn &&
635 board[rf-1][ff + s] == EmptySquare) {
636 callback(board, flags, BlackCapturesEnPassant,
637 rf, ff, rf-1, ff + s, closure);
647 for (i = -1; i <= 1; i += 2)
648 for (j = -1; j <= 1; j += 2)
649 for (s = 1; s <= 2; s++) {
652 if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
653 && ( gameInfo.variant != VariantXiangqi || board[rf+i*(s-1)][ff+j*(2-s)] == EmptySquare)
654 && !SameColor(board[rf][ff], board[rt][ft]))
655 callback(board, flags, NormalMove,
656 rf, ff, rt, ft, closure);
660 case SHOGI WhiteKnight:
661 for (s = -1; s <= 1; s += 2) {
662 if (rf < BOARD_HEIGHT-2 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
663 !SameColor(board[rf][ff], board[rf + 2][ff + s])) {
664 callback(board, flags, NormalMove,
665 rf, ff, rf + 2, ff + s, closure);
670 case SHOGI BlackKnight:
671 for (s = -1; s <= 1; s += 2) {
672 if (rf > 1 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
673 !SameColor(board[rf][ff], board[rf - 2][ff + s])) {
674 callback(board, flags, NormalMove,
675 rf, ff, rf - 2, ff + s, closure);
682 for (d = 0; d <= 1; d++)
683 for (s = -1; s <= 1; s += 2) {
686 rt = rf + (i * s) * d;
687 ft = ff + (i * s) * (1 - d);
688 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
689 if (m == 0 && board[rt][ft] == EmptySquare)
690 callback(board, flags, NormalMove,
691 rf, ff, rt, ft, closure);
692 if (m == 1 && board[rt][ft] != EmptySquare &&
693 !SameColor(board[rf][ff], board[rt][ft]) )
694 callback(board, flags, NormalMove,
695 rf, ff, rt, ft, closure);
696 if (board[rt][ft] != EmptySquare && m++) break;
701 /* Gold General (and all its promoted versions) . First do the */
702 /* diagonal forward steps, then proceed as normal Wazir */
703 case SHOGI (PROMOTED WhitePawn):
704 if(gameInfo.variant == VariantShogi) goto WhiteGold;
705 case SHOGI (PROMOTED BlackPawn):
706 if(gameInfo.variant == VariantShogi) goto BlackGold;
707 SlideVertical(board, flags, rf, ff, callback, closure);
710 case SHOGI (PROMOTED WhiteKnight):
711 if(gameInfo.variant == VariantShogi) goto WhiteGold;
712 case SHOGI BlackDrunk:
713 case SHOGI BlackAlfil:
714 Ferz(board, flags, rf, ff, callback, closure);
715 StepSideways(board, flags, rf, ff, callback, closure);
716 StepBackward(board, flags, rf, ff, callback, closure);
719 case SHOGI (PROMOTED BlackKnight):
720 if(gameInfo.variant == VariantShogi) goto BlackGold;
721 case SHOGI WhiteDrunk:
722 case SHOGI WhiteAlfil:
723 Ferz(board, flags, rf, ff, callback, closure);
724 StepSideways(board, flags, rf, ff, callback, closure);
725 StepForward(board, flags, rf, ff, callback, closure);
729 case SHOGI WhiteStag:
730 case SHOGI BlackStag:
731 if(gameInfo.variant == VariantShogi) goto BlackGold;
732 SlideVertical(board, flags, rf, ff, callback, closure);
733 Ferz(board, flags, rf, ff, callback, closure);
734 StepSideways(board, flags, rf, ff, callback, closure);
737 case SHOGI (PROMOTED WhiteQueen):
738 case SHOGI WhiteTokin:
739 case SHOGI WhiteWazir:
741 StepDiagForward(board, flags, rf, ff, callback, closure);
742 Wazir(board, flags, rf, ff, callback, closure);
745 case SHOGI (PROMOTED BlackQueen):
746 case SHOGI BlackTokin:
747 case SHOGI BlackWazir:
749 StepDiagBackward(board, flags, rf, ff, callback, closure);
750 Wazir(board, flags, rf, ff, callback, closure);
755 Wazir(board, flags, rf, ff, callback, closure);
758 case SHOGI WhiteMarshall:
759 case SHOGI BlackMarshall:
760 Ferz(board, flags, rf, ff, callback, closure);
761 for (d = 0; d <= 1; d++)
762 for (s = -2; s <= 2; s += 4) {
764 ft = ff + s * (1 - d);
765 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) continue;
766 if (!SameColor(board[rf][ff], board[rt][ft]) )
767 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
771 case SHOGI WhiteAngel:
772 case SHOGI BlackAngel:
773 Wazir(board, flags, rf, ff, callback, closure);
777 /* [HGM] support Shatranj pieces */
778 for (rs = -1; rs <= 1; rs += 2)
779 for (fs = -1; fs <= 1; fs += 2) {
782 if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
783 && ( gameInfo.variant != VariantXiangqi ||
784 board[rf+rs][ff+fs] == EmptySquare && (2*rf < BOARD_HEIGHT) == (2*rt < BOARD_HEIGHT) )
786 && !SameColor(board[rf][ff], board[rt][ft]))
787 callback(board, flags, NormalMove,
788 rf, ff, rt, ft, closure);
789 if(gameInfo.variant == VariantShatranj || gameInfo.variant == VariantCourier ||
790 gameInfo.variant == VariantChu || gameInfo.variant == VariantXiangqi) continue; // classical Alfil
791 rt = rf + rs; // in unknown variant we assume Modern Elephant, which can also do one step
793 if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
794 && !SameColor(board[rf][ff], board[rt][ft]))
795 callback(board, flags, NormalMove,
796 rf, ff, rt, ft, closure);
798 if(gameInfo.variant == VariantSpartan)
799 for(fs = -1; fs <= 1; fs += 2) {
801 if (!(ft < BOARD_LEFT || ft >= BOARD_RGHT) && board[rf][ft] == EmptySquare)
802 callback(board, flags, NormalMove, rf, ff, rf, ft, closure);
806 /* Make Dragon-Horse also do Dababba moves outside Shogi, for better disambiguation in variant Fairy */
809 if(gameInfo.variant == VariantChuChess) goto DragonHorse;
810 for (d = 0; d <= 1; d++) // Dababba moves that Rook cannot do
811 for (s = -2; s <= 2; s += 4) {
813 ft = ff + s * (1 - d);
814 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) continue;
815 if (SameColor(board[rf][ff], board[rt][ft])) continue;
816 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
819 /* Shogi Dragon Horse has to continue with Wazir after Bishop */
820 case SHOGI WhiteCardinal:
821 case SHOGI BlackCardinal:
822 case SHOGI WhitePCardinal:
823 case SHOGI BlackPCardinal:
825 Bishop(board, flags, rf, ff, callback, closure);
826 Wazir(board, flags, rf, ff, callback, closure);
829 /* Capablanca Archbishop continues as Knight */
832 Knight(board, flags, rf, ff, callback, closure);
834 /* Shogi Bishops are ordinary Bishops */
835 case SHOGI WhiteBishop:
836 case SHOGI BlackBishop:
837 case SHOGI WhitePBishop:
838 case SHOGI BlackPBishop:
841 Bishop(board, flags, rf, ff, callback, closure);
844 /* Shogi Lance is unlike anything, and asymmetric at that */
845 case SHOGI WhiteQueen:
846 if(gameInfo.variant == VariantChu) goto doQueen;
850 if (rt >= BOARD_HEIGHT) break;
851 if (SameColor(board[rf][ff], board[rt][ft])) break;
852 callback(board, flags, NormalMove,
853 rf, ff, rt, ft, closure);
854 if (board[rt][ft] != EmptySquare) break;
858 case SHOGI BlackQueen:
859 if(gameInfo.variant == VariantChu) goto doQueen;
864 if (SameColor(board[rf][ff], board[rt][ft])) break;
865 callback(board, flags, NormalMove,
866 rf, ff, rt, ft, closure);
867 if (board[rt][ft] != EmptySquare) break;
871 /* Make Dragon-King Dababba & Rook-like outside Shogi, for better disambiguation in variant Fairy */
874 if(gameInfo.variant == VariantChuChess) goto DragonKing;
875 for (d = 0; d <= 1; d++) // Dababba moves that Rook cannot do
876 for (s = -2; s <= 2; s += 4) {
878 ft = ff + s * (1 - d);
879 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) continue;
880 if (board[rf+rt>>1][ff+ft>>1] == EmptySquare && gameInfo.variant != VariantSpartan) continue;
881 if (SameColor(board[rf][ff], board[rt][ft])) continue;
882 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
884 if(gameInfo.variant == VariantSpartan) // in Spartan Chess restrict range to modern Dababba
885 Wazir(board, flags, rf, ff, callback, closure);
887 Rook(board, flags, rf, ff, callback, closure);
890 /* Shogi Dragon King has to continue as Ferz after Rook moves */
891 case SHOGI WhiteDragon:
892 case SHOGI BlackDragon:
893 case SHOGI WhitePDragon:
894 case SHOGI BlackPDragon:
896 Rook(board, flags, rf, ff, callback, closure);
897 Ferz(board, flags, rf, ff, callback, closure);
901 /* Capablanca Chancellor sets flag to continue as Knight */
904 Rook(board, flags, rf, ff, callback, closure);
905 if(gameInfo.variant == VariantSpartan) // in Spartan Chess Chancellor is used for Dragon King.
906 Ferz(board, flags, rf, ff, callback, closure);
908 Knight(board, flags, rf, ff, callback, closure);
911 /* Shogi Rooks are ordinary Rooks */
912 case SHOGI WhiteRook:
913 case SHOGI BlackRook:
914 case SHOGI WhitePRook:
915 case SHOGI BlackPRook:
918 Rook(board, flags, rf, ff, callback, closure);
923 case SHOGI WhiteMother:
924 case SHOGI BlackMother:
926 Rook(board, flags, rf, ff, callback, closure);
927 Bishop(board, flags, rf, ff, callback, closure);
930 case SHOGI WhitePawn:
931 StepForward(board, flags, rf, ff, callback, closure);
934 case SHOGI BlackPawn:
935 StepBackward(board, flags, rf, ff, callback, closure);
939 if(gameInfo.variant != VariantMakruk && gameInfo.variant != VariantASEAN) goto commoner;
940 case SHOGI WhiteFerz:
941 Ferz(board, flags, rf, ff, callback, closure);
942 StepForward(board, flags, rf, ff, callback, closure);
946 if(gameInfo.variant != VariantMakruk && gameInfo.variant != VariantASEAN) goto commoner;
947 case SHOGI BlackFerz:
948 StepBackward(board, flags, rf, ff, callback, closure);
952 /* [HGM] support Shatranj pieces */
953 Ferz(board, flags, rf, ff, callback, closure);
958 Knight(board, flags, rf, ff, callback, closure); // [HGM] superchess: use for Centaur
961 case SHOGI WhiteMonarch:
962 case SHOGI BlackMonarch:
963 case SHOGI WhiteKing:
964 case SHOGI BlackKing:
967 Ferz(board, flags, rf, ff, callback, closure);
968 Wazir(board, flags, rf, ff, callback, closure);
971 case WhiteNightrider:
972 case BlackNightrider:
973 for (i = -1; i <= 1; i += 2)
974 for (j = -1; j <= 1; j += 2)
975 for (s = 1; s <= 2; s++) { int k;
979 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
980 if (SameColor(board[rf][ff], board[rt][ft])) break;
981 callback(board, flags, NormalMove,
982 rf, ff, rt, ft, closure);
983 if (board[rt][ft] != EmptySquare) break;
989 Bishop(board, flags, rf, ff, callback, closure);
990 Rook(board, flags, rf, ff, callback, closure);
991 Knight(board, flags, rf, ff, callback, closure);
994 // Use Lance as Berolina / Spartan Pawn.
996 if(gameInfo.variant == VariantSuper) goto Amazon;
997 if (rf < BOARD_HEIGHT-1 && BlackPiece(board[rf + 1][ff]))
998 callback(board, flags,
999 rf >= BOARD_HEIGHT-1-promoRank ? WhitePromotion : NormalMove,
1000 rf, ff, rf + 1, ff, closure);
1001 for (s = -1; s <= 1; s += 2) {
1002 if (rf < BOARD_HEIGHT-1 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT && board[rf + 1][ff + s] == EmptySquare)
1003 callback(board, flags,
1004 rf >= BOARD_HEIGHT-1-promoRank ? WhitePromotion : NormalMove,
1005 rf, ff, rf + 1, ff + s, closure);
1006 if (rf == 1 && ff + 2*s >= BOARD_LEFT && ff + 2*s < BOARD_RGHT && board[3][ff + 2*s] == EmptySquare )
1007 callback(board, flags, NormalMove, rf, ff, 3, ff + 2*s, closure);
1012 if(gameInfo.variant == VariantSuper) goto Amazon;
1013 if (rf > 0 && WhitePiece(board[rf - 1][ff]))
1014 callback(board, flags,
1015 rf <= promoRank ? BlackPromotion : NormalMove,
1016 rf, ff, rf - 1, ff, closure);
1017 for (s = -1; s <= 1; s += 2) {
1018 if (rf > 0 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT && board[rf - 1][ff + s] == EmptySquare)
1019 callback(board, flags,
1020 rf <= promoRank ? BlackPromotion : NormalMove,
1021 rf, ff, rf - 1, ff + s, closure);
1022 if (rf == BOARD_HEIGHT-2 && ff + 2*s >= BOARD_LEFT && ff + 2*s < BOARD_RGHT && board[rf-2][ff + 2*s] == EmptySquare )
1023 callback(board, flags, NormalMove, rf, ff, rf-2, ff + 2*s, closure);
1027 case SHOGI WhiteNothing:
1028 case SHOGI BlackNothing:
1029 case SHOGI WhiteLion:
1030 case SHOGI BlackLion:
1033 for(rt = rf - 2; rt <= rf + 2; rt++) for(ft = ff - 2; ft <= ff + 2; ft++) {
1034 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) continue;
1035 if (!(ff == ft && rf == rt) && SameColor(board[rf][ff], board[rt][ft])) continue;
1036 callback(board, flags, (rt-rf)*(rt-rf) + (ff-ft)*(ff-ft) < 3 && board[rt][ft] != EmptySquare ? FirstLeg : NormalMove,
1037 rf, ff, rt, ft, closure);
1041 case SHOGI WhiteFalcon:
1042 case SHOGI BlackFalcon:
1043 case SHOGI WhitePDagger:
1044 case SHOGI BlackPDagger:
1045 SlideSideways(board, flags, rf, ff, callback, closure);
1046 StepVertical(board, flags, rf, ff, callback, closure);
1049 case SHOGI WhiteCobra:
1050 case SHOGI BlackCobra:
1051 StepVertical(board, flags, rf, ff, callback, closure);
1054 case SHOGI (PROMOTED WhiteFerz):
1055 if(gameInfo.variant == VariantShogi) goto WhiteGold;
1056 case SHOGI (PROMOTED BlackFerz):
1057 if(gameInfo.variant == VariantShogi) goto BlackGold;
1058 case SHOGI WhitePSword:
1059 case SHOGI BlackPSword:
1060 SlideVertical(board, flags, rf, ff, callback, closure);
1061 StepSideways(board, flags, rf, ff, callback, closure);
1064 case SHOGI WhiteUnicorn:
1065 case SHOGI BlackUnicorn:
1066 Ferz(board, flags, rf, ff, callback, closure);
1067 StepVertical(board, flags, rf, ff, callback, closure);
1070 case SHOGI WhiteMan:
1071 StepDiagForward(board, flags, rf, ff, callback, closure);
1072 StepVertical(board, flags, rf, ff, callback, closure);
1075 case SHOGI BlackMan:
1076 StepDiagBackward(board, flags, rf, ff, callback, closure);
1077 StepVertical(board, flags, rf, ff, callback, closure);
1080 case SHOGI WhiteHCrown:
1081 case SHOGI BlackHCrown:
1082 Bishop(board, flags, rf, ff, callback, closure);
1083 SlideSideways(board, flags, rf, ff, callback, closure);
1086 case SHOGI WhiteCrown:
1087 case SHOGI BlackCrown:
1088 Bishop(board, flags, rf, ff, callback, closure);
1089 SlideVertical(board, flags, rf, ff, callback, closure);
1092 case SHOGI WhiteHorned:
1093 Sting(board, flags, rf, ff, 1, 0, callback, closure);
1094 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1095 if(killX >= 0) break;
1096 Bishop(board, flags, rf, ff, callback, closure);
1097 SlideSideways(board, flags, rf, ff, callback, closure);
1098 SlideBackward(board, flags, rf, ff, callback, closure);
1101 case SHOGI BlackHorned:
1102 Sting(board, flags, rf, ff, -1, 0, callback, closure);
1103 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1104 if(killX >= 0) break;
1105 Bishop(board, flags, rf, ff, callback, closure);
1106 SlideSideways(board, flags, rf, ff, callback, closure);
1107 SlideForward(board, flags, rf, ff, callback, closure);
1110 case SHOGI WhiteEagle:
1111 Sting(board, flags, rf, ff, 1, 1, callback, closure);
1112 Sting(board, flags, rf, ff, 1, -1, callback, closure);
1113 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1114 if(killX >= 0) break;
1115 Rook(board, flags, rf, ff, callback, closure);
1116 SlideDiagBackward(board, flags, rf, ff, callback, closure);
1119 case SHOGI BlackEagle:
1120 Sting(board, flags, rf, ff, -1, 1, callback, closure);
1121 Sting(board, flags, rf, ff, -1, -1, callback, closure);
1122 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1123 if(killX >= 0) break;
1124 Rook(board, flags, rf, ff, callback, closure);
1125 SlideDiagForward(board, flags, rf, ff, callback, closure);
1128 case SHOGI WhiteDolphin:
1129 case SHOGI BlackHorse:
1130 SlideDiagBackward(board, flags, rf, ff, callback, closure);
1131 SlideVertical(board, flags, rf, ff, callback, closure);
1134 case SHOGI BlackDolphin:
1135 case SHOGI WhiteHorse:
1136 SlideDiagForward(board, flags, rf, ff, callback, closure);
1137 SlideVertical(board, flags, rf, ff, callback, closure);
1140 case SHOGI WhiteLance:
1141 SlideForward(board, flags, rf, ff, callback, closure);
1144 case SHOGI BlackLance:
1145 SlideBackward(board, flags, rf, ff, callback, closure);
1148 case WhiteFalcon: // [HGM] wild: for wildcards, self-capture symbolizes move to anywhere
1152 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1165 int rFilter, fFilter; // [HGM] speed: sorry, but I get a bit tired of this closure madness
1166 Board xqCheckers, nullBoard;
1168 extern void GenLegalCallback P((Board board, int flags, ChessMove kind,
1169 int rf, int ff, int rt, int ft,
1173 GenLegalCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1175 register GenLegalClosure *cl = (GenLegalClosure *) closure;
1177 if(rFilter >= 0 && rFilter != rt || fFilter >= 0 && fFilter != ft) return; // [HGM] speed: ignore moves with wrong to-square
1179 if (board[EP_STATUS] == EP_IRON_LION && (board[rt][ft] == WhiteLion || board[rt][ft] == BlackLion)) return; //[HGM] lion
1181 if (!(flags & F_IGNORE_CHECK) ) {
1182 int check, promo = (gameInfo.variant == VariantSpartan && kind == BlackPromotion);
1185 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++)
1186 kings += (board[r][f] == BlackKing);
1190 board[rf][ff] = BlackKing; // [HGM] spartan: promote to King before check-test
1192 check = CheckTest(board, flags, rf, ff, rt, ft,
1193 kind == WhiteCapturesEnPassant ||
1194 kind == BlackCapturesEnPassant);
1195 if(promo) board[rf][ff] = BlackLance;
1198 if (flags & F_ATOMIC_CAPTURE) {
1199 if (board[rt][ft] != EmptySquare ||
1200 kind == WhiteCapturesEnPassant || kind == BlackCapturesEnPassant) {
1202 ChessSquare king = (flags & F_WHITE_ON_MOVE) ? WhiteKing : BlackKing;
1203 if (board[rf][ff] == king) return;
1204 for (r = rt-1; r <= rt+1; r++) {
1205 for (f = ft-1; f <= ft+1; f++) {
1206 if (r >= 0 && r < BOARD_HEIGHT && f >= BOARD_LEFT && f < BOARD_RGHT &&
1207 board[r][f] == king) return;
1212 cl->cb(board, flags, kind, rf, ff, rt, ft, cl->cl);
1219 int captures; // [HGM] losers
1220 } LegalityTestClosure;
1223 /* Like GenPseudoLegal, but (1) include castling moves, (2) unless
1224 F_IGNORE_CHECK is set in the flags, omit moves that would leave the
1225 king in check, and (3) if F_ATOMIC_CAPTURE is set in the flags, omit
1226 moves that would destroy your own king. The CASTLE_OK flags are
1227 true if castling is not yet ruled out by a move of the king or
1228 rook. Return TRUE if the player on move is currently in check and
1229 F_IGNORE_CHECK is not set. [HGM] add castlingRights parameter */
1231 GenLegal (Board board, int flags, MoveCallback callback, VOIDSTAR closure, ChessSquare filter)
1234 int ff, ft, k, left, right, swap;
1235 int ignoreCheck = (flags & F_IGNORE_CHECK) != 0;
1236 ChessSquare wKing = WhiteKing, bKing = BlackKing, *castlingRights = board[CASTLING];
1237 int inCheck = !ignoreCheck && CheckTest(board, flags, -1, -1, -1, -1, FALSE); // kludge alert: this would mark pre-existing checkers if status==1
1242 xqCheckers[EP_STATUS] *= 2; // quasi: if previous CheckTest has been marking, we now set flag for suspending same checkers
1243 if(filter == EmptySquare) rFilter = fFilter = -1; // [HGM] speed: do not filter on square if we do not filter on piece
1244 GenPseudoLegal(board, flags, GenLegalCallback, (VOIDSTAR) &cl, filter);
1246 if (inCheck) return TRUE;
1248 /* Generate castling moves */
1249 if(gameInfo.variant == VariantKnightmate) { /* [HGM] Knightmate */
1250 wKing = WhiteUnicorn; bKing = BlackUnicorn;
1253 p = (flags & F_WHITE_ON_MOVE ? pieceDesc[wKing] : pieceDesc[bKing]);
1254 if(p && strchr(p, 'O')) return FALSE; // [HGM] gen: castlings were already generated from string
1256 for (ff = BOARD_WIDTH>>1; ff >= (BOARD_WIDTH-1)>>1; ff-- /*ics wild 1*/) {
1257 if ((flags & F_WHITE_ON_MOVE) &&
1258 (flags & F_WHITE_KCASTLE_OK) &&
1259 board[0][ff] == wKing &&
1260 board[0][ff + 1] == EmptySquare &&
1261 board[0][ff + 2] == EmptySquare &&
1262 board[0][BOARD_RGHT-3] == EmptySquare &&
1263 board[0][BOARD_RGHT-2] == EmptySquare &&
1264 board[0][BOARD_RGHT-1] == WhiteRook &&
1265 castlingRights[0] != NoRights && /* [HGM] check rights */
1266 ( castlingRights[2] == ff || castlingRights[6] == ff ) &&
1268 (!CheckTest(board, flags, 0, ff, 0, ff + 1, FALSE) &&
1269 !CheckTest(board, flags, 0, ff, 0, BOARD_RGHT-3, FALSE) &&
1270 (gameInfo.variant != VariantJanus || !CheckTest(board, flags, 0, ff, 0, BOARD_RGHT-2, FALSE)) &&
1271 !CheckTest(board, flags, 0, ff, 0, ff + 2, FALSE)))) {
1273 callback(board, flags,
1274 ff==BOARD_WIDTH>>1 ? WhiteKingSideCastle : WhiteKingSideCastleWild,
1275 0, ff, 0, ff + ((gameInfo.boardWidth+2)>>2) + (gameInfo.variant == VariantJanus), closure);
1277 if ((flags & F_WHITE_ON_MOVE) &&
1278 (flags & F_WHITE_QCASTLE_OK) &&
1279 board[0][ff] == wKing &&
1280 board[0][ff - 1] == EmptySquare &&
1281 board[0][ff - 2] == EmptySquare &&
1282 board[0][BOARD_LEFT+2] == EmptySquare &&
1283 board[0][BOARD_LEFT+1] == EmptySquare &&
1284 board[0][BOARD_LEFT+0] == WhiteRook &&
1285 castlingRights[1] != NoRights && /* [HGM] check rights */
1286 ( castlingRights[2] == ff || castlingRights[6] == ff ) &&
1288 (!CheckTest(board, flags, 0, ff, 0, ff - 1, FALSE) &&
1289 !CheckTest(board, flags, 0, ff, 0, BOARD_LEFT+3, FALSE) &&
1290 !CheckTest(board, flags, 0, ff, 0, ff - 2, FALSE)))) {
1292 callback(board, flags,
1293 ff==BOARD_WIDTH>>1 ? WhiteQueenSideCastle : WhiteQueenSideCastleWild,
1294 0, ff, 0, ff - ((gameInfo.boardWidth+2)>>2), closure);
1296 if (!(flags & F_WHITE_ON_MOVE) &&
1297 (flags & F_BLACK_KCASTLE_OK) &&
1298 board[BOARD_HEIGHT-1][ff] == bKing &&
1299 board[BOARD_HEIGHT-1][ff + 1] == EmptySquare &&
1300 board[BOARD_HEIGHT-1][ff + 2] == EmptySquare &&
1301 board[BOARD_HEIGHT-1][BOARD_RGHT-3] == EmptySquare &&
1302 board[BOARD_HEIGHT-1][BOARD_RGHT-2] == EmptySquare &&
1303 board[BOARD_HEIGHT-1][BOARD_RGHT-1] == BlackRook &&
1304 castlingRights[3] != NoRights && /* [HGM] check rights */
1305 ( castlingRights[5] == ff || castlingRights[7] == ff ) &&
1307 (!CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff + 1, FALSE) &&
1308 !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, BOARD_RGHT-3, FALSE) &&
1309 (gameInfo.variant != VariantJanus || !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, BOARD_RGHT-2, FALSE)) &&
1310 !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff + 2, FALSE)))) {
1312 callback(board, flags,
1313 ff==BOARD_WIDTH>>1 ? BlackKingSideCastle : BlackKingSideCastleWild,
1314 BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff + ((gameInfo.boardWidth+2)>>2) + (gameInfo.variant == VariantJanus), closure);
1316 if (!(flags & F_WHITE_ON_MOVE) &&
1317 (flags & F_BLACK_QCASTLE_OK) &&
1318 board[BOARD_HEIGHT-1][ff] == bKing &&
1319 board[BOARD_HEIGHT-1][ff - 1] == EmptySquare &&
1320 board[BOARD_HEIGHT-1][ff - 2] == EmptySquare &&
1321 board[BOARD_HEIGHT-1][BOARD_LEFT+2] == EmptySquare &&
1322 board[BOARD_HEIGHT-1][BOARD_LEFT+1] == EmptySquare &&
1323 board[BOARD_HEIGHT-1][BOARD_LEFT+0] == BlackRook &&
1324 castlingRights[4] != NoRights && /* [HGM] check rights */
1325 ( castlingRights[5] == ff || castlingRights[7] == ff ) &&
1327 (!CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff - 1, FALSE) &&
1328 !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, BOARD_LEFT+3, FALSE) &&
1329 !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff - 2, FALSE)))) {
1331 callback(board, flags,
1332 ff==BOARD_WIDTH>>1 ? BlackQueenSideCastle : BlackQueenSideCastleWild,
1333 BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff - ((gameInfo.boardWidth+2)>>2), closure);
1337 if((swap = gameInfo.variant == VariantSChess) || flags & F_FRC_TYPE_CASTLING) {
1339 /* generate all potential FRC castling moves (KxR), ignoring flags */
1340 /* [HGM] test if the Rooks we find have castling rights */
1341 /* In S-Chess we generate RxK for allowed castlings, for gating at Rook square */
1344 if ((flags & F_WHITE_ON_MOVE) != 0) {
1345 ff = castlingRights[2]; /* King file if we have any rights */
1346 if(ff != NoRights && board[0][ff] == WhiteKing) {
1347 if (appData.debugMode) {
1348 fprintf(debugFP, "FRC castling, %d %d %d %d %d %d\n",
1349 castlingRights[0],castlingRights[1],ff,castlingRights[3],castlingRights[4],castlingRights[5]);
1351 ft = castlingRights[0]; /* Rook file if we have H-side rights */
1353 right = BOARD_RGHT-2;
1354 if(ff == BOARD_RGHT-2) left = right = ff-1; /* special case */
1355 for(k=left; k<=right && ft != NoRights; k++) /* first test if blocked */
1356 if(k != ft && board[0][k] != EmptySquare) ft = NoRights;
1357 for(k=left; k<right && ft != NoRights; k++) /* then if not checked */
1358 if(!ignoreCheck && CheckTest(board, flags, 0, ff, 0, k, FALSE)) ft = NoRights;
1359 if(ft != NoRights && board[0][ft] == WhiteRook) {
1360 if(flags & F_FRC_TYPE_CASTLING) callback(board, flags, WhiteHSideCastleFR, 0, ff, 0, ft, closure);
1361 if(swap) callback(board, flags, WhiteHSideCastleFR, 0, ft, 0, ff, closure);
1364 ft = castlingRights[1]; /* Rook file if we have A-side rights */
1365 left = BOARD_LEFT+2;
1367 if(ff <= BOARD_LEFT+2) { left = ff+1; right = BOARD_LEFT+3; }
1368 for(k=left; k<=right && ft != NoRights; k++) /* first test if blocked */
1369 if(k != ft && board[0][k] != EmptySquare) ft = NoRights;
1370 if(ft == 0 && ff != 1 && board[0][1] != EmptySquare) ft = NoRights; /* Rook can be blocked on b1 */
1371 if(ff > BOARD_LEFT+2)
1372 for(k=left+1; k<=right && ft != NoRights; k++) /* then if not checked */
1373 if(!ignoreCheck && CheckTest(board, flags, 0, ff, 0, k, FALSE)) ft = NoRights;
1374 if(ft != NoRights && board[0][ft] == WhiteRook) {
1375 if(flags & F_FRC_TYPE_CASTLING) callback(board, flags, WhiteASideCastleFR, 0, ff, 0, ft, closure);
1376 if(swap) callback(board, flags, WhiteASideCastleFR, 0, ft, 0, ff, closure);
1380 ff = castlingRights[5]; /* King file if we have any rights */
1381 if(ff != NoRights && board[BOARD_HEIGHT-1][ff] == BlackKing) {
1382 ft = castlingRights[3]; /* Rook file if we have H-side rights */
1384 right = BOARD_RGHT-2;
1385 if(ff == BOARD_RGHT-2) left = right = ff-1; /* special case */
1386 for(k=left; k<=right && ft != NoRights; k++) /* first test if blocked */
1387 if(k != ft && board[BOARD_HEIGHT-1][k] != EmptySquare) ft = NoRights;
1388 for(k=left; k<right && ft != NoRights; k++) /* then if not checked */
1389 if(!ignoreCheck && CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, k, FALSE)) ft = NoRights;
1390 if(ft != NoRights && board[BOARD_HEIGHT-1][ft] == BlackRook) {
1391 if(flags & F_FRC_TYPE_CASTLING) callback(board, flags, BlackHSideCastleFR, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ft, closure);
1392 if(swap) callback(board, flags, BlackHSideCastleFR, BOARD_HEIGHT-1, ft, BOARD_HEIGHT-1, ff, closure);
1395 ft = castlingRights[4]; /* Rook file if we have A-side rights */
1396 left = BOARD_LEFT+2;
1398 if(ff <= BOARD_LEFT+2) { left = ff+1; right = BOARD_LEFT+3; }
1399 for(k=left; k<=right && ft != NoRights; k++) /* first test if blocked */
1400 if(k != ft && board[BOARD_HEIGHT-1][k] != EmptySquare) ft = NoRights;
1401 if(ft == 0 && ff != 1 && board[BOARD_HEIGHT-1][1] != EmptySquare) ft = NoRights; /* Rook can be blocked on b8 */
1402 if(ff > BOARD_LEFT+2)
1403 for(k=left+1; k<=right && ft != NoRights; k++) /* then if not checked */
1404 if(!ignoreCheck && CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, k, FALSE)) ft = NoRights;
1405 if(ft != NoRights && board[BOARD_HEIGHT-1][ft] == BlackRook) {
1406 if(flags & F_FRC_TYPE_CASTLING) callback(board, flags, BlackASideCastleFR, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ft, closure);
1407 if(swap) callback(board, flags, BlackASideCastleFR, BOARD_HEIGHT-1, ft, BOARD_HEIGHT-1, ff, closure);
1424 extern void CheckTestCallback P((Board board, int flags, ChessMove kind,
1425 int rf, int ff, int rt, int ft,
1430 CheckTestCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1432 register CheckTestClosure *cl = (CheckTestClosure *) closure;
1434 if (rt == cl->rking && ft == cl->fking) {
1435 if(xqCheckers[EP_STATUS] >= 2 && xqCheckers[rf][ff]) return; // checker is piece with suspended checking power
1437 xqCheckers[rf][ff] = xqCheckers[EP_STATUS] & 1; // remember who is checking (if status == 1)
1439 if( board[EP_STATUS] == EP_ROYAL_LION && (board[rt][ft] == WhiteLion || board[rt][ft] == BlackLion)
1440 && (gameInfo.variant != VariantLion || board[rf][ff] != WhiteKing && board[rf][ff] != BlackKing) )
1441 cl->check++; // [HGM] lion: forbidden counterstrike against Lion equated to putting yourself in check
1445 /* If the player on move were to move from (rf, ff) to (rt, ft), would
1446 he leave himself in check? Or if rf == -1, is the player on move
1447 in check now? enPassant must be TRUE if the indicated move is an
1448 e.p. capture. The possibility of castling out of a check along the
1449 back rank is not accounted for (i.e., we still return nonzero), as
1450 this is illegal anyway. Return value is the number of times the
1451 king is in check. */
1453 CheckTest (Board board, int flags, int rf, int ff, int rt, int ft, int enPassant)
1455 CheckTestClosure cl;
1456 ChessSquare king = flags & F_WHITE_ON_MOVE ? WhiteKing : BlackKing;
1457 ChessSquare captured = EmptySquare, ep=0, trampled=0;
1458 /* Suppress warnings on uninitialized variables */
1460 if(gameInfo.variant == VariantXiangqi)
1461 king = flags & F_WHITE_ON_MOVE ? WhiteWazir : BlackWazir;
1462 if(gameInfo.variant == VariantKnightmate)
1463 king = flags & F_WHITE_ON_MOVE ? WhiteUnicorn : BlackUnicorn;
1464 if(gameInfo.variant == VariantChu) { // strictly speaking this is not needed, as Chu officially has no check
1465 int r, f, k = king, royals=0, prince = flags & F_WHITE_ON_MOVE ? WhiteMonarch : BlackMonarch;
1466 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++) {
1467 if(board[r][f] == k || board[r][f] == prince) {
1468 if(++royals > 1) return FALSE; // no check if we have two royals (ignores double captureby Lion!)
1469 king = board[r][f]; // remember hich one we had
1476 captured = board[rf][ft];
1477 board[rf][ft] = EmptySquare;
1479 captured = board[rt][ft];
1480 if(killX >= 0) { trampled = board[killY][killX]; board[killY][killX] = EmptySquare; }
1482 if(rf == DROP_RANK) board[rt][ft] = ff; else { // [HGM] drop
1483 board[rt][ft] = board[rf][ff];
1484 board[rf][ff] = EmptySquare;
1486 ep = board[EP_STATUS];
1487 if( captured == WhiteLion || captured == BlackLion ) { // [HGM] lion: Chu Lion-capture rules
1488 ChessSquare victim = killX < 0 ? EmptySquare : trampled;
1489 if( (board[rt][ft] == WhiteLion || board[rt][ft] == BlackLion) && // capturer is Lion
1490 (ff - ft > 1 || ft - ff > 1 || rf - rt > 1 || rt - rf > 1) && // captures from a distance
1491 (victim == EmptySquare || victim == WhitePawn || victim == BlackPawn) ) // no or worthless 'bridge'
1492 board[EP_STATUS] = EP_ROYAL_LION; // on distant Lion x Lion victim must not be pseudo-legally protected
1496 /* For compatibility with ICS wild 9, we scan the board in the
1497 order a1, a2, a3, ... b1, b2, ..., h8 to find the first king,
1498 and we test only whether that one is in check. */
1499 for (cl.fking = BOARD_LEFT+0; cl.fking < BOARD_RGHT; cl.fking++)
1500 for (cl.rking = 0; cl.rking < BOARD_HEIGHT; cl.rking++) {
1501 if (board[cl.rking][cl.fking] == king) {
1503 if(gameInfo.variant == VariantXiangqi) {
1504 /* [HGM] In Xiangqi opposing Kings means check as well */
1506 dir = (king >= BlackPawn) ? -1 : 1;
1507 for( i=cl.rking+dir; i>=0 && i<BOARD_HEIGHT &&
1508 board[i][cl.fking] == EmptySquare; i+=dir );
1509 if(i>=0 && i<BOARD_HEIGHT &&
1510 board[i][cl.fking] == (dir>0 ? BlackWazir : WhiteWazir) )
1513 GenPseudoLegal(board, flags ^ F_WHITE_ON_MOVE, CheckTestCallback, (VOIDSTAR) &cl, EmptySquare);
1514 if(gameInfo.variant != VariantSpartan || cl.check == 0) // in Spartan Chess go on to test if other King is checked too
1515 goto undo_move; /* 2-level break */
1522 if(rf != DROP_RANK) // [HGM] drop
1523 board[rf][ff] = board[rt][ft];
1525 board[rf][ft] = captured;
1526 board[rt][ft] = EmptySquare;
1528 if(killX >= 0) board[killY][killX] = trampled;
1529 board[rt][ft] = captured;
1531 board[EP_STATUS] = ep;
1534 return cl.fking < BOARD_RGHT ? cl.check : 1000; // [HGM] atomic: return 1000 if we have no king
1538 HasLion (Board board, int flags)
1540 int lion = F_WHITE_ON_MOVE & flags ? WhiteLion : BlackLion;
1542 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++)
1543 if(board[r][f] == lion) return 1;
1548 LegalDrop (Board board, int flags, ChessSquare piece, int rt, int ft)
1549 { // [HGM] put drop legality testing in separate routine for clarity
1551 if(appData.debugMode) fprintf(debugFP, "LegalDrop: %d @ %d,%d)\n", piece, ft, rt);
1552 if(board[rt][ft] != EmptySquare) return ImpossibleMove; // must drop to empty square
1553 n = PieceToNumber(piece);
1554 if((gameInfo.holdingsWidth == 0 || (flags & F_WHITE_ON_MOVE ? board[n][BOARD_WIDTH-1] : board[BOARD_HEIGHT-1-n][0]) != piece)
1555 && gameInfo.variant != VariantBughouse) // in bughouse we don't check for availability, because ICS doesn't always tell us
1556 return ImpossibleMove; // piece not available
1557 if(gameInfo.variant == VariantShogi) { // in Shogi lots of drops are forbidden!
1558 if((piece == WhitePawn || piece == WhiteQueen) && rt == BOARD_HEIGHT-1 ||
1559 (piece == BlackPawn || piece == BlackQueen) && rt == 0 ||
1560 piece == WhiteKnight && rt > BOARD_HEIGHT-3 ||
1561 piece == BlackKnight && rt < 2 ) return IllegalMove; // e.g. where dropped piece has no moves
1562 if(piece == WhitePawn || piece == BlackPawn) {
1563 int r, max = 1 + (BOARD_HEIGHT == 7); // two Pawns per file in Tori!
1564 for(r=1; r<BOARD_HEIGHT-1; r++)
1565 if(!(max -= (board[r][ft] == piece))) return IllegalMove; // or there already is a Pawn in file
1566 // should still test if we mate with this Pawn
1568 } else if(gameInfo.variant == VariantSChess) { // only back-rank drops
1569 if (rt != (piece < BlackPawn ? 0 : BOARD_HEIGHT-1)) return IllegalMove;
1571 if( (piece == WhitePawn || piece == BlackPawn) &&
1572 (rt == 0 || rt == BOARD_HEIGHT -1 ) )
1573 return IllegalMove; /* no pawn drops on 1st/8th */
1575 if(appData.debugMode) fprintf(debugFP, "LegalDrop: %d @ %d,%d)\n", piece, ft, rt);
1576 if (!(flags & F_IGNORE_CHECK) &&
1577 CheckTest(board, flags, DROP_RANK, piece, rt, ft, FALSE) ) return IllegalMove;
1578 return flags & F_WHITE_ON_MOVE ? WhiteDrop : BlackDrop;
1581 extern void LegalityTestCallback P((Board board, int flags, ChessMove kind,
1582 int rf, int ff, int rt, int ft,
1586 LegalityTestCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1588 register LegalityTestClosure *cl = (LegalityTestClosure *) closure;
1590 if(board[rt][ft] != EmptySquare || kind==WhiteCapturesEnPassant || kind==BlackCapturesEnPassant)
1591 cl->captures++; // [HGM] losers: count legal captures
1592 if (rf == cl->rf && ff == cl->ff && rt == cl->rt && ft == cl->ft)
1597 LegalityTest (Board board, int flags, int rf, int ff, int rt, int ft, int promoChar)
1599 LegalityTestClosure cl; ChessSquare piece, filterPiece;
1601 if(quickFlag) flags = flags & ~1 | quickFlag & 1; // [HGM] speed: in quick mode quickFlag specifies side-to-move.
1602 if(rf == DROP_RANK) return LegalDrop(board, flags, ff, rt, ft);
1603 piece = filterPiece = board[rf][ff];
1604 if(PieceToChar(piece) == '~') filterPiece = DEMOTED piece;
1606 /* [HGM] Cobra and Falcon are wildcard pieces; consider all their moves legal */
1607 /* (perhaps we should disallow moves that obviously leave us in check?) */
1608 if((piece == WhiteFalcon || piece == BlackFalcon ||
1609 piece == WhiteCobra || piece == BlackCobra) && gameInfo.variant != VariantChu)
1610 return CheckTest(board, flags, rf, ff, rt, ft, FALSE) ? IllegalMove : NormalMove;
1614 cl.rt = rFilter = rt; // [HGM] speed: filter on to-square
1615 cl.ft = fFilter = ft;
1616 cl.kind = IllegalMove;
1617 cl.captures = 0; // [HGM] losers: prepare to count legal captures.
1618 if(flags & F_MANDATORY_CAPTURE) filterPiece = EmptySquare; // [HGM] speed: do not filter in suicide, to find all captures
1619 GenLegal(board, flags, LegalityTestCallback, (VOIDSTAR) &cl, filterPiece);
1620 if((flags & F_MANDATORY_CAPTURE) && cl.captures && board[rt][ft] == EmptySquare
1621 && cl.kind != WhiteCapturesEnPassant && cl.kind != BlackCapturesEnPassant)
1622 return(IllegalMove); // [HGM] losers: if there are legal captures, non-capts are illegal
1624 if(promoChar == 'x') promoChar = NULLCHAR; // [HGM] is this ever the case?
1625 if(gameInfo.variant == VariantSChess && promoChar && promoChar != '=' && board[rf][ff] != WhitePawn && board[rf][ff] != BlackPawn) {
1626 if(board[rf][ff] < BlackPawn) { // white
1627 if(rf != 0) return IllegalMove; // must be on back rank
1628 if(!(board[VIRGIN][ff] & VIRGIN_W)) return IllegalMove; // non-virgin
1629 if(board[PieceToNumber(CharToPiece(ToUpper(promoChar)))][BOARD_WIDTH-2] == 0) return ImpossibleMove;// must be in stock
1630 if(cl.kind == WhiteHSideCastleFR && (ff == BOARD_RGHT-2 || ff == BOARD_RGHT-3)) return ImpossibleMove;
1631 if(cl.kind == WhiteASideCastleFR && (ff == BOARD_LEFT+2 || ff == BOARD_LEFT+3)) return ImpossibleMove;
1633 if(rf != BOARD_HEIGHT-1) return IllegalMove;
1634 if(!(board[VIRGIN][ff] & VIRGIN_B)) return IllegalMove; // non-virgin
1635 if(board[BOARD_HEIGHT-1-PieceToNumber(CharToPiece(ToLower(promoChar)))][1] == 0) return ImpossibleMove;
1636 if(cl.kind == BlackHSideCastleFR && (ff == BOARD_RGHT-2 || ff == BOARD_RGHT-3)) return ImpossibleMove;
1637 if(cl.kind == BlackASideCastleFR && (ff == BOARD_LEFT+2 || ff == BOARD_LEFT+3)) return ImpossibleMove;
1640 if(gameInfo.variant == VariantChu) {
1641 if(cl.kind != NormalMove || promoChar == NULLCHAR || promoChar == '=') return cl.kind;
1642 if(promoChar != '+')
1643 return CharToPiece(promoChar) == EmptySquare ? ImpossibleMove : IllegalMove;
1644 if(PieceToChar(CHUPROMOTED board[rf][ff]) != '+') return ImpossibleMove;
1645 return flags & F_WHITE_ON_MOVE ? WhitePromotion : BlackPromotion;
1647 if(gameInfo.variant == VariantShogi) {
1648 /* [HGM] Shogi promotions. '=' means defer */
1649 if(rf != DROP_RANK && cl.kind == NormalMove) {
1650 ChessSquare piece = board[rf][ff];
1652 if(promoChar == PieceToChar(BlackQueen)) promoChar = NULLCHAR; /* [HGM] Kludge */
1653 if(promoChar == 'd' && (piece == WhiteRook || piece == BlackRook) ||
1654 promoChar == 'h' && (piece == WhiteBishop || piece == BlackBishop) ||
1655 promoChar == 'g' && (piece <= WhiteFerz || piece <= BlackFerz && piece >= BlackPawn) )
1656 promoChar = '+'; // allowed ICS notations
1657 if(appData.debugMode)fprintf(debugFP,"SHOGI promoChar = %c\n", promoChar ? promoChar : '-');
1658 if(promoChar != NULLCHAR && promoChar != '+' && promoChar != '=')
1659 return CharToPiece(promoChar) == EmptySquare ? ImpossibleMove : IllegalMove;
1660 else if(flags & F_WHITE_ON_MOVE) {
1661 if( (int) piece < (int) WhiteWazir &&
1662 (rf >= BOARD_HEIGHT - BOARD_HEIGHT/3 || rt >= BOARD_HEIGHT - BOARD_HEIGHT/3) ) {
1663 if( (piece == WhitePawn || piece == WhiteQueen) && rt > BOARD_HEIGHT-2 ||
1664 piece == WhiteKnight && rt > BOARD_HEIGHT-3) /* promotion mandatory */
1665 cl.kind = promoChar == '=' ? IllegalMove : WhitePromotion;
1666 else /* promotion optional, default is defer */
1667 cl.kind = promoChar == '+' ? WhitePromotion : WhiteNonPromotion;
1668 } else cl.kind = promoChar == '+' ? IllegalMove : NormalMove;
1670 if( (int) piece < (int) BlackWazir && (rf < BOARD_HEIGHT/3 || rt < BOARD_HEIGHT/3) ) {
1671 if( (piece == BlackPawn || piece == BlackQueen) && rt < 1 ||
1672 piece == BlackKnight && rt < 2 ) /* promotion obligatory */
1673 cl.kind = promoChar == '=' ? IllegalMove : BlackPromotion;
1674 else /* promotion optional, default is defer */
1675 cl.kind = promoChar == '+' ? BlackPromotion : BlackNonPromotion;
1676 } else cl.kind = promoChar == '+' ? IllegalMove : NormalMove;
1680 if (promoChar != NULLCHAR) {
1681 if(cl.kind == NormalMove && promoChar == '+') { // allow shogi-style promotion is pieceToChar specifies them
1682 ChessSquare piece = board[rf][ff];
1683 if(piece < BlackPawn ? piece > WhiteMan : piece > BlackMan) return ImpossibleMove; // already promoted
1684 // should test if in zone, really
1685 if(gameInfo.variant == VariantChuChess && (piece == WhiteKnight || piece == BlackKnight) && HasLion(board, flags))
1687 if(PieceToChar(PROMOTED piece) == '+') return flags & F_WHITE_ON_MOVE ? WhitePromotion : BlackPromotion;
1689 if(promoChar == '=') cl.kind = IllegalMove; else // [HGM] shogi: no deferred promotion outside Shogi
1690 if (cl.kind == WhitePromotion || cl.kind == BlackPromotion) {
1691 ChessSquare piece = CharToPiece(flags & F_WHITE_ON_MOVE ? ToUpper(promoChar) : ToLower(promoChar));
1692 if(piece == EmptySquare)
1693 cl.kind = ImpossibleMove; // non-existing piece
1694 if(gameInfo.variant == VariantChuChess && promoChar == 'l' && HasLion(board, flags)) {
1695 cl.kind = IllegalMove; // no two Lions
1696 } else if(gameInfo.variant == VariantSpartan && cl.kind == BlackPromotion ) {
1697 if(promoChar != PieceToChar(BlackKing)) {
1698 if(CheckTest(board, flags, rf, ff, rt, ft, FALSE)) cl.kind = IllegalMove; // [HGM] spartan: only promotion to King was possible
1699 if(piece == BlackLance) cl.kind = ImpossibleMove;
1700 } else { // promotion to King allowed only if we do not have two yet
1701 int r, f, kings = 0;
1702 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++) kings += (board[r][f] == BlackKing);
1703 if(kings == 2) cl.kind = IllegalMove;
1705 } else if(piece == WhitePawn && rt == BOARD_HEIGHT-1 ||
1706 piece == BlackPawn && rt == 0) cl.kind = IllegalMove; // cannot stay Pawn on last rank in any variant
1707 else if((piece == WhiteUnicorn || piece == BlackUnicorn) && gameInfo.variant == VariantKnightmate)
1708 cl.kind = IllegalMove; // promotion to Royal Knight not allowed
1709 else if((piece == WhiteKing || piece == BlackKing) && gameInfo.variant != VariantSuicide && gameInfo.variant != VariantGiveaway)
1710 cl.kind = IllegalMove; // promotion to King usually not allowed
1712 cl.kind = IllegalMove;
1722 extern void MateTestCallback P((Board board, int flags, ChessMove kind,
1723 int rf, int ff, int rt, int ft,
1727 MateTestCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1729 register MateTestClosure *cl = (MateTestClosure *) closure;
1734 /* Return MT_NONE, MT_CHECK, MT_CHECKMATE, or MT_STALEMATE */
1736 MateTest (Board board, int flags)
1739 int inCheck, r, f, myPieces=0, hisPieces=0, nrKing=0;
1740 ChessSquare king = flags & F_WHITE_ON_MOVE ? WhiteKing : BlackKing;
1742 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++) {
1743 // [HGM] losers: Count pieces and kings, to detect other unorthodox winning conditions
1744 nrKing += (board[r][f] == king); // stm has king
1745 if( board[r][f] != EmptySquare ) {
1746 if((int)board[r][f] <= (int)king && (int)board[r][f] >= (int)king - (int)WhiteKing + (int)WhitePawn)
1751 switch(gameInfo.variant) { // [HGM] losers: extinction wins
1752 case VariantShatranj:
1753 if(hisPieces == 1) return myPieces > 1 ? MT_BARE : MT_DRAW;
1757 if(nrKing == 0) return MT_NOKING;
1760 if(myPieces == 1) return MT_BARE;
1763 inCheck = GenLegal(board, flags, MateTestCallback, (VOIDSTAR) &cl, EmptySquare);
1764 // [HGM] 3check: yet to do!
1766 return inCheck ? MT_CHECK : MT_NONE;
1768 if(gameInfo.holdingsWidth && gameInfo.variant != VariantSuper && gameInfo.variant != VariantGreat
1769 && gameInfo.variant != VariantSChess && gameInfo.variant != VariantGrand) { // drop game
1770 int r, f, n, holdings = flags & F_WHITE_ON_MOVE ? BOARD_WIDTH-1 : 0;
1771 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++) if(board[r][f] == EmptySquare) // all empty squares
1772 for(n=0; n<BOARD_HEIGHT; n++) // all pieces in hand
1773 if(board[n][holdings] != EmptySquare) {
1774 int moveType = LegalDrop(board, flags, board[n][holdings], r, f);
1775 if(moveType == WhiteDrop || moveType == BlackDrop) return (inCheck ? MT_CHECK : MT_NONE); // we have legal drop
1778 if(gameInfo.variant == VariantSuicide) // [HGM] losers: always stalemate, since no check, but result varies
1779 return myPieces == hisPieces ? MT_STALEMATE :
1780 myPieces > hisPieces ? MT_STAINMATE : MT_STEALMATE;
1781 else if(gameInfo.variant == VariantLosers) return inCheck ? MT_TRICKMATE : MT_STEALMATE;
1782 else if(gameInfo.variant == VariantGiveaway) return MT_STEALMATE; // no check exists, stalemated = win
1784 return inCheck ? MT_CHECKMATE
1785 : (gameInfo.variant == VariantXiangqi || gameInfo.variant == VariantShatranj || IS_SHOGI(gameInfo.variant)) ?
1786 MT_STAINMATE : MT_STALEMATE;
1791 extern void DisambiguateCallback P((Board board, int flags, ChessMove kind,
1792 int rf, int ff, int rt, int ft,
1796 DisambiguateCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1798 register DisambiguateClosure *cl = (DisambiguateClosure *) closure;
1799 int wildCard = FALSE; ChessSquare piece = board[rf][ff];
1801 // [HGM] wild: for wild-card pieces rt and rf are dummies
1802 if(piece == WhiteFalcon || piece == BlackFalcon ||
1803 piece == WhiteCobra || piece == BlackCobra)
1806 if ((cl->pieceIn == EmptySquare || cl->pieceIn == board[rf][ff]
1807 || PieceToChar(board[rf][ff]) == '~'
1808 && cl->pieceIn == (ChessSquare)(DEMOTED board[rf][ff])
1810 (cl->rfIn == -1 || cl->rfIn == rf) &&
1811 (cl->ffIn == -1 || cl->ffIn == ff) &&
1812 (cl->rtIn == -1 || cl->rtIn == rt || wildCard) &&
1813 (cl->ftIn == -1 || cl->ftIn == ft || wildCard)) {
1816 if(cl->count == 1 || board[rt][ft] != EmptySquare) {
1817 // [HGM] oneclick: if multiple moves, be sure we remember capture
1818 cl->piece = board[rf][ff];
1821 cl->rt = wildCard ? cl->rtIn : rt;
1822 cl->ft = wildCard ? cl->ftIn : ft;
1825 cl->captures += (board[rt][ft] != EmptySquare); // [HGM] oneclick: count captures
1830 Disambiguate (Board board, int flags, DisambiguateClosure *closure)
1832 int illegal = 0; char c = closure->promoCharIn;
1834 if(quickFlag) flags = flags & ~1 | quickFlag & 1; // [HGM] speed: in quick mode quickFlag specifies side-to-move.
1835 closure->count = closure->captures = 0;
1836 closure->rf = closure->ff = closure->rt = closure->ft = 0;
1837 closure->kind = ImpossibleMove;
1838 rFilter = closure->rtIn; // [HGM] speed: only consider moves to given to-square
1839 fFilter = closure->ftIn;
1840 if(quickFlag) { // [HGM] speed: try without check test first, because if that is not ambiguous, we are happy
1841 GenLegal(board, flags|F_IGNORE_CHECK, DisambiguateCallback, (VOIDSTAR) closure, closure->pieceIn);
1842 if(closure->count > 1) { // gamble did not pay off. retry with check test to resolve ambiguity
1843 closure->count = closure->captures = 0;
1844 closure->rf = closure->ff = closure->rt = closure->ft = 0;
1845 closure->kind = ImpossibleMove;
1846 GenLegal(board, flags, DisambiguateCallback, (VOIDSTAR) closure, closure->pieceIn); // [HGM] speed: only pieces of requested type
1849 GenLegal(board, flags, DisambiguateCallback, (VOIDSTAR) closure, closure->pieceIn); // [HGM] speed: only pieces of requested type
1850 if (closure->count == 0) {
1851 /* See if it's an illegal move due to check */
1853 GenLegal(board, flags|F_IGNORE_CHECK, DisambiguateCallback, (VOIDSTAR) closure, closure->pieceIn);
1854 if (closure->count == 0) {
1855 /* No, it's not even that */
1856 if(!appData.testLegality && closure->pieceIn != EmptySquare) {
1857 int f, r; // if there is only a single piece of the requested type on the board, use that
1858 closure->rt = closure->rtIn, closure->ft = closure->ftIn;
1859 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++)
1860 if(board[r][f] == closure->pieceIn) closure->count++, closure->rf = r, closure->ff = f;
1861 if(closure->count > 1) illegal = 0; // ambiguous
1863 if(closure->count == 0) {
1864 if (appData.debugMode) { int i, j;
1865 for(i=BOARD_HEIGHT-1; i>=0; i--) {
1866 for(j=0; j<BOARD_WIDTH; j++)
1867 fprintf(debugFP, "%3d", (int) board[i][j]);
1868 fprintf(debugFP, "\n");
1876 if (c == 'x') c = NULLCHAR; // get rid of any 'x' (which should never happen?)
1877 if(gameInfo.variant == VariantSChess && c && c != '=' && closure->piece != WhitePawn && closure->piece != BlackPawn) {
1878 if(closure->piece < BlackPawn) { // white
1879 if(closure->rf != 0) closure->kind = IllegalMove; // must be on back rank
1880 if(!(board[VIRGIN][closure->ff] & VIRGIN_W)) closure->kind = IllegalMove; // non-virgin
1881 if(board[PieceToNumber(CharToPiece(ToUpper(c)))][BOARD_WIDTH-2] == 0) closure->kind = ImpossibleMove;// must be in stock
1882 if(closure->kind == WhiteHSideCastleFR && (closure->ff == BOARD_RGHT-2 || closure->ff == BOARD_RGHT-3)) closure->kind = ImpossibleMove;
1883 if(closure->kind == WhiteASideCastleFR && (closure->ff == BOARD_LEFT+2 || closure->ff == BOARD_LEFT+3)) closure->kind = ImpossibleMove;
1885 if(closure->rf != BOARD_HEIGHT-1) closure->kind = IllegalMove;
1886 if(!(board[VIRGIN][closure->ff] & VIRGIN_B)) closure->kind = IllegalMove; // non-virgin
1887 if(board[BOARD_HEIGHT-1-PieceToNumber(CharToPiece(ToLower(c)))][1] == 0) closure->kind = ImpossibleMove;
1888 if(closure->kind == BlackHSideCastleFR && (closure->ff == BOARD_RGHT-2 || closure->ff == BOARD_RGHT-3)) closure->kind = ImpossibleMove;
1889 if(closure->kind == BlackASideCastleFR && (closure->ff == BOARD_LEFT+2 || closure->ff == BOARD_LEFT+3)) closure->kind = ImpossibleMove;
1892 if(gameInfo.variant == VariantChu) {
1893 if(c == '+') closure->kind = (flags & F_WHITE_ON_MOVE ? WhitePromotion : BlackPromotion); // for now, accept any
1895 if(gameInfo.variant == VariantShogi) {
1896 /* [HGM] Shogi promotions. On input, '=' means defer, '+' promote. Afterwards, c is set to '+' for promotions, NULL other */
1897 if(closure->rfIn != DROP_RANK && closure->kind == NormalMove) {
1898 ChessSquare piece = closure->piece;
1899 if (c == 'd' && (piece == WhiteRook || piece == BlackRook) ||
1900 c == 'h' && (piece == WhiteBishop || piece == BlackBishop) ||
1901 c == 'g' && (piece <= WhiteFerz || piece <= BlackFerz && piece >= BlackPawn) )
1902 c = '+'; // allowed ICS notations
1903 if(c != NULLCHAR && c != '+' && c != '=') closure->kind = IllegalMove; // otherwise specifying a piece is illegal
1904 else if(flags & F_WHITE_ON_MOVE) {
1905 if( (int) piece < (int) WhiteWazir &&
1906 (closure->rf >= BOARD_HEIGHT-(BOARD_HEIGHT/3) || closure->rt >= BOARD_HEIGHT-(BOARD_HEIGHT/3)) ) {
1907 if( (piece == WhitePawn || piece == WhiteQueen) && closure->rt > BOARD_HEIGHT-2 ||
1908 piece == WhiteKnight && closure->rt > BOARD_HEIGHT-3) /* promotion mandatory */
1909 closure->kind = c == '=' ? IllegalMove : WhitePromotion;
1910 else /* promotion optional, default is defer */
1911 closure->kind = c == '+' ? WhitePromotion : WhiteNonPromotion;
1912 } else closure->kind = c == '+' ? IllegalMove : NormalMove;
1914 if( (int) piece < (int) BlackWazir && (closure->rf < BOARD_HEIGHT/3 || closure->rt < BOARD_HEIGHT/3) ) {
1915 if( (piece == BlackPawn || piece == BlackQueen) && closure->rt < 1 ||
1916 piece == BlackKnight && closure->rt < 2 ) /* promotion obligatory */
1917 closure->kind = c == '=' ? IllegalMove : BlackPromotion;
1918 else /* promotion optional, default is defer */
1919 closure->kind = c == '+' ? BlackPromotion : BlackNonPromotion;
1920 } else closure->kind = c == '+' ? IllegalMove : NormalMove;
1923 if(closure->kind == WhitePromotion || closure->kind == BlackPromotion) c = '+'; else
1924 if(closure->kind == WhiteNonPromotion || closure->kind == BlackNonPromotion) c = '=';
1926 if (closure->kind == WhitePromotion || closure->kind == BlackPromotion) {
1927 if(c == NULLCHAR) { // missing promoChar on mandatory promotion; use default for variant
1928 if(gameInfo.variant == VariantShatranj || gameInfo.variant == VariantCourier ||
1929 gameInfo.variant == VariantMakruk || gameInfo.variant == VariantASEAN)
1930 c = PieceToChar(BlackFerz);
1931 else if(gameInfo.variant == VariantGreat)
1932 c = PieceToChar(BlackMan);
1933 else if(gameInfo.variant == VariantGrand)
1934 closure->kind = closure->rt != 0 && closure->rt != BOARD_HEIGHT-1 ? NormalMove : AmbiguousMove; // no default in Grand Chess
1936 c = PieceToChar(BlackQueen);
1937 } else if(c == '=') closure->kind = IllegalMove; // no deferral outside Shogi
1938 else if(c == 'l' && gameInfo.variant == VariantChuChess && HasLion(board, flags)) closure->kind = IllegalMove;
1939 } else if (c == '+') { // '+' outside shogi, check if pieceToCharTable enabled it
1940 ChessSquare p = closure->piece;
1941 if(p > WhiteMan && p < BlackPawn || p > BlackMan || PieceToChar(PROMOTED p) != '+')
1942 closure->kind = ImpossibleMove; // used on non-promotable piece
1943 else if(gameInfo.variant == VariantChuChess && HasLion(board, flags)) closure->kind = IllegalMove;
1944 } else if (c != NULLCHAR) closure->kind = IllegalMove;
1946 closure->promoChar = ToLower(c); // this can be NULLCHAR! Note we keep original promoChar even if illegal.
1947 if(c != '+' && c != '=' && c != NULLCHAR && CharToPiece(flags & F_WHITE_ON_MOVE ? ToUpper(c) : ToLower(c)) == EmptySquare)
1948 closure->kind = ImpossibleMove; // but we cannot handle non-existing piece types!
1949 if (closure->count > 1) {
1950 closure->kind = AmbiguousMove;
1953 /* Note: If more than one illegal move matches, but no legal
1954 moves, we return IllegalMove, not AmbiguousMove. Caller
1955 can look at closure->count to detect this.
1957 closure->kind = IllegalMove;
1971 } CoordsToAlgebraicClosure;
1973 extern void CoordsToAlgebraicCallback P((Board board, int flags,
1974 ChessMove kind, int rf, int ff,
1975 int rt, int ft, VOIDSTAR closure));
1978 CoordsToAlgebraicCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1980 register CoordsToAlgebraicClosure *cl =
1981 (CoordsToAlgebraicClosure *) closure;
1983 if ((rt == cl->rt && ft == cl->ft || rt == rf && ft == ff) && // [HGM] null move matches any toSquare
1984 (board[rf][ff] == cl->piece
1985 || PieceToChar(board[rf][ff]) == '~' &&
1986 (ChessSquare) (DEMOTED board[rf][ff]) == cl->piece)
1990 cl->kind = kind; /* this is the move we want */
1992 cl->file++; /* need file to rule out this move */
1996 cl->rank++; /* need rank to rule out this move */
1998 cl->either++; /* rank or file will rule out this move */
2004 /* Convert coordinates to normal algebraic notation.
2005 promoChar must be NULLCHAR or 'x' if not a promotion.
2008 CoordsToAlgebraic (Board board, int flags, int rf, int ff, int rt, int ft, int promoChar, char out[MOVE_LEN])
2012 char *outp = out, c, capture;
2013 CoordsToAlgebraicClosure cl;
2015 if (rf == DROP_RANK) {
2016 if(ff == EmptySquare) { strncpy(outp, "--",3); return NormalMove; } // [HGM] pass
2017 /* Bughouse piece drop */
2018 *outp++ = ToUpper(PieceToChar((ChessSquare) ff));
2023 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2025 return (flags & F_WHITE_ON_MOVE) ? WhiteDrop : BlackDrop;
2028 if (promoChar == 'x') promoChar = NULLCHAR;
2029 piece = board[rf][ff];
2030 if(PieceToChar(piece)=='~') piece = (ChessSquare)(DEMOTED piece);
2035 kind = LegalityTest(board, flags, rf, ff, rt, ft, promoChar);
2036 if (kind == IllegalMove && !(flags&F_IGNORE_CHECK)) {
2037 /* Keep short notation if move is illegal only because it
2038 leaves the player in check, but still return IllegalMove */
2039 kind = LegalityTest(board, flags|F_IGNORE_CHECK, rf, ff, rt, ft, promoChar);
2040 if (kind == IllegalMove) break;
2045 capture = board[rt][ft] != EmptySquare || kind == WhiteCapturesEnPassant || kind == BlackCapturesEnPassant;
2046 if (ff == ft && !capture) { /* [HGM] Xiangqi has straight noncapts! */
2047 /* Non-capture; use style "e5" */
2050 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2052 /* Capture; use style "exd5" */
2054 *outp++ = 'x'; /* [HGM] Xiangqi has sideway noncaptures across river! */
2058 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2060 /* Use promotion suffix style "=Q" */
2062 if (promoChar != NULLCHAR) {
2063 if(IS_SHOGI(gameInfo.variant)) {
2064 /* [HGM] ... but not in Shogi! */
2065 *outp++ = promoChar == '=' ? '=' : '+';
2068 *outp++ = ToUpper(promoChar);
2077 /* Fabien moved code: FRC castling first (if KxR), wild castling second */
2078 /* Code added by Tord: FRC castling. */
2079 if((piece == WhiteKing && board[rt][ft] == WhiteRook) ||
2080 (piece == BlackKing && board[rt][ft] == BlackRook)) {
2082 safeStrCpy(out, "O-O", MOVE_LEN);
2084 safeStrCpy(out, "O-O-O", MOVE_LEN);
2085 return LegalityTest(board, flags, rf, ff, rt, ft, promoChar);
2087 /* End of code added by Tord */
2088 /* Test for castling or ICS wild castling */
2089 /* Use style "O-O" (oh-oh) for PGN compatibility */
2090 else if (rf == rt &&
2091 rf == ((piece == WhiteKing) ? 0 : BOARD_HEIGHT-1) &&
2092 (ft - ff > 1 || ff - ft > 1) && // No castling if legal King move (on narrow boards!)
2093 ((ff == BOARD_WIDTH>>1 && (ft == BOARD_LEFT+2 || ft == BOARD_RGHT-2)) ||
2094 (ff == (BOARD_WIDTH-1)>>1 && (ft == BOARD_LEFT+1 || ft == BOARD_RGHT-3)))) {
2095 if(ft==BOARD_LEFT+1 || ft==BOARD_RGHT-2)
2096 snprintf(out, MOVE_LEN, "O-O%c%c", promoChar ? '/' : 0, ToUpper(promoChar));
2098 snprintf(out, MOVE_LEN, "O-O-O%c%c", promoChar ? '/' : 0, ToUpper(promoChar));
2100 /* This notation is always unambiguous, unless there are
2101 kings on both the d and e files, with "wild castling"
2102 possible for the king on the d file and normal castling
2103 possible for the other. ICS rules for wild 9
2104 effectively make castling illegal for either king in
2105 this situation. So I am not going to worry about it;
2106 I'll just generate an ambiguous O-O in this case.
2108 return LegalityTest(board, flags, rf, ff, rt, ft, promoChar);
2111 /* else fall through */
2116 cl.rt = rFilter = rt; // [HGM] speed: filter on to-square
2117 cl.ft = fFilter = ft;
2119 cl.kind = IllegalMove;
2120 cl.rank = cl.file = cl.either = 0;
2121 c = PieceToChar(piece) ;
2122 GenLegal(board, flags, CoordsToAlgebraicCallback, (VOIDSTAR) &cl, c!='~' ? piece : (DEMOTED piece)); // [HGM] speed
2124 if (cl.kind == IllegalMove && !(flags&F_IGNORE_CHECK)) {
2125 /* Generate pretty moves for moving into check, but
2126 still return IllegalMove.
2128 GenLegal(board, flags|F_IGNORE_CHECK, CoordsToAlgebraicCallback, (VOIDSTAR) &cl, c!='~' ? piece : (DEMOTED piece));
2129 if (cl.kind == IllegalMove) break;
2130 cl.kind = IllegalMove;
2133 /* Style is "Nf3" or "Nxf7" if this is unambiguous,
2134 else "Ngf3" or "Ngxf7",
2135 else "N1f3" or "N5xf7",
2136 else "Ng1f3" or "Ng5xf7".
2138 if( c == '~' || c == '+') {
2139 /* [HGM] print nonexistent piece as its demoted version */
2140 piece = (ChessSquare) (DEMOTED piece - 11*(gameInfo.variant == VariantChu));
2142 if(c=='+') *outp++ = c;
2143 *outp++ = ToUpper(PieceToChar(piece));
2145 if (cl.file || (cl.either && !cl.rank)) {
2151 else { *outp++ = (rf+ONE-'0')/10 + '0';*outp++ = (rf+ONE-'0')%10 + '0'; }
2154 if(board[rt][ft] != EmptySquare)
2160 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2161 if (IS_SHOGI(gameInfo.variant)) {
2162 /* [HGM] in Shogi non-pawns can promote */
2163 *outp++ = promoChar; // Don't bother to correct move type, return value is never used!
2165 else if (gameInfo.variant == VariantChuChess && promoChar ||
2166 gameInfo.variant != VariantSuper && promoChar &&
2167 (piece == WhiteLance || piece == BlackLance) ) { // Lance sometimes represents Pawn
2169 *outp++ = ToUpper(promoChar);
2171 else if (gameInfo.variant == VariantSChess && promoChar) { // and in S-Chess we have gating
2173 *outp++ = ToUpper(promoChar);
2179 /* Moving a nonexistent piece */
2183 /* Not a legal move, even ignoring check.
2184 If there was a piece on the from square,
2185 use style "Ng1g3" or "Ng1xe8";
2186 if there was a pawn or nothing (!),
2187 use style "g1g3" or "g1xe8". Use "x"
2188 if a piece was on the to square, even
2189 a piece of the same color.
2193 if (piece != EmptySquare && piece != WhitePawn && piece != BlackPawn) {
2195 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<=BOARD_RGHT; f++)
2196 c += (board[r][f] == piece); // count on-board pieces of given type
2197 *outp++ = ToUpper(PieceToChar(piece));
2199 if(c != 1) { // [HGM] but if there is only one piece of the mentioned type, no from-square, thank you!
2203 else { *outp++ = (rf+ONE-'0')/10 + '0';*outp++ = (rf+ONE-'0')%10 + '0'; }
2205 if (board[rt][ft] != EmptySquare) *outp++ = 'x';
2209 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2210 /* Use promotion suffix style "=Q" */
2211 if (promoChar != NULLCHAR && promoChar != 'x') {
2213 *outp++ = ToUpper(promoChar);
2220 // [HGM] XQ: the following code serves to detect perpetual chasing (Asian rules)
2229 // I guess the following variables logically belong in the closure too, but I was too lazy and used globals
2231 int preyStackPointer, chaseStackPointer;
2234 unsigned char rf, ff, rt, ft;
2238 unsigned char rank, file;
2244 // there are three new callbacks for use with GenLegal: for adding captures, deleting them, and finding a recapture
2246 extern void AtacksCallback P((Board board, int flags, ChessMove kind,
2247 int rf, int ff, int rt, int ft,
2251 AttacksCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
2252 { // For adding captures that can lead to chase indictment to the chaseStack
2253 if(board[rt][ft] == EmptySquare) return; // non-capture
2254 if(board[rt][ft] == WhitePawn && rt < BOARD_HEIGHT/2) return; // Pawn before river can be chased
2255 if(board[rt][ft] == BlackPawn && rt >= BOARD_HEIGHT/2) return; // Pawn before river can be chased
2256 if(board[rf][ff] == WhitePawn || board[rf][ff] == BlackPawn) return; // Pawns are allowed to chase
2257 if(board[rf][ff] == WhiteWazir || board[rf][ff] == BlackWazir) return; // King is allowed to chase
2258 // move cannot be excluded from being a chase trivially (based on attacker and victim); save it on chaseStack
2259 chaseStack[chaseStackPointer].rf = rf;
2260 chaseStack[chaseStackPointer].ff = ff;
2261 chaseStack[chaseStackPointer].rt = rt;
2262 chaseStack[chaseStackPointer].ft = ft;
2263 chaseStackPointer++;
2266 extern void ExistingAtacksCallback P((Board board, int flags, ChessMove kind,
2267 int rf, int ff, int rt, int ft,
2271 ExistingAttacksCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
2272 { // for removing pre-exsting captures from the chaseStack, to be left with newly created ones
2274 register ChaseClosure *cl = (ChaseClosure *) closure; //closure tells us the move played in the repeat loop
2276 if(board[rt][ft] == EmptySquare) return; // no capture
2277 if(rf == cl->rf && ff == cl->ff) { // attacks with same piece from new position are not considered new
2278 rf = cl->rt; ff = cl->ft; // doctor their fromSquare so they will be recognized in chaseStack
2280 // search move in chaseStack, and delete it if it occurred there (as we know now it is not a new capture)
2281 for(i=0; i<chaseStackPointer; i++) {
2282 if(chaseStack[i].rf == rf && chaseStack[i].ff == ff &&
2283 chaseStack[i].rt == rt && chaseStack[i].ft == ft ) {
2284 // move found on chaseStack, delete it by overwriting with move popped from top of chaseStack
2285 chaseStack[i] = chaseStack[--chaseStackPointer];
2291 extern void ProtectedCallback P((Board board, int flags, ChessMove kind,
2292 int rf, int ff, int rt, int ft,
2296 ProtectedCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
2297 { // for determining if a piece (given through the closure) is protected
2298 register ChaseClosure *cl = (ChaseClosure *) closure; // closure tells us where to recapture
2300 if(rt == cl->rt && ft == cl->ft) cl->recaptures++; // count legal recaptures to this square
2301 if(appData.debugMode && board[rt][ft] != EmptySquare)
2302 fprintf(debugFP, "try %c%c%c%c=%d\n", ff+AAA, rf+ONE,ft+AAA, rt+ONE, cl->recaptures);
2305 extern char moveList[MAX_MOVES][MOVE_LEN];
2308 PerpetualChase (int first, int last)
2309 { // this routine detects if the side to move in the 'first' position is perpetually chasing (when not checking)
2312 ChessSquare captured;
2314 preyStackPointer = 0; // clear stack of chased pieces
2315 for(i=first; i<last; i+=2) { // for all positions with same side to move
2316 if(appData.debugMode) fprintf(debugFP, "judge position %i\n", i);
2317 chaseStackPointer = 0; // clear stack that is going to hold possible chases
2318 // determine all captures possible after the move, and put them on chaseStack
2319 GenLegal(boards[i+1], PosFlags(i), AttacksCallback, &cl, EmptySquare);
2320 if(appData.debugMode) { int n;
2321 for(n=0; n<chaseStackPointer; n++)
2322 fprintf(debugFP, "%c%c%c%c ", chaseStack[n].ff+AAA, chaseStack[n].rf+ONE,
2323 chaseStack[n].ft+AAA, chaseStack[n].rt+ONE);
2324 fprintf(debugFP, ": all capts\n");
2326 // determine all captures possible before the move, and delete them from chaseStack
2327 cl.rf = moveList[i][1]-ONE; // prepare closure to pass move that led from i to i+1
2328 cl.ff = moveList[i][0]-AAA+BOARD_LEFT;
2329 cl.rt = moveList[i][3]-ONE;
2330 cl.ft = moveList[i][2]-AAA+BOARD_LEFT;
2331 CopyBoard(xqCheckers, nullBoard); xqCheckers[EP_STATUS] = 1; // giant kludge to make GenLegal ignore pre-existing checks
2332 GenLegal(boards[i], PosFlags(i), ExistingAttacksCallback, &cl, EmptySquare);
2333 xqCheckers[EP_STATUS] = 0; // disable the generation of quasi-legal moves again
2334 if(appData.debugMode) { int n;
2335 for(n=0; n<chaseStackPointer; n++)
2336 fprintf(debugFP, "%c%c%c%c ", chaseStack[n].ff+AAA, chaseStack[n].rf+ONE,
2337 chaseStack[n].ft+AAA, chaseStack[n].rt+ONE);
2338 fprintf(debugFP, ": new capts after %c%c%c%c\n", cl.ff+AAA, cl.rf+ONE, cl.ft+AAA, cl.rt+ONE);
2340 // chaseSack now contains all captures made possible by the move
2341 for(j=0; j<chaseStackPointer; j++) { // run through chaseStack to identify true chases
2342 int attacker = (int)boards[i+1][chaseStack[j].rf][chaseStack[j].ff];
2343 int victim = (int)boards[i+1][chaseStack[j].rt][chaseStack[j].ft];
2345 if(attacker >= (int) BlackPawn) attacker = BLACK_TO_WHITE attacker; // convert to white, as piecee type
2346 if(victim >= (int) BlackPawn) victim = BLACK_TO_WHITE victim;
2348 if((attacker == WhiteKnight || attacker == WhiteCannon) && victim == WhiteRook)
2349 continue; // C or H attack on R is always chase; leave on chaseStack
2351 if(attacker == victim) {
2352 if(LegalityTest(boards[i+1], PosFlags(i+1), chaseStack[j].rt,
2353 chaseStack[j].ft, chaseStack[j].rf, chaseStack[j].ff, NULLCHAR) == NormalMove) {
2354 // we can capture back with equal piece, so this is no chase but a sacrifice
2355 chaseStack[j] = chaseStack[--chaseStackPointer]; // delete the capture from the chaseStack
2356 j--; /* ! */ continue;
2361 // the attack is on a lower piece, or on a pinned or blocked equal one
2362 CopyBoard(xqCheckers, nullBoard); xqCheckers[EP_STATUS] = 1;
2363 CheckTest(boards[i+1], PosFlags(i+1), -1, -1, -1, -1, FALSE); // if we deliver check with our move, the checkers get marked
2364 // test if the victim is protected by a true protector. First make the capture.
2365 captured = boards[i+1][chaseStack[j].rt][chaseStack[j].ft];
2366 boards[i+1][chaseStack[j].rt][chaseStack[j].ft] = boards[i+1][chaseStack[j].rf][chaseStack[j].ff];
2367 boards[i+1][chaseStack[j].rf][chaseStack[j].ff] = EmptySquare;
2368 // Then test if the opponent can recapture
2369 cl.recaptures = 0; // prepare closure to pass recapture square and count moves to it
2370 cl.rt = chaseStack[j].rt;
2371 cl.ft = chaseStack[j].ft;
2372 if(appData.debugMode) {
2373 fprintf(debugFP, "test if we can recapture %c%c\n", cl.ft+AAA, cl.rt+ONE);
2375 xqCheckers[EP_STATUS] = 2; // causes GenLegal to ignore the checks we delivered with the move, in real life evaded before we captured
2376 GenLegal(boards[i+1], PosFlags(i+1), ProtectedCallback, &cl, EmptySquare); // try all moves
2377 xqCheckers[EP_STATUS] = 0; // disable quasi-legal moves again
2378 // unmake the capture
2379 boards[i+1][chaseStack[j].rf][chaseStack[j].ff] = boards[i+1][chaseStack[j].rt][chaseStack[j].ft];
2380 boards[i+1][chaseStack[j].rt][chaseStack[j].ft] = captured;
2381 // if a recapture was found, piece is protected, and we are not chasing it.
2382 if(cl.recaptures) { // attacked piece was defended by true protector, no chase
2383 chaseStack[j] = chaseStack[--chaseStackPointer]; // so delete from chaseStack
2387 // chaseStack now contains all moves that chased
2388 if(appData.debugMode) { int n;
2389 for(n=0; n<chaseStackPointer; n++)
2390 fprintf(debugFP, "%c%c%c%c ", chaseStack[n].ff+AAA, chaseStack[n].rf+ONE,
2391 chaseStack[n].ft+AAA, chaseStack[n].rt+ONE);
2392 fprintf(debugFP, ": chases\n");
2394 if(i == first) { // copy all people chased by first move of repeat cycle to preyStack
2395 for(j=0; j<chaseStackPointer; j++) {
2396 preyStack[j].rank = chaseStack[j].rt;
2397 preyStack[j].file = chaseStack[j].ft;
2399 preyStackPointer = chaseStackPointer;
2402 for(j=0; j<chaseStackPointer; j++) {
2403 for(k=0; k<preyStackPointer; k++) {
2404 // search the victim of each chase move on the preyStack (first occurrence)
2405 if(chaseStack[j].ft == preyStack[k].file && chaseStack[j].rt == preyStack[k].rank ) {
2406 if(k < tail) break; // piece was already identified as still being chased
2407 preyStack[preyStackPointer] = preyStack[tail]; // move chased piece to bottom part of preyStack
2408 preyStack[tail] = preyStack[k]; // by swapping
2409 preyStack[k] = preyStack[preyStackPointer];
2415 preyStackPointer = tail; // keep bottom part of preyStack, popping pieces unchased on move i.
2416 if(appData.debugMode) { int n;
2417 for(n=0; n<preyStackPointer; n++)
2418 fprintf(debugFP, "%c%c ", preyStack[n].file+AAA, preyStack[n].rank+ONE);
2419 fprintf(debugFP, "always chased upto ply %d\n", i);
2421 // now adjust the location of the chased pieces according to opponent move
2422 for(j=0; j<preyStackPointer; j++) {
2423 if(preyStack[j].rank == moveList[i+1][1]-ONE &&
2424 preyStack[j].file == moveList[i+1][0]-AAA+BOARD_LEFT) {
2425 preyStack[j].rank = moveList[i+1][3]-ONE;
2426 preyStack[j].file = moveList[i+1][2]-AAA+BOARD_LEFT;
2431 return preyStackPointer ? 256*(preyStack[preyStackPointer].file - BOARD_LEFT + AAA) + (preyStack[preyStackPointer].rank + ONE)
2432 : 0; // if any piece was left on preyStack, it has been perpetually chased,and we return the