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;
259 if(expo > 1 && dx == 0 && dy == 0) { // castling indicated by O + number
263 for(dir=0, bit=1; dir<8; dir++, bit += bit) { // loop over directions
264 int i = expo, vx, vy;
265 if(!(bit & dirSet)) continue; // does not move in this direction
266 vx = dx*rot[dir][0] + dy*rot[dir][1]; // rotate step vector
267 vy = dx*rot[dir][2] + dy*rot[dir][3];
268 x = f; y = r; // start square
270 x += vx; y += vy; // step to next square
271 if(y < 0 || y >= BOARD_HEIGHT || x < BOARD_LEFT || x >= BOARD_RGHT) break;
272 if(!jump && board[y - vy + vy/2][x - vx + vx/2] != EmptySquare) break; // blocked
273 if(jump > 1 && board[y - vy + vy/2][x - vx + vx/2] == EmptySquare) break; // no hop
274 if(board[y][x] < BlackPawn) occup = 1; else
275 if(board[y][x] < EmptySquare) occup = 2; else
277 if(mode & 8 && y == board[EP_RANK] && occup == 4 && board[EP_FILE] == x) { // to e.p. square
278 cb(board, flags, mine == 1 ? WhiteCapturesEnPassant : BlackCapturesEnPassant, r, f, y, x, cl);
280 if(mode & 16) { // castling
281 i = 2; // kludge to elongate move indefinitely
282 if(occup == 4) continue; // skip empty squares
283 if(x == BOARD_LEFT && board[y][x] == initialPosition[y][x]) // reached initial corner piece
284 cb(board, flags, mine == 1 ? WhiteQueenSideCastle : BlackQueenSideCastle, r, f, y, f - expo, cl);
285 if(x == BOARD_RGHT-1 && board[y][x] == initialPosition[y][x])
286 cb(board, flags, mine == 1 ? WhiteKingSideCastle : BlackKingSideCastle, r, f, y, f + expo, cl);
289 if(occup & mode) cb(board, flags, NormalMove, r, f, y, x, cl); // allowed, generate
290 if(occup != 4) break; // not valid transit square
293 dx = dy = 1; dirSet = 0x99; // prepare for diagonal moves of K,Q
294 } while(retry--); // and start doing them
298 // [HGM] move generation now based on hierarchy of subroutines for rays and combinations of rays
301 SlideForward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
306 if (rt >= BOARD_HEIGHT) break;
307 if (SameColor(board[rf][ff], board[rt][ft])) break;
308 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
309 if (board[rt][ft] != EmptySquare) break;
314 SlideBackward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
320 if (SameColor(board[rf][ff], board[rt][ft])) break;
321 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
322 if (board[rt][ft] != EmptySquare) break;
327 SlideVertical (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
329 SlideForward(board, flags, rf, ff, callback, closure);
330 SlideBackward(board, flags, rf, ff, callback, closure);
334 SlideSideways (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
336 int i, s, rt = rf, ft;
337 for(s = -1; s <= 1; s+= 2) {
340 if (ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
341 if (SameColor(board[rf][ff], board[rt][ft])) break;
342 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
343 if (board[rt][ft] != EmptySquare) break;
349 SlideDiagForward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
352 for(s = -1; s <= 1; s+= 2) {
356 if (rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
357 if (SameColor(board[rf][ff], board[rt][ft])) break;
358 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
359 if (board[rt][ft] != EmptySquare) break;
365 SlideDiagBackward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
368 for(s = -1; s <= 1; s+= 2) {
372 if (rt < 0 || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
373 if (SameColor(board[rf][ff], board[rt][ft])) break;
374 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
375 if (board[rt][ft] != EmptySquare) break;
381 Rook (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
383 SlideVertical(board, flags, rf, ff, callback, closure);
384 SlideSideways(board, flags, rf, ff, callback, closure);
388 Bishop (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
390 SlideDiagForward(board, flags, rf, ff, callback, closure);
391 SlideDiagBackward(board, flags, rf, ff, callback, closure);
395 Sting (Board board, int flags, int rf, int ff, int dy, int dx, MoveCallback callback, VOIDSTAR closure)
396 { // Lion-like move of Horned Falcon and Souring Eagle
397 int ft = ff + dx, rt = rf + dy;
398 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) return;
399 if (!SameColor(board[rf][ff], board[rt][ft]))
400 callback(board, flags, board[rt][ft] != EmptySquare ? FirstLeg : NormalMove, rf, ff, rt, ft, closure);
402 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) return;
403 if (!SameColor(board[rf][ff], board[rt][ft]))
404 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
408 StepForward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
410 int ft = ff, rt = rf + 1;
411 if (rt >= BOARD_HEIGHT) return;
412 if (SameColor(board[rf][ff], board[rt][ft])) return;
413 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
417 StepBackward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
419 int ft = ff, rt = rf - 1;
421 if (SameColor(board[rf][ff], board[rt][ft])) return;
422 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
426 StepSideways (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
430 if (!(rt >= BOARD_HEIGHT || ft >= BOARD_RGHT) && !SameColor(board[rf][ff], board[rt][ft]))
431 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
433 if (!(rt >= BOARD_HEIGHT || ft < BOARD_LEFT) && !SameColor(board[rf][ff], board[rt][ft]))
434 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
438 StepDiagForward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
441 if (rt >= BOARD_HEIGHT) return;
443 if (!(rt >= BOARD_HEIGHT || ft >= BOARD_RGHT) && !SameColor(board[rf][ff], board[rt][ft]))
444 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
446 if (!(rt >= BOARD_HEIGHT || ft < BOARD_LEFT) && !SameColor(board[rf][ff], board[rt][ft]))
447 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
451 StepDiagBackward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
456 if (!(rt < 0 || ft >= BOARD_RGHT) && !SameColor(board[rf][ff], board[rt][ft]))
457 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
459 if (!(rt < 0 || ft < BOARD_LEFT) && !SameColor(board[rf][ff], board[rt][ft]))
460 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
464 StepVertical (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
466 StepForward(board, flags, rf, ff, callback, closure);
467 StepBackward(board, flags, rf, ff, callback, closure);
471 Ferz (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
473 StepDiagForward(board, flags, rf, ff, callback, closure);
474 StepDiagBackward(board, flags, rf, ff, callback, closure);
478 Wazir (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
480 StepVertical(board, flags, rf, ff, callback, closure);
481 StepSideways(board, flags, rf, ff, callback, closure);
485 Knight (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
488 for (i = -1; i <= 1; i += 2)
489 for (j = -1; j <= 1; j += 2)
490 for (s = 1; s <= 2; s++) {
493 if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
494 && ( gameInfo.variant != VariantXiangqi || board[rf+i*(s-1)][ff+j*(2-s)] == EmptySquare)
495 && !SameColor(board[rf][ff], board[rt][ft]))
496 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
500 /* Call callback once for each pseudo-legal move in the given
501 position, except castling moves. A move is pseudo-legal if it is
502 legal, or if it would be legal except that it leaves the king in
503 check. In the arguments, epfile is EP_NONE if the previous move
504 was not a double pawn push, or the file 0..7 if it was, or
505 EP_UNKNOWN if we don't know and want to allow all e.p. captures.
506 Promotion moves generated are to Queen only.
509 GenPseudoLegal (Board board, int flags, MoveCallback callback, VOIDSTAR closure, ChessSquare filter)
510 // speed: only do moves with this piece type
513 int i, j, d, s, fs, rs, rt, ft, m;
514 int epfile = (signed char)board[EP_STATUS]; // [HGM] gamestate: extract ep status from board
515 int promoRank = gameInfo.variant == VariantMakruk || gameInfo.variant == VariantGrand || gameInfo.variant == VariantChuChess ? 3 : 1;
517 for (rf = 0; rf < BOARD_HEIGHT; rf++)
518 for (ff = BOARD_LEFT; ff < BOARD_RGHT; ff++) {
521 if(board[rf][ff] == EmptySquare) continue;
522 if ((flags & F_WHITE_ON_MOVE) != (board[rf][ff] < BlackPawn)) continue; // [HGM] speed: wrong color
523 m = 0; piece = board[rf][ff];
524 if(PieceToChar(piece) == '~')
525 piece = (ChessSquare) ( DEMOTED piece );
526 if(filter != EmptySquare && piece != filter) continue;
527 if(pieceDesc[piece]) { MovesFromString(board, flags, ff, rf, pieceDesc[piece], callback, closure); continue; } // [HGM] gen
528 if(IS_SHOGI(gameInfo.variant))
529 piece = (ChessSquare) ( SHOGI piece );
531 switch ((int)piece) {
532 /* case EmptySquare: [HGM] this is nonsense, and conflicts with Shogi cases */
534 /* can't happen ([HGM] except for faries...) */
538 if(gameInfo.variant == VariantXiangqi) {
539 /* [HGM] capture and move straight ahead in Xiangqi */
540 if (rf < BOARD_HEIGHT-1 &&
541 !SameColor(board[rf][ff], board[rf + 1][ff]) ) {
542 callback(board, flags, NormalMove,
543 rf, ff, rf + 1, ff, closure);
545 /* and move sideways when across the river */
546 for (s = -1; s <= 1; s += 2) {
547 if (rf >= BOARD_HEIGHT>>1 &&
548 ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
549 !WhitePiece(board[rf][ff+s]) ) {
550 callback(board, flags, NormalMove,
551 rf, ff, rf, ff+s, closure);
556 if (rf < BOARD_HEIGHT-1 && board[rf + 1][ff] == EmptySquare) {
557 callback(board, flags,
558 rf >= BOARD_HEIGHT-1-promoRank ? WhitePromotion : NormalMove,
559 rf, ff, rf + 1, ff, closure);
561 if (rf <= (BOARD_HEIGHT>>1)-3 && board[rf+1][ff] == EmptySquare && // [HGM] grand: also on 3rd rank on 10-board
562 gameInfo.variant != VariantShatranj && /* [HGM] */
563 gameInfo.variant != VariantCourier && /* [HGM] */
564 board[rf+2][ff] == EmptySquare ) {
565 callback(board, flags, NormalMove,
566 rf, ff, rf+2, ff, closure);
568 for (s = -1; s <= 1; s += 2) {
569 if (rf < BOARD_HEIGHT-1 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
570 ((flags & F_KRIEGSPIEL_CAPTURE) ||
571 BlackPiece(board[rf + 1][ff + s]))) {
572 callback(board, flags,
573 rf >= BOARD_HEIGHT-1-promoRank ? WhitePromotion : NormalMove,
574 rf, ff, rf + 1, ff + s, closure);
576 if (rf >= BOARD_HEIGHT+1>>1) {// [HGM] grand: 4th & 5th rank on 10-board
577 if (ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
578 (epfile == ff + s || epfile == EP_UNKNOWN) && rf < BOARD_HEIGHT-3 &&
579 board[rf][ff + s] == BlackPawn &&
580 board[rf+1][ff + s] == EmptySquare) {
581 callback(board, flags, WhiteCapturesEnPassant,
582 rf, ff, rf+1, ff + s, closure);
589 if(gameInfo.variant == VariantXiangqi) {
590 /* [HGM] capture straight ahead in Xiangqi */
591 if (rf > 0 && !SameColor(board[rf][ff], board[rf - 1][ff]) ) {
592 callback(board, flags, NormalMove,
593 rf, ff, rf - 1, ff, closure);
595 /* and move sideways when across the river */
596 for (s = -1; s <= 1; s += 2) {
597 if (rf < BOARD_HEIGHT>>1 &&
598 ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
599 !BlackPiece(board[rf][ff+s]) ) {
600 callback(board, flags, NormalMove,
601 rf, ff, rf, ff+s, closure);
606 if (rf > 0 && board[rf - 1][ff] == EmptySquare) {
607 callback(board, flags,
608 rf <= promoRank ? BlackPromotion : NormalMove,
609 rf, ff, rf - 1, ff, closure);
611 if (rf >= (BOARD_HEIGHT+1>>1)+2 && board[rf-1][ff] == EmptySquare && // [HGM] grand
612 gameInfo.variant != VariantShatranj && /* [HGM] */
613 gameInfo.variant != VariantCourier && /* [HGM] */
614 board[rf-2][ff] == EmptySquare) {
615 callback(board, flags, NormalMove,
616 rf, ff, rf-2, ff, closure);
618 for (s = -1; s <= 1; s += 2) {
619 if (rf > 0 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
620 ((flags & F_KRIEGSPIEL_CAPTURE) ||
621 WhitePiece(board[rf - 1][ff + s]))) {
622 callback(board, flags,
623 rf <= promoRank ? BlackPromotion : NormalMove,
624 rf, ff, rf - 1, ff + s, closure);
626 if (rf < BOARD_HEIGHT>>1) {
627 if (ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
628 (epfile == ff + s || epfile == EP_UNKNOWN) && rf > 2 &&
629 board[rf][ff + s] == WhitePawn &&
630 board[rf-1][ff + s] == EmptySquare) {
631 callback(board, flags, BlackCapturesEnPassant,
632 rf, ff, rf-1, ff + s, closure);
642 for (i = -1; i <= 1; i += 2)
643 for (j = -1; j <= 1; j += 2)
644 for (s = 1; s <= 2; s++) {
647 if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
648 && ( gameInfo.variant != VariantXiangqi || board[rf+i*(s-1)][ff+j*(2-s)] == EmptySquare)
649 && !SameColor(board[rf][ff], board[rt][ft]))
650 callback(board, flags, NormalMove,
651 rf, ff, rt, ft, closure);
655 case SHOGI WhiteKnight:
656 for (s = -1; s <= 1; s += 2) {
657 if (rf < BOARD_HEIGHT-2 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
658 !SameColor(board[rf][ff], board[rf + 2][ff + s])) {
659 callback(board, flags, NormalMove,
660 rf, ff, rf + 2, ff + s, closure);
665 case SHOGI BlackKnight:
666 for (s = -1; s <= 1; s += 2) {
667 if (rf > 1 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
668 !SameColor(board[rf][ff], board[rf - 2][ff + s])) {
669 callback(board, flags, NormalMove,
670 rf, ff, rf - 2, ff + s, closure);
677 for (d = 0; d <= 1; d++)
678 for (s = -1; s <= 1; s += 2) {
681 rt = rf + (i * s) * d;
682 ft = ff + (i * s) * (1 - d);
683 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
684 if (m == 0 && board[rt][ft] == EmptySquare)
685 callback(board, flags, NormalMove,
686 rf, ff, rt, ft, closure);
687 if (m == 1 && board[rt][ft] != EmptySquare &&
688 !SameColor(board[rf][ff], board[rt][ft]) )
689 callback(board, flags, NormalMove,
690 rf, ff, rt, ft, closure);
691 if (board[rt][ft] != EmptySquare && m++) break;
696 /* Gold General (and all its promoted versions) . First do the */
697 /* diagonal forward steps, then proceed as normal Wazir */
698 case SHOGI (PROMOTED WhitePawn):
699 if(gameInfo.variant == VariantShogi) goto WhiteGold;
700 case SHOGI (PROMOTED BlackPawn):
701 if(gameInfo.variant == VariantShogi) goto BlackGold;
702 SlideVertical(board, flags, rf, ff, callback, closure);
705 case SHOGI (PROMOTED WhiteKnight):
706 if(gameInfo.variant == VariantShogi) goto WhiteGold;
707 case SHOGI BlackDrunk:
708 case SHOGI BlackAlfil:
709 Ferz(board, flags, rf, ff, callback, closure);
710 StepSideways(board, flags, rf, ff, callback, closure);
711 StepBackward(board, flags, rf, ff, callback, closure);
714 case SHOGI (PROMOTED BlackKnight):
715 if(gameInfo.variant == VariantShogi) goto BlackGold;
716 case SHOGI WhiteDrunk:
717 case SHOGI WhiteAlfil:
718 Ferz(board, flags, rf, ff, callback, closure);
719 StepSideways(board, flags, rf, ff, callback, closure);
720 StepForward(board, flags, rf, ff, callback, closure);
724 case SHOGI WhiteStag:
725 case SHOGI BlackStag:
726 if(gameInfo.variant == VariantShogi) goto BlackGold;
727 SlideVertical(board, flags, rf, ff, callback, closure);
728 Ferz(board, flags, rf, ff, callback, closure);
729 StepSideways(board, flags, rf, ff, callback, closure);
732 case SHOGI (PROMOTED WhiteQueen):
733 case SHOGI WhiteTokin:
734 case SHOGI WhiteWazir:
736 StepDiagForward(board, flags, rf, ff, callback, closure);
737 Wazir(board, flags, rf, ff, callback, closure);
740 case SHOGI (PROMOTED BlackQueen):
741 case SHOGI BlackTokin:
742 case SHOGI BlackWazir:
744 StepDiagBackward(board, flags, rf, ff, callback, closure);
745 Wazir(board, flags, rf, ff, callback, closure);
750 Wazir(board, flags, rf, ff, callback, closure);
753 case SHOGI WhiteMarshall:
754 case SHOGI BlackMarshall:
755 Ferz(board, flags, rf, ff, callback, closure);
756 for (d = 0; d <= 1; d++)
757 for (s = -2; s <= 2; s += 4) {
759 ft = ff + s * (1 - d);
760 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) continue;
761 if (!SameColor(board[rf][ff], board[rt][ft]) )
762 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
766 case SHOGI WhiteAngel:
767 case SHOGI BlackAngel:
768 Wazir(board, flags, rf, ff, callback, closure);
772 /* [HGM] support Shatranj pieces */
773 for (rs = -1; rs <= 1; rs += 2)
774 for (fs = -1; fs <= 1; fs += 2) {
777 if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
778 && ( gameInfo.variant != VariantXiangqi ||
779 board[rf+rs][ff+fs] == EmptySquare && (2*rf < BOARD_HEIGHT) == (2*rt < BOARD_HEIGHT) )
781 && !SameColor(board[rf][ff], board[rt][ft]))
782 callback(board, flags, NormalMove,
783 rf, ff, rt, ft, closure);
784 if(gameInfo.variant == VariantShatranj || gameInfo.variant == VariantCourier ||
785 gameInfo.variant == VariantChu || gameInfo.variant == VariantXiangqi) continue; // classical Alfil
786 rt = rf + rs; // in unknown variant we assume Modern Elephant, which can also do one step
788 if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
789 && !SameColor(board[rf][ff], board[rt][ft]))
790 callback(board, flags, NormalMove,
791 rf, ff, rt, ft, closure);
793 if(gameInfo.variant == VariantSpartan)
794 for(fs = -1; fs <= 1; fs += 2) {
796 if (!(ft < BOARD_LEFT || ft >= BOARD_RGHT) && board[rf][ft] == EmptySquare)
797 callback(board, flags, NormalMove, rf, ff, rf, ft, closure);
801 /* Make Dragon-Horse also do Dababba moves outside Shogi, for better disambiguation in variant Fairy */
804 if(gameInfo.variant == VariantChuChess) goto DragonHorse;
805 for (d = 0; d <= 1; d++) // Dababba moves that Rook cannot do
806 for (s = -2; s <= 2; s += 4) {
808 ft = ff + s * (1 - d);
809 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) continue;
810 if (SameColor(board[rf][ff], board[rt][ft])) continue;
811 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
814 /* Shogi Dragon Horse has to continue with Wazir after Bishop */
815 case SHOGI WhiteCardinal:
816 case SHOGI BlackCardinal:
817 case SHOGI WhitePCardinal:
818 case SHOGI BlackPCardinal:
820 Bishop(board, flags, rf, ff, callback, closure);
821 Wazir(board, flags, rf, ff, callback, closure);
824 /* Capablanca Archbishop continues as Knight */
827 Knight(board, flags, rf, ff, callback, closure);
829 /* Shogi Bishops are ordinary Bishops */
830 case SHOGI WhiteBishop:
831 case SHOGI BlackBishop:
832 case SHOGI WhitePBishop:
833 case SHOGI BlackPBishop:
836 Bishop(board, flags, rf, ff, callback, closure);
839 /* Shogi Lance is unlike anything, and asymmetric at that */
840 case SHOGI WhiteQueen:
841 if(gameInfo.variant == VariantChu) goto doQueen;
845 if (rt >= BOARD_HEIGHT) break;
846 if (SameColor(board[rf][ff], board[rt][ft])) break;
847 callback(board, flags, NormalMove,
848 rf, ff, rt, ft, closure);
849 if (board[rt][ft] != EmptySquare) break;
853 case SHOGI BlackQueen:
854 if(gameInfo.variant == VariantChu) goto doQueen;
859 if (SameColor(board[rf][ff], board[rt][ft])) break;
860 callback(board, flags, NormalMove,
861 rf, ff, rt, ft, closure);
862 if (board[rt][ft] != EmptySquare) break;
866 /* Make Dragon-King Dababba & Rook-like outside Shogi, for better disambiguation in variant Fairy */
869 if(gameInfo.variant == VariantChuChess) goto DragonKing;
870 for (d = 0; d <= 1; d++) // Dababba moves that Rook cannot do
871 for (s = -2; s <= 2; s += 4) {
873 ft = ff + s * (1 - d);
874 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) continue;
875 if (board[rf+rt>>1][ff+ft>>1] == EmptySquare && gameInfo.variant != VariantSpartan) continue;
876 if (SameColor(board[rf][ff], board[rt][ft])) continue;
877 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
879 if(gameInfo.variant == VariantSpartan) // in Spartan Chess restrict range to modern Dababba
880 Wazir(board, flags, rf, ff, callback, closure);
882 Rook(board, flags, rf, ff, callback, closure);
885 /* Shogi Dragon King has to continue as Ferz after Rook moves */
886 case SHOGI WhiteDragon:
887 case SHOGI BlackDragon:
888 case SHOGI WhitePDragon:
889 case SHOGI BlackPDragon:
891 Rook(board, flags, rf, ff, callback, closure);
892 Ferz(board, flags, rf, ff, callback, closure);
896 /* Capablanca Chancellor sets flag to continue as Knight */
899 Rook(board, flags, rf, ff, callback, closure);
900 if(gameInfo.variant == VariantSpartan) // in Spartan Chess Chancellor is used for Dragon King.
901 Ferz(board, flags, rf, ff, callback, closure);
903 Knight(board, flags, rf, ff, callback, closure);
906 /* Shogi Rooks are ordinary Rooks */
907 case SHOGI WhiteRook:
908 case SHOGI BlackRook:
909 case SHOGI WhitePRook:
910 case SHOGI BlackPRook:
913 Rook(board, flags, rf, ff, callback, closure);
918 case SHOGI WhiteMother:
919 case SHOGI BlackMother:
921 Rook(board, flags, rf, ff, callback, closure);
922 Bishop(board, flags, rf, ff, callback, closure);
925 case SHOGI WhitePawn:
926 StepForward(board, flags, rf, ff, callback, closure);
929 case SHOGI BlackPawn:
930 StepBackward(board, flags, rf, ff, callback, closure);
934 if(gameInfo.variant != VariantMakruk && gameInfo.variant != VariantASEAN) goto commoner;
935 case SHOGI WhiteFerz:
936 Ferz(board, flags, rf, ff, callback, closure);
937 StepForward(board, flags, rf, ff, callback, closure);
941 if(gameInfo.variant != VariantMakruk && gameInfo.variant != VariantASEAN) goto commoner;
942 case SHOGI BlackFerz:
943 StepBackward(board, flags, rf, ff, callback, closure);
947 /* [HGM] support Shatranj pieces */
948 Ferz(board, flags, rf, ff, callback, closure);
953 Knight(board, flags, rf, ff, callback, closure); // [HGM] superchess: use for Centaur
956 case SHOGI WhiteMonarch:
957 case SHOGI BlackMonarch:
958 case SHOGI WhiteKing:
959 case SHOGI BlackKing:
962 Ferz(board, flags, rf, ff, callback, closure);
963 Wazir(board, flags, rf, ff, callback, closure);
966 case WhiteNightrider:
967 case BlackNightrider:
968 for (i = -1; i <= 1; i += 2)
969 for (j = -1; j <= 1; j += 2)
970 for (s = 1; s <= 2; s++) { int k;
974 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
975 if (SameColor(board[rf][ff], board[rt][ft])) break;
976 callback(board, flags, NormalMove,
977 rf, ff, rt, ft, closure);
978 if (board[rt][ft] != EmptySquare) break;
984 Bishop(board, flags, rf, ff, callback, closure);
985 Rook(board, flags, rf, ff, callback, closure);
986 Knight(board, flags, rf, ff, callback, closure);
989 // Use Lance as Berolina / Spartan Pawn.
991 if(gameInfo.variant == VariantSuper) goto Amazon;
992 if (rf < BOARD_HEIGHT-1 && BlackPiece(board[rf + 1][ff]))
993 callback(board, flags,
994 rf >= BOARD_HEIGHT-1-promoRank ? WhitePromotion : NormalMove,
995 rf, ff, rf + 1, ff, closure);
996 for (s = -1; s <= 1; s += 2) {
997 if (rf < BOARD_HEIGHT-1 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT && board[rf + 1][ff + s] == EmptySquare)
998 callback(board, flags,
999 rf >= BOARD_HEIGHT-1-promoRank ? WhitePromotion : NormalMove,
1000 rf, ff, rf + 1, ff + s, closure);
1001 if (rf == 1 && ff + 2*s >= BOARD_LEFT && ff + 2*s < BOARD_RGHT && board[3][ff + 2*s] == EmptySquare )
1002 callback(board, flags, NormalMove, rf, ff, 3, ff + 2*s, closure);
1007 if(gameInfo.variant == VariantSuper) goto Amazon;
1008 if (rf > 0 && WhitePiece(board[rf - 1][ff]))
1009 callback(board, flags,
1010 rf <= promoRank ? BlackPromotion : NormalMove,
1011 rf, ff, rf - 1, ff, closure);
1012 for (s = -1; s <= 1; s += 2) {
1013 if (rf > 0 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT && board[rf - 1][ff + s] == EmptySquare)
1014 callback(board, flags,
1015 rf <= promoRank ? BlackPromotion : NormalMove,
1016 rf, ff, rf - 1, ff + s, closure);
1017 if (rf == BOARD_HEIGHT-2 && ff + 2*s >= BOARD_LEFT && ff + 2*s < BOARD_RGHT && board[rf-2][ff + 2*s] == EmptySquare )
1018 callback(board, flags, NormalMove, rf, ff, rf-2, ff + 2*s, closure);
1022 case SHOGI WhiteNothing:
1023 case SHOGI BlackNothing:
1024 case SHOGI WhiteLion:
1025 case SHOGI BlackLion:
1028 for(rt = rf - 2; rt <= rf + 2; rt++) for(ft = ff - 2; ft <= ff + 2; ft++) {
1029 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) continue;
1030 if (!(ff == ft && rf == rt) && SameColor(board[rf][ff], board[rt][ft])) continue;
1031 callback(board, flags, (rt-rf)*(rt-rf) + (ff-ft)*(ff-ft) < 3 && board[rt][ft] != EmptySquare ? FirstLeg : NormalMove,
1032 rf, ff, rt, ft, closure);
1036 case SHOGI WhiteFalcon:
1037 case SHOGI BlackFalcon:
1038 case SHOGI WhitePDagger:
1039 case SHOGI BlackPDagger:
1040 SlideSideways(board, flags, rf, ff, callback, closure);
1041 StepVertical(board, flags, rf, ff, callback, closure);
1044 case SHOGI WhiteCobra:
1045 case SHOGI BlackCobra:
1046 StepVertical(board, flags, rf, ff, callback, closure);
1049 case SHOGI (PROMOTED WhiteFerz):
1050 if(gameInfo.variant == VariantShogi) goto WhiteGold;
1051 case SHOGI (PROMOTED BlackFerz):
1052 if(gameInfo.variant == VariantShogi) goto BlackGold;
1053 case SHOGI WhitePSword:
1054 case SHOGI BlackPSword:
1055 SlideVertical(board, flags, rf, ff, callback, closure);
1056 StepSideways(board, flags, rf, ff, callback, closure);
1059 case SHOGI WhiteUnicorn:
1060 case SHOGI BlackUnicorn:
1061 Ferz(board, flags, rf, ff, callback, closure);
1062 StepVertical(board, flags, rf, ff, callback, closure);
1065 case SHOGI WhiteMan:
1066 StepDiagForward(board, flags, rf, ff, callback, closure);
1067 StepVertical(board, flags, rf, ff, callback, closure);
1070 case SHOGI BlackMan:
1071 StepDiagBackward(board, flags, rf, ff, callback, closure);
1072 StepVertical(board, flags, rf, ff, callback, closure);
1075 case SHOGI WhiteHCrown:
1076 case SHOGI BlackHCrown:
1077 Bishop(board, flags, rf, ff, callback, closure);
1078 SlideSideways(board, flags, rf, ff, callback, closure);
1081 case SHOGI WhiteCrown:
1082 case SHOGI BlackCrown:
1083 Bishop(board, flags, rf, ff, callback, closure);
1084 SlideVertical(board, flags, rf, ff, callback, closure);
1087 case SHOGI WhiteHorned:
1088 Sting(board, flags, rf, ff, 1, 0, callback, closure);
1089 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1090 if(killX >= 0) break;
1091 Bishop(board, flags, rf, ff, callback, closure);
1092 SlideSideways(board, flags, rf, ff, callback, closure);
1093 SlideBackward(board, flags, rf, ff, callback, closure);
1096 case SHOGI BlackHorned:
1097 Sting(board, flags, rf, ff, -1, 0, callback, closure);
1098 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1099 if(killX >= 0) break;
1100 Bishop(board, flags, rf, ff, callback, closure);
1101 SlideSideways(board, flags, rf, ff, callback, closure);
1102 SlideForward(board, flags, rf, ff, callback, closure);
1105 case SHOGI WhiteEagle:
1106 Sting(board, flags, rf, ff, 1, 1, callback, closure);
1107 Sting(board, flags, rf, ff, 1, -1, callback, closure);
1108 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1109 if(killX >= 0) break;
1110 Rook(board, flags, rf, ff, callback, closure);
1111 SlideDiagBackward(board, flags, rf, ff, callback, closure);
1114 case SHOGI BlackEagle:
1115 Sting(board, flags, rf, ff, -1, 1, callback, closure);
1116 Sting(board, flags, rf, ff, -1, -1, callback, closure);
1117 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1118 if(killX >= 0) break;
1119 Rook(board, flags, rf, ff, callback, closure);
1120 SlideDiagForward(board, flags, rf, ff, callback, closure);
1123 case SHOGI WhiteDolphin:
1124 case SHOGI BlackHorse:
1125 SlideDiagBackward(board, flags, rf, ff, callback, closure);
1126 SlideVertical(board, flags, rf, ff, callback, closure);
1129 case SHOGI BlackDolphin:
1130 case SHOGI WhiteHorse:
1131 SlideDiagForward(board, flags, rf, ff, callback, closure);
1132 SlideVertical(board, flags, rf, ff, callback, closure);
1135 case SHOGI WhiteLance:
1136 SlideForward(board, flags, rf, ff, callback, closure);
1139 case SHOGI BlackLance:
1140 SlideBackward(board, flags, rf, ff, callback, closure);
1143 case WhiteFalcon: // [HGM] wild: for wildcards, self-capture symbolizes move to anywhere
1147 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1160 int rFilter, fFilter; // [HGM] speed: sorry, but I get a bit tired of this closure madness
1161 Board xqCheckers, nullBoard;
1163 extern void GenLegalCallback P((Board board, int flags, ChessMove kind,
1164 int rf, int ff, int rt, int ft,
1168 GenLegalCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1170 register GenLegalClosure *cl = (GenLegalClosure *) closure;
1172 if(rFilter >= 0 && rFilter != rt || fFilter >= 0 && fFilter != ft) return; // [HGM] speed: ignore moves with wrong to-square
1174 if (board[EP_STATUS] == EP_IRON_LION && (board[rt][ft] == WhiteLion || board[rt][ft] == BlackLion)) return; //[HGM] lion
1176 if (!(flags & F_IGNORE_CHECK) ) {
1177 int check, promo = (gameInfo.variant == VariantSpartan && kind == BlackPromotion);
1180 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++)
1181 kings += (board[r][f] == BlackKing);
1185 board[rf][ff] = BlackKing; // [HGM] spartan: promote to King before check-test
1187 check = CheckTest(board, flags, rf, ff, rt, ft,
1188 kind == WhiteCapturesEnPassant ||
1189 kind == BlackCapturesEnPassant);
1190 if(promo) board[rf][ff] = BlackLance;
1193 if (flags & F_ATOMIC_CAPTURE) {
1194 if (board[rt][ft] != EmptySquare ||
1195 kind == WhiteCapturesEnPassant || kind == BlackCapturesEnPassant) {
1197 ChessSquare king = (flags & F_WHITE_ON_MOVE) ? WhiteKing : BlackKing;
1198 if (board[rf][ff] == king) return;
1199 for (r = rt-1; r <= rt+1; r++) {
1200 for (f = ft-1; f <= ft+1; f++) {
1201 if (r >= 0 && r < BOARD_HEIGHT && f >= BOARD_LEFT && f < BOARD_RGHT &&
1202 board[r][f] == king) return;
1207 cl->cb(board, flags, kind, rf, ff, rt, ft, cl->cl);
1214 int captures; // [HGM] losers
1215 } LegalityTestClosure;
1218 /* Like GenPseudoLegal, but (1) include castling moves, (2) unless
1219 F_IGNORE_CHECK is set in the flags, omit moves that would leave the
1220 king in check, and (3) if F_ATOMIC_CAPTURE is set in the flags, omit
1221 moves that would destroy your own king. The CASTLE_OK flags are
1222 true if castling is not yet ruled out by a move of the king or
1223 rook. Return TRUE if the player on move is currently in check and
1224 F_IGNORE_CHECK is not set. [HGM] add castlingRights parameter */
1226 GenLegal (Board board, int flags, MoveCallback callback, VOIDSTAR closure, ChessSquare filter)
1229 int ff, ft, k, left, right, swap;
1230 int ignoreCheck = (flags & F_IGNORE_CHECK) != 0;
1231 ChessSquare wKing = WhiteKing, bKing = BlackKing, *castlingRights = board[CASTLING];
1232 int inCheck = !ignoreCheck && CheckTest(board, flags, -1, -1, -1, -1, FALSE); // kludge alert: this would mark pre-existing checkers if status==1
1237 xqCheckers[EP_STATUS] *= 2; // quasi: if previous CheckTest has been marking, we now set flag for suspending same checkers
1238 if(filter == EmptySquare) rFilter = fFilter = -1; // [HGM] speed: do not filter on square if we do not filter on piece
1239 GenPseudoLegal(board, flags, GenLegalCallback, (VOIDSTAR) &cl, filter);
1241 if (inCheck) return TRUE;
1243 /* Generate castling moves */
1244 if(gameInfo.variant == VariantKnightmate) { /* [HGM] Knightmate */
1245 wKing = WhiteUnicorn; bKing = BlackUnicorn;
1248 p = (flags & F_WHITE_ON_MOVE ? pieceDesc[wKing] : pieceDesc[bKing]);
1249 if(p && strchr(p, 'O')) return FALSE; // [HGM] gen: castlings were already generated from string
1251 for (ff = BOARD_WIDTH>>1; ff >= (BOARD_WIDTH-1)>>1; ff-- /*ics wild 1*/) {
1252 if ((flags & F_WHITE_ON_MOVE) &&
1253 (flags & F_WHITE_KCASTLE_OK) &&
1254 board[0][ff] == wKing &&
1255 board[0][ff + 1] == EmptySquare &&
1256 board[0][ff + 2] == EmptySquare &&
1257 board[0][BOARD_RGHT-3] == EmptySquare &&
1258 board[0][BOARD_RGHT-2] == EmptySquare &&
1259 board[0][BOARD_RGHT-1] == WhiteRook &&
1260 castlingRights[0] != NoRights && /* [HGM] check rights */
1261 ( castlingRights[2] == ff || castlingRights[6] == ff ) &&
1263 (!CheckTest(board, flags, 0, ff, 0, ff + 1, FALSE) &&
1264 !CheckTest(board, flags, 0, ff, 0, BOARD_RGHT-3, FALSE) &&
1265 (gameInfo.variant != VariantJanus || !CheckTest(board, flags, 0, ff, 0, BOARD_RGHT-2, FALSE)) &&
1266 !CheckTest(board, flags, 0, ff, 0, ff + 2, FALSE)))) {
1268 callback(board, flags,
1269 ff==BOARD_WIDTH>>1 ? WhiteKingSideCastle : WhiteKingSideCastleWild,
1270 0, ff, 0, ff + ((gameInfo.boardWidth+2)>>2) + (gameInfo.variant == VariantJanus), closure);
1272 if ((flags & F_WHITE_ON_MOVE) &&
1273 (flags & F_WHITE_QCASTLE_OK) &&
1274 board[0][ff] == wKing &&
1275 board[0][ff - 1] == EmptySquare &&
1276 board[0][ff - 2] == EmptySquare &&
1277 board[0][BOARD_LEFT+2] == EmptySquare &&
1278 board[0][BOARD_LEFT+1] == EmptySquare &&
1279 board[0][BOARD_LEFT+0] == WhiteRook &&
1280 castlingRights[1] != NoRights && /* [HGM] check rights */
1281 ( castlingRights[2] == ff || castlingRights[6] == ff ) &&
1283 (!CheckTest(board, flags, 0, ff, 0, ff - 1, FALSE) &&
1284 !CheckTest(board, flags, 0, ff, 0, BOARD_LEFT+3, FALSE) &&
1285 !CheckTest(board, flags, 0, ff, 0, ff - 2, FALSE)))) {
1287 callback(board, flags,
1288 ff==BOARD_WIDTH>>1 ? WhiteQueenSideCastle : WhiteQueenSideCastleWild,
1289 0, ff, 0, ff - ((gameInfo.boardWidth+2)>>2), closure);
1291 if (!(flags & F_WHITE_ON_MOVE) &&
1292 (flags & F_BLACK_KCASTLE_OK) &&
1293 board[BOARD_HEIGHT-1][ff] == bKing &&
1294 board[BOARD_HEIGHT-1][ff + 1] == EmptySquare &&
1295 board[BOARD_HEIGHT-1][ff + 2] == EmptySquare &&
1296 board[BOARD_HEIGHT-1][BOARD_RGHT-3] == EmptySquare &&
1297 board[BOARD_HEIGHT-1][BOARD_RGHT-2] == EmptySquare &&
1298 board[BOARD_HEIGHT-1][BOARD_RGHT-1] == BlackRook &&
1299 castlingRights[3] != NoRights && /* [HGM] check rights */
1300 ( castlingRights[5] == ff || castlingRights[7] == ff ) &&
1302 (!CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff + 1, FALSE) &&
1303 !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, BOARD_RGHT-3, FALSE) &&
1304 (gameInfo.variant != VariantJanus || !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, BOARD_RGHT-2, FALSE)) &&
1305 !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff + 2, FALSE)))) {
1307 callback(board, flags,
1308 ff==BOARD_WIDTH>>1 ? BlackKingSideCastle : BlackKingSideCastleWild,
1309 BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff + ((gameInfo.boardWidth+2)>>2) + (gameInfo.variant == VariantJanus), closure);
1311 if (!(flags & F_WHITE_ON_MOVE) &&
1312 (flags & F_BLACK_QCASTLE_OK) &&
1313 board[BOARD_HEIGHT-1][ff] == bKing &&
1314 board[BOARD_HEIGHT-1][ff - 1] == EmptySquare &&
1315 board[BOARD_HEIGHT-1][ff - 2] == EmptySquare &&
1316 board[BOARD_HEIGHT-1][BOARD_LEFT+2] == EmptySquare &&
1317 board[BOARD_HEIGHT-1][BOARD_LEFT+1] == EmptySquare &&
1318 board[BOARD_HEIGHT-1][BOARD_LEFT+0] == BlackRook &&
1319 castlingRights[4] != NoRights && /* [HGM] check rights */
1320 ( castlingRights[5] == ff || castlingRights[7] == ff ) &&
1322 (!CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff - 1, FALSE) &&
1323 !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, BOARD_LEFT+3, FALSE) &&
1324 !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff - 2, FALSE)))) {
1326 callback(board, flags,
1327 ff==BOARD_WIDTH>>1 ? BlackQueenSideCastle : BlackQueenSideCastleWild,
1328 BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff - ((gameInfo.boardWidth+2)>>2), closure);
1332 if((swap = gameInfo.variant == VariantSChess) || flags & F_FRC_TYPE_CASTLING) {
1334 /* generate all potential FRC castling moves (KxR), ignoring flags */
1335 /* [HGM] test if the Rooks we find have castling rights */
1336 /* In S-Chess we generate RxK for allowed castlings, for gating at Rook square */
1339 if ((flags & F_WHITE_ON_MOVE) != 0) {
1340 ff = castlingRights[2]; /* King file if we have any rights */
1341 if(ff != NoRights && board[0][ff] == WhiteKing) {
1342 if (appData.debugMode) {
1343 fprintf(debugFP, "FRC castling, %d %d %d %d %d %d\n",
1344 castlingRights[0],castlingRights[1],ff,castlingRights[3],castlingRights[4],castlingRights[5]);
1346 ft = castlingRights[0]; /* Rook file if we have H-side rights */
1348 right = BOARD_RGHT-2;
1349 if(ff == BOARD_RGHT-2) left = right = ff-1; /* special case */
1350 for(k=left; k<=right && ft != NoRights; k++) /* first test if blocked */
1351 if(k != ft && board[0][k] != EmptySquare) ft = NoRights;
1352 for(k=left; k<right && ft != NoRights; k++) /* then if not checked */
1353 if(!ignoreCheck && CheckTest(board, flags, 0, ff, 0, k, FALSE)) ft = NoRights;
1354 if(ft != NoRights && board[0][ft] == WhiteRook) {
1355 if(flags & F_FRC_TYPE_CASTLING) callback(board, flags, WhiteHSideCastleFR, 0, ff, 0, ft, closure);
1356 if(swap) callback(board, flags, WhiteHSideCastleFR, 0, ft, 0, ff, closure);
1359 ft = castlingRights[1]; /* Rook file if we have A-side rights */
1360 left = BOARD_LEFT+2;
1362 if(ff <= BOARD_LEFT+2) { left = ff+1; right = BOARD_LEFT+3; }
1363 for(k=left; k<=right && ft != NoRights; k++) /* first test if blocked */
1364 if(k != ft && board[0][k] != EmptySquare) ft = NoRights;
1365 if(ft == 0 && ff != 1 && board[0][1] != EmptySquare) ft = NoRights; /* Rook can be blocked on b1 */
1366 if(ff > BOARD_LEFT+2)
1367 for(k=left+1; k<=right && ft != NoRights; k++) /* then if not checked */
1368 if(!ignoreCheck && CheckTest(board, flags, 0, ff, 0, k, FALSE)) ft = NoRights;
1369 if(ft != NoRights && board[0][ft] == WhiteRook) {
1370 if(flags & F_FRC_TYPE_CASTLING) callback(board, flags, WhiteASideCastleFR, 0, ff, 0, ft, closure);
1371 if(swap) callback(board, flags, WhiteASideCastleFR, 0, ft, 0, ff, closure);
1375 ff = castlingRights[5]; /* King file if we have any rights */
1376 if(ff != NoRights && board[BOARD_HEIGHT-1][ff] == BlackKing) {
1377 ft = castlingRights[3]; /* Rook file if we have H-side rights */
1379 right = BOARD_RGHT-2;
1380 if(ff == BOARD_RGHT-2) left = right = ff-1; /* special case */
1381 for(k=left; k<=right && ft != NoRights; k++) /* first test if blocked */
1382 if(k != ft && board[BOARD_HEIGHT-1][k] != EmptySquare) ft = NoRights;
1383 for(k=left; k<right && ft != NoRights; k++) /* then if not checked */
1384 if(!ignoreCheck && CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, k, FALSE)) ft = NoRights;
1385 if(ft != NoRights && board[BOARD_HEIGHT-1][ft] == BlackRook) {
1386 if(flags & F_FRC_TYPE_CASTLING) callback(board, flags, BlackHSideCastleFR, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ft, closure);
1387 if(swap) callback(board, flags, BlackHSideCastleFR, BOARD_HEIGHT-1, ft, BOARD_HEIGHT-1, ff, closure);
1390 ft = castlingRights[4]; /* Rook file if we have A-side rights */
1391 left = BOARD_LEFT+2;
1393 if(ff <= BOARD_LEFT+2) { left = ff+1; right = BOARD_LEFT+3; }
1394 for(k=left; k<=right && ft != NoRights; k++) /* first test if blocked */
1395 if(k != ft && board[BOARD_HEIGHT-1][k] != EmptySquare) ft = NoRights;
1396 if(ft == 0 && ff != 1 && board[BOARD_HEIGHT-1][1] != EmptySquare) ft = NoRights; /* Rook can be blocked on b8 */
1397 if(ff > BOARD_LEFT+2)
1398 for(k=left+1; k<=right && ft != NoRights; k++) /* then if not checked */
1399 if(!ignoreCheck && CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, k, FALSE)) ft = NoRights;
1400 if(ft != NoRights && board[BOARD_HEIGHT-1][ft] == BlackRook) {
1401 if(flags & F_FRC_TYPE_CASTLING) callback(board, flags, BlackASideCastleFR, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ft, closure);
1402 if(swap) callback(board, flags, BlackASideCastleFR, BOARD_HEIGHT-1, ft, BOARD_HEIGHT-1, ff, closure);
1419 extern void CheckTestCallback P((Board board, int flags, ChessMove kind,
1420 int rf, int ff, int rt, int ft,
1425 CheckTestCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1427 register CheckTestClosure *cl = (CheckTestClosure *) closure;
1429 if (rt == cl->rking && ft == cl->fking) {
1430 if(xqCheckers[EP_STATUS] >= 2 && xqCheckers[rf][ff]) return; // checker is piece with suspended checking power
1432 xqCheckers[rf][ff] = xqCheckers[EP_STATUS] & 1; // remember who is checking (if status == 1)
1434 if( board[EP_STATUS] == EP_ROYAL_LION && (board[rt][ft] == WhiteLion || board[rt][ft] == BlackLion)
1435 && (gameInfo.variant != VariantLion || board[rf][ff] != WhiteKing && board[rf][ff] != BlackKing) )
1436 cl->check++; // [HGM] lion: forbidden counterstrike against Lion equated to putting yourself in check
1440 /* If the player on move were to move from (rf, ff) to (rt, ft), would
1441 he leave himself in check? Or if rf == -1, is the player on move
1442 in check now? enPassant must be TRUE if the indicated move is an
1443 e.p. capture. The possibility of castling out of a check along the
1444 back rank is not accounted for (i.e., we still return nonzero), as
1445 this is illegal anyway. Return value is the number of times the
1446 king is in check. */
1448 CheckTest (Board board, int flags, int rf, int ff, int rt, int ft, int enPassant)
1450 CheckTestClosure cl;
1451 ChessSquare king = flags & F_WHITE_ON_MOVE ? WhiteKing : BlackKing;
1452 ChessSquare captured = EmptySquare, ep=0, trampled=0;
1453 /* Suppress warnings on uninitialized variables */
1455 if(gameInfo.variant == VariantXiangqi)
1456 king = flags & F_WHITE_ON_MOVE ? WhiteWazir : BlackWazir;
1457 if(gameInfo.variant == VariantKnightmate)
1458 king = flags & F_WHITE_ON_MOVE ? WhiteUnicorn : BlackUnicorn;
1459 if(gameInfo.variant == VariantChu) { // strictly speaking this is not needed, as Chu officially has no check
1460 int r, f, k = king, royals=0, prince = flags & F_WHITE_ON_MOVE ? WhiteMonarch : BlackMonarch;
1461 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++) {
1462 if(board[r][f] == k || board[r][f] == prince) {
1463 if(++royals > 1) return FALSE; // no check if we have two royals (ignores double captureby Lion!)
1464 king = board[r][f]; // remember hich one we had
1471 captured = board[rf][ft];
1472 board[rf][ft] = EmptySquare;
1474 captured = board[rt][ft];
1475 if(killX >= 0) { trampled = board[killY][killX]; board[killY][killX] = EmptySquare; }
1477 if(rf == DROP_RANK) board[rt][ft] = ff; else { // [HGM] drop
1478 board[rt][ft] = board[rf][ff];
1479 board[rf][ff] = EmptySquare;
1481 ep = board[EP_STATUS];
1482 if( captured == WhiteLion || captured == BlackLion ) { // [HGM] lion: Chu Lion-capture rules
1483 ChessSquare victim = killX < 0 ? EmptySquare : trampled;
1484 if( (board[rt][ft] == WhiteLion || board[rt][ft] == BlackLion) && // capturer is Lion
1485 (ff - ft > 1 || ft - ff > 1 || rf - rt > 1 || rt - rf > 1) && // captures from a distance
1486 (victim == EmptySquare || victim == WhitePawn || victim == BlackPawn) ) // no or worthless 'bridge'
1487 board[EP_STATUS] = EP_ROYAL_LION; // on distant Lion x Lion victim must not be pseudo-legally protected
1491 /* For compatibility with ICS wild 9, we scan the board in the
1492 order a1, a2, a3, ... b1, b2, ..., h8 to find the first king,
1493 and we test only whether that one is in check. */
1494 for (cl.fking = BOARD_LEFT+0; cl.fking < BOARD_RGHT; cl.fking++)
1495 for (cl.rking = 0; cl.rking < BOARD_HEIGHT; cl.rking++) {
1496 if (board[cl.rking][cl.fking] == king) {
1498 if(gameInfo.variant == VariantXiangqi) {
1499 /* [HGM] In Xiangqi opposing Kings means check as well */
1501 dir = (king >= BlackPawn) ? -1 : 1;
1502 for( i=cl.rking+dir; i>=0 && i<BOARD_HEIGHT &&
1503 board[i][cl.fking] == EmptySquare; i+=dir );
1504 if(i>=0 && i<BOARD_HEIGHT &&
1505 board[i][cl.fking] == (dir>0 ? BlackWazir : WhiteWazir) )
1508 GenPseudoLegal(board, flags ^ F_WHITE_ON_MOVE, CheckTestCallback, (VOIDSTAR) &cl, EmptySquare);
1509 if(gameInfo.variant != VariantSpartan || cl.check == 0) // in Spartan Chess go on to test if other King is checked too
1510 goto undo_move; /* 2-level break */
1517 if(rf != DROP_RANK) // [HGM] drop
1518 board[rf][ff] = board[rt][ft];
1520 board[rf][ft] = captured;
1521 board[rt][ft] = EmptySquare;
1523 if(killX >= 0) board[killY][killX] = trampled;
1524 board[rt][ft] = captured;
1526 board[EP_STATUS] = ep;
1529 return cl.fking < BOARD_RGHT ? cl.check : 1000; // [HGM] atomic: return 1000 if we have no king
1533 HasLion (Board board, int flags)
1535 int lion = F_WHITE_ON_MOVE & flags ? WhiteLion : BlackLion;
1537 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++)
1538 if(board[r][f] == lion) return 1;
1543 LegalDrop (Board board, int flags, ChessSquare piece, int rt, int ft)
1544 { // [HGM] put drop legality testing in separate routine for clarity
1546 if(appData.debugMode) fprintf(debugFP, "LegalDrop: %d @ %d,%d)\n", piece, ft, rt);
1547 if(board[rt][ft] != EmptySquare) return ImpossibleMove; // must drop to empty square
1548 n = PieceToNumber(piece);
1549 if((gameInfo.holdingsWidth == 0 || (flags & F_WHITE_ON_MOVE ? board[n][BOARD_WIDTH-1] : board[BOARD_HEIGHT-1-n][0]) != piece)
1550 && gameInfo.variant != VariantBughouse) // in bughouse we don't check for availability, because ICS doesn't always tell us
1551 return ImpossibleMove; // piece not available
1552 if(gameInfo.variant == VariantShogi) { // in Shogi lots of drops are forbidden!
1553 if((piece == WhitePawn || piece == WhiteQueen) && rt == BOARD_HEIGHT-1 ||
1554 (piece == BlackPawn || piece == BlackQueen) && rt == 0 ||
1555 piece == WhiteKnight && rt > BOARD_HEIGHT-3 ||
1556 piece == BlackKnight && rt < 2 ) return IllegalMove; // e.g. where dropped piece has no moves
1557 if(piece == WhitePawn || piece == BlackPawn) {
1558 int r, max = 1 + (BOARD_HEIGHT == 7); // two Pawns per file in Tori!
1559 for(r=1; r<BOARD_HEIGHT-1; r++)
1560 if(!(max -= (board[r][ft] == piece))) return IllegalMove; // or there already is a Pawn in file
1561 // should still test if we mate with this Pawn
1563 } else if(gameInfo.variant == VariantSChess) { // only back-rank drops
1564 if (rt != (piece < BlackPawn ? 0 : BOARD_HEIGHT-1)) return IllegalMove;
1566 if( (piece == WhitePawn || piece == BlackPawn) &&
1567 (rt == 0 || rt == BOARD_HEIGHT -1 ) )
1568 return IllegalMove; /* no pawn drops on 1st/8th */
1570 if(appData.debugMode) fprintf(debugFP, "LegalDrop: %d @ %d,%d)\n", piece, ft, rt);
1571 if (!(flags & F_IGNORE_CHECK) &&
1572 CheckTest(board, flags, DROP_RANK, piece, rt, ft, FALSE) ) return IllegalMove;
1573 return flags & F_WHITE_ON_MOVE ? WhiteDrop : BlackDrop;
1576 extern void LegalityTestCallback P((Board board, int flags, ChessMove kind,
1577 int rf, int ff, int rt, int ft,
1581 LegalityTestCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1583 register LegalityTestClosure *cl = (LegalityTestClosure *) closure;
1585 if(board[rt][ft] != EmptySquare || kind==WhiteCapturesEnPassant || kind==BlackCapturesEnPassant)
1586 cl->captures++; // [HGM] losers: count legal captures
1587 if (rf == cl->rf && ff == cl->ff && rt == cl->rt && ft == cl->ft)
1592 LegalityTest (Board board, int flags, int rf, int ff, int rt, int ft, int promoChar)
1594 LegalityTestClosure cl; ChessSquare piece, filterPiece;
1596 if(quickFlag) flags = flags & ~1 | quickFlag & 1; // [HGM] speed: in quick mode quickFlag specifies side-to-move.
1597 if(rf == DROP_RANK) return LegalDrop(board, flags, ff, rt, ft);
1598 piece = filterPiece = board[rf][ff];
1599 if(PieceToChar(piece) == '~') filterPiece = DEMOTED piece;
1601 /* [HGM] Cobra and Falcon are wildcard pieces; consider all their moves legal */
1602 /* (perhaps we should disallow moves that obviously leave us in check?) */
1603 if((piece == WhiteFalcon || piece == BlackFalcon ||
1604 piece == WhiteCobra || piece == BlackCobra) && gameInfo.variant != VariantChu)
1605 return CheckTest(board, flags, rf, ff, rt, ft, FALSE) ? IllegalMove : NormalMove;
1609 cl.rt = rFilter = rt; // [HGM] speed: filter on to-square
1610 cl.ft = fFilter = ft;
1611 cl.kind = IllegalMove;
1612 cl.captures = 0; // [HGM] losers: prepare to count legal captures.
1613 if(flags & F_MANDATORY_CAPTURE) filterPiece = EmptySquare; // [HGM] speed: do not filter in suicide, to find all captures
1614 GenLegal(board, flags, LegalityTestCallback, (VOIDSTAR) &cl, filterPiece);
1615 if((flags & F_MANDATORY_CAPTURE) && cl.captures && board[rt][ft] == EmptySquare
1616 && cl.kind != WhiteCapturesEnPassant && cl.kind != BlackCapturesEnPassant)
1617 return(IllegalMove); // [HGM] losers: if there are legal captures, non-capts are illegal
1619 if(promoChar == 'x') promoChar = NULLCHAR; // [HGM] is this ever the case?
1620 if(gameInfo.variant == VariantSChess && promoChar && promoChar != '=' && board[rf][ff] != WhitePawn && board[rf][ff] != BlackPawn) {
1621 if(board[rf][ff] < BlackPawn) { // white
1622 if(rf != 0) return IllegalMove; // must be on back rank
1623 if(!(board[VIRGIN][ff] & VIRGIN_W)) return IllegalMove; // non-virgin
1624 if(board[PieceToNumber(CharToPiece(ToUpper(promoChar)))][BOARD_WIDTH-2] == 0) return ImpossibleMove;// must be in stock
1625 if(cl.kind == WhiteHSideCastleFR && (ff == BOARD_RGHT-2 || ff == BOARD_RGHT-3)) return ImpossibleMove;
1626 if(cl.kind == WhiteASideCastleFR && (ff == BOARD_LEFT+2 || ff == BOARD_LEFT+3)) return ImpossibleMove;
1628 if(rf != BOARD_HEIGHT-1) return IllegalMove;
1629 if(!(board[VIRGIN][ff] & VIRGIN_B)) return IllegalMove; // non-virgin
1630 if(board[BOARD_HEIGHT-1-PieceToNumber(CharToPiece(ToLower(promoChar)))][1] == 0) return ImpossibleMove;
1631 if(cl.kind == BlackHSideCastleFR && (ff == BOARD_RGHT-2 || ff == BOARD_RGHT-3)) return ImpossibleMove;
1632 if(cl.kind == BlackASideCastleFR && (ff == BOARD_LEFT+2 || ff == BOARD_LEFT+3)) return ImpossibleMove;
1635 if(gameInfo.variant == VariantChu) {
1636 if(cl.kind != NormalMove || promoChar == NULLCHAR || promoChar == '=') return cl.kind;
1637 if(promoChar != '+')
1638 return CharToPiece(promoChar) == EmptySquare ? ImpossibleMove : IllegalMove;
1639 if(PieceToChar(CHUPROMOTED board[rf][ff]) != '+') return ImpossibleMove;
1640 return flags & F_WHITE_ON_MOVE ? WhitePromotion : BlackPromotion;
1642 if(gameInfo.variant == VariantShogi) {
1643 /* [HGM] Shogi promotions. '=' means defer */
1644 if(rf != DROP_RANK && cl.kind == NormalMove) {
1645 ChessSquare piece = board[rf][ff];
1647 if(promoChar == PieceToChar(BlackQueen)) promoChar = NULLCHAR; /* [HGM] Kludge */
1648 if(promoChar == 'd' && (piece == WhiteRook || piece == BlackRook) ||
1649 promoChar == 'h' && (piece == WhiteBishop || piece == BlackBishop) ||
1650 promoChar == 'g' && (piece <= WhiteFerz || piece <= BlackFerz && piece >= BlackPawn) )
1651 promoChar = '+'; // allowed ICS notations
1652 if(appData.debugMode)fprintf(debugFP,"SHOGI promoChar = %c\n", promoChar ? promoChar : '-');
1653 if(promoChar != NULLCHAR && promoChar != '+' && promoChar != '=')
1654 return CharToPiece(promoChar) == EmptySquare ? ImpossibleMove : IllegalMove;
1655 else if(flags & F_WHITE_ON_MOVE) {
1656 if( (int) piece < (int) WhiteWazir &&
1657 (rf >= BOARD_HEIGHT - BOARD_HEIGHT/3 || rt >= BOARD_HEIGHT - BOARD_HEIGHT/3) ) {
1658 if( (piece == WhitePawn || piece == WhiteQueen) && rt > BOARD_HEIGHT-2 ||
1659 piece == WhiteKnight && rt > BOARD_HEIGHT-3) /* promotion mandatory */
1660 cl.kind = promoChar == '=' ? IllegalMove : WhitePromotion;
1661 else /* promotion optional, default is defer */
1662 cl.kind = promoChar == '+' ? WhitePromotion : WhiteNonPromotion;
1663 } else cl.kind = promoChar == '+' ? IllegalMove : NormalMove;
1665 if( (int) piece < (int) BlackWazir && (rf < BOARD_HEIGHT/3 || rt < BOARD_HEIGHT/3) ) {
1666 if( (piece == BlackPawn || piece == BlackQueen) && rt < 1 ||
1667 piece == BlackKnight && rt < 2 ) /* promotion obligatory */
1668 cl.kind = promoChar == '=' ? IllegalMove : BlackPromotion;
1669 else /* promotion optional, default is defer */
1670 cl.kind = promoChar == '+' ? BlackPromotion : BlackNonPromotion;
1671 } else cl.kind = promoChar == '+' ? IllegalMove : NormalMove;
1675 if (promoChar != NULLCHAR) {
1676 if(cl.kind == NormalMove && promoChar == '+') { // allow shogi-style promotion is pieceToChar specifies them
1677 ChessSquare piece = board[rf][ff];
1678 if(piece < BlackPawn ? piece > WhiteMan : piece > BlackMan) return ImpossibleMove; // already promoted
1679 // should test if in zone, really
1680 if(gameInfo.variant == VariantChuChess && (piece == WhiteKnight || piece == BlackKnight) && HasLion(board, flags))
1682 if(PieceToChar(PROMOTED piece) == '+') return flags & F_WHITE_ON_MOVE ? WhitePromotion : BlackPromotion;
1684 if(promoChar == '=') cl.kind = IllegalMove; else // [HGM] shogi: no deferred promotion outside Shogi
1685 if (cl.kind == WhitePromotion || cl.kind == BlackPromotion) {
1686 ChessSquare piece = CharToPiece(flags & F_WHITE_ON_MOVE ? ToUpper(promoChar) : ToLower(promoChar));
1687 if(piece == EmptySquare)
1688 cl.kind = ImpossibleMove; // non-existing piece
1689 if(gameInfo.variant == VariantChuChess && promoChar == 'l' && HasLion(board, flags)) {
1690 cl.kind = IllegalMove; // no two Lions
1691 } else if(gameInfo.variant == VariantSpartan && cl.kind == BlackPromotion ) {
1692 if(promoChar != PieceToChar(BlackKing)) {
1693 if(CheckTest(board, flags, rf, ff, rt, ft, FALSE)) cl.kind = IllegalMove; // [HGM] spartan: only promotion to King was possible
1694 if(piece == BlackLance) cl.kind = ImpossibleMove;
1695 } else { // promotion to King allowed only if we do not have two yet
1696 int r, f, kings = 0;
1697 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++) kings += (board[r][f] == BlackKing);
1698 if(kings == 2) cl.kind = IllegalMove;
1700 } else if(piece == WhitePawn && rt == BOARD_HEIGHT-1 ||
1701 piece == BlackPawn && rt == 0) cl.kind = IllegalMove; // cannot stay Pawn on last rank in any variant
1702 else if((piece == WhiteUnicorn || piece == BlackUnicorn) && gameInfo.variant == VariantKnightmate)
1703 cl.kind = IllegalMove; // promotion to Royal Knight not allowed
1704 else if((piece == WhiteKing || piece == BlackKing) && gameInfo.variant != VariantSuicide && gameInfo.variant != VariantGiveaway)
1705 cl.kind = IllegalMove; // promotion to King usually not allowed
1707 cl.kind = IllegalMove;
1717 extern void MateTestCallback P((Board board, int flags, ChessMove kind,
1718 int rf, int ff, int rt, int ft,
1722 MateTestCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1724 register MateTestClosure *cl = (MateTestClosure *) closure;
1729 /* Return MT_NONE, MT_CHECK, MT_CHECKMATE, or MT_STALEMATE */
1731 MateTest (Board board, int flags)
1734 int inCheck, r, f, myPieces=0, hisPieces=0, nrKing=0;
1735 ChessSquare king = flags & F_WHITE_ON_MOVE ? WhiteKing : BlackKing;
1737 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++) {
1738 // [HGM] losers: Count pieces and kings, to detect other unorthodox winning conditions
1739 nrKing += (board[r][f] == king); // stm has king
1740 if( board[r][f] != EmptySquare ) {
1741 if((int)board[r][f] <= (int)king && (int)board[r][f] >= (int)king - (int)WhiteKing + (int)WhitePawn)
1746 switch(gameInfo.variant) { // [HGM] losers: extinction wins
1747 case VariantShatranj:
1748 if(hisPieces == 1) return myPieces > 1 ? MT_BARE : MT_DRAW;
1752 if(nrKing == 0) return MT_NOKING;
1755 if(myPieces == 1) return MT_BARE;
1758 inCheck = GenLegal(board, flags, MateTestCallback, (VOIDSTAR) &cl, EmptySquare);
1759 // [HGM] 3check: yet to do!
1761 return inCheck ? MT_CHECK : MT_NONE;
1763 if(gameInfo.holdingsWidth && gameInfo.variant != VariantSuper && gameInfo.variant != VariantGreat
1764 && gameInfo.variant != VariantSChess && gameInfo.variant != VariantGrand) { // drop game
1765 int r, f, n, holdings = flags & F_WHITE_ON_MOVE ? BOARD_WIDTH-1 : 0;
1766 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++) if(board[r][f] == EmptySquare) // all empty squares
1767 for(n=0; n<BOARD_HEIGHT; n++) // all pieces in hand
1768 if(board[n][holdings] != EmptySquare) {
1769 int moveType = LegalDrop(board, flags, board[n][holdings], r, f);
1770 if(moveType == WhiteDrop || moveType == BlackDrop) return (inCheck ? MT_CHECK : MT_NONE); // we have legal drop
1773 if(gameInfo.variant == VariantSuicide) // [HGM] losers: always stalemate, since no check, but result varies
1774 return myPieces == hisPieces ? MT_STALEMATE :
1775 myPieces > hisPieces ? MT_STAINMATE : MT_STEALMATE;
1776 else if(gameInfo.variant == VariantLosers) return inCheck ? MT_TRICKMATE : MT_STEALMATE;
1777 else if(gameInfo.variant == VariantGiveaway) return MT_STEALMATE; // no check exists, stalemated = win
1779 return inCheck ? MT_CHECKMATE
1780 : (gameInfo.variant == VariantXiangqi || gameInfo.variant == VariantShatranj || IS_SHOGI(gameInfo.variant)) ?
1781 MT_STAINMATE : MT_STALEMATE;
1786 extern void DisambiguateCallback P((Board board, int flags, ChessMove kind,
1787 int rf, int ff, int rt, int ft,
1791 DisambiguateCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1793 register DisambiguateClosure *cl = (DisambiguateClosure *) closure;
1794 int wildCard = FALSE; ChessSquare piece = board[rf][ff];
1796 // [HGM] wild: for wild-card pieces rt and rf are dummies
1797 if(piece == WhiteFalcon || piece == BlackFalcon ||
1798 piece == WhiteCobra || piece == BlackCobra)
1801 if ((cl->pieceIn == EmptySquare || cl->pieceIn == board[rf][ff]
1802 || PieceToChar(board[rf][ff]) == '~'
1803 && cl->pieceIn == (ChessSquare)(DEMOTED board[rf][ff])
1805 (cl->rfIn == -1 || cl->rfIn == rf) &&
1806 (cl->ffIn == -1 || cl->ffIn == ff) &&
1807 (cl->rtIn == -1 || cl->rtIn == rt || wildCard) &&
1808 (cl->ftIn == -1 || cl->ftIn == ft || wildCard)) {
1811 if(cl->count == 1 || board[rt][ft] != EmptySquare) {
1812 // [HGM] oneclick: if multiple moves, be sure we remember capture
1813 cl->piece = board[rf][ff];
1816 cl->rt = wildCard ? cl->rtIn : rt;
1817 cl->ft = wildCard ? cl->ftIn : ft;
1820 cl->captures += (board[rt][ft] != EmptySquare); // [HGM] oneclick: count captures
1825 Disambiguate (Board board, int flags, DisambiguateClosure *closure)
1827 int illegal = 0; char c = closure->promoCharIn;
1829 if(quickFlag) flags = flags & ~1 | quickFlag & 1; // [HGM] speed: in quick mode quickFlag specifies side-to-move.
1830 closure->count = closure->captures = 0;
1831 closure->rf = closure->ff = closure->rt = closure->ft = 0;
1832 closure->kind = ImpossibleMove;
1833 rFilter = closure->rtIn; // [HGM] speed: only consider moves to given to-square
1834 fFilter = closure->ftIn;
1835 if(quickFlag) { // [HGM] speed: try without check test first, because if that is not ambiguous, we are happy
1836 GenLegal(board, flags|F_IGNORE_CHECK, DisambiguateCallback, (VOIDSTAR) closure, closure->pieceIn);
1837 if(closure->count > 1) { // gamble did not pay off. retry with check test to resolve ambiguity
1838 closure->count = closure->captures = 0;
1839 closure->rf = closure->ff = closure->rt = closure->ft = 0;
1840 closure->kind = ImpossibleMove;
1841 GenLegal(board, flags, DisambiguateCallback, (VOIDSTAR) closure, closure->pieceIn); // [HGM] speed: only pieces of requested type
1844 GenLegal(board, flags, DisambiguateCallback, (VOIDSTAR) closure, closure->pieceIn); // [HGM] speed: only pieces of requested type
1845 if (closure->count == 0) {
1846 /* See if it's an illegal move due to check */
1848 GenLegal(board, flags|F_IGNORE_CHECK, DisambiguateCallback, (VOIDSTAR) closure, closure->pieceIn);
1849 if (closure->count == 0) {
1850 /* No, it's not even that */
1851 if(!appData.testLegality && closure->pieceIn != EmptySquare) {
1852 int f, r; // if there is only a single piece of the requested type on the board, use that
1853 closure->rt = closure->rtIn, closure->ft = closure->ftIn;
1854 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++)
1855 if(board[r][f] == closure->pieceIn) closure->count++, closure->rf = r, closure->ff = f;
1856 if(closure->count > 1) illegal = 0; // ambiguous
1858 if(closure->count == 0) {
1859 if (appData.debugMode) { int i, j;
1860 for(i=BOARD_HEIGHT-1; i>=0; i--) {
1861 for(j=0; j<BOARD_WIDTH; j++)
1862 fprintf(debugFP, "%3d", (int) board[i][j]);
1863 fprintf(debugFP, "\n");
1871 if (c == 'x') c = NULLCHAR; // get rid of any 'x' (which should never happen?)
1872 if(gameInfo.variant == VariantSChess && c && c != '=' && closure->piece != WhitePawn && closure->piece != BlackPawn) {
1873 if(closure->piece < BlackPawn) { // white
1874 if(closure->rf != 0) closure->kind = IllegalMove; // must be on back rank
1875 if(!(board[VIRGIN][closure->ff] & VIRGIN_W)) closure->kind = IllegalMove; // non-virgin
1876 if(board[PieceToNumber(CharToPiece(ToUpper(c)))][BOARD_WIDTH-2] == 0) closure->kind = ImpossibleMove;// must be in stock
1877 if(closure->kind == WhiteHSideCastleFR && (closure->ff == BOARD_RGHT-2 || closure->ff == BOARD_RGHT-3)) closure->kind = ImpossibleMove;
1878 if(closure->kind == WhiteASideCastleFR && (closure->ff == BOARD_LEFT+2 || closure->ff == BOARD_LEFT+3)) closure->kind = ImpossibleMove;
1880 if(closure->rf != BOARD_HEIGHT-1) closure->kind = IllegalMove;
1881 if(!(board[VIRGIN][closure->ff] & VIRGIN_B)) closure->kind = IllegalMove; // non-virgin
1882 if(board[BOARD_HEIGHT-1-PieceToNumber(CharToPiece(ToLower(c)))][1] == 0) closure->kind = ImpossibleMove;
1883 if(closure->kind == BlackHSideCastleFR && (closure->ff == BOARD_RGHT-2 || closure->ff == BOARD_RGHT-3)) closure->kind = ImpossibleMove;
1884 if(closure->kind == BlackASideCastleFR && (closure->ff == BOARD_LEFT+2 || closure->ff == BOARD_LEFT+3)) closure->kind = ImpossibleMove;
1887 if(gameInfo.variant == VariantChu) {
1888 if(c == '+') closure->kind = (flags & F_WHITE_ON_MOVE ? WhitePromotion : BlackPromotion); // for now, accept any
1890 if(gameInfo.variant == VariantShogi) {
1891 /* [HGM] Shogi promotions. On input, '=' means defer, '+' promote. Afterwards, c is set to '+' for promotions, NULL other */
1892 if(closure->rfIn != DROP_RANK && closure->kind == NormalMove) {
1893 ChessSquare piece = closure->piece;
1894 if (c == 'd' && (piece == WhiteRook || piece == BlackRook) ||
1895 c == 'h' && (piece == WhiteBishop || piece == BlackBishop) ||
1896 c == 'g' && (piece <= WhiteFerz || piece <= BlackFerz && piece >= BlackPawn) )
1897 c = '+'; // allowed ICS notations
1898 if(c != NULLCHAR && c != '+' && c != '=') closure->kind = IllegalMove; // otherwise specifying a piece is illegal
1899 else if(flags & F_WHITE_ON_MOVE) {
1900 if( (int) piece < (int) WhiteWazir &&
1901 (closure->rf >= BOARD_HEIGHT-(BOARD_HEIGHT/3) || closure->rt >= BOARD_HEIGHT-(BOARD_HEIGHT/3)) ) {
1902 if( (piece == WhitePawn || piece == WhiteQueen) && closure->rt > BOARD_HEIGHT-2 ||
1903 piece == WhiteKnight && closure->rt > BOARD_HEIGHT-3) /* promotion mandatory */
1904 closure->kind = c == '=' ? IllegalMove : WhitePromotion;
1905 else /* promotion optional, default is defer */
1906 closure->kind = c == '+' ? WhitePromotion : WhiteNonPromotion;
1907 } else closure->kind = c == '+' ? IllegalMove : NormalMove;
1909 if( (int) piece < (int) BlackWazir && (closure->rf < BOARD_HEIGHT/3 || closure->rt < BOARD_HEIGHT/3) ) {
1910 if( (piece == BlackPawn || piece == BlackQueen) && closure->rt < 1 ||
1911 piece == BlackKnight && closure->rt < 2 ) /* promotion obligatory */
1912 closure->kind = c == '=' ? IllegalMove : BlackPromotion;
1913 else /* promotion optional, default is defer */
1914 closure->kind = c == '+' ? BlackPromotion : BlackNonPromotion;
1915 } else closure->kind = c == '+' ? IllegalMove : NormalMove;
1918 if(closure->kind == WhitePromotion || closure->kind == BlackPromotion) c = '+'; else
1919 if(closure->kind == WhiteNonPromotion || closure->kind == BlackNonPromotion) c = '=';
1921 if (closure->kind == WhitePromotion || closure->kind == BlackPromotion) {
1922 if(c == NULLCHAR) { // missing promoChar on mandatory promotion; use default for variant
1923 if(gameInfo.variant == VariantShatranj || gameInfo.variant == VariantCourier ||
1924 gameInfo.variant == VariantMakruk || gameInfo.variant == VariantASEAN)
1925 c = PieceToChar(BlackFerz);
1926 else if(gameInfo.variant == VariantGreat)
1927 c = PieceToChar(BlackMan);
1928 else if(gameInfo.variant == VariantGrand)
1929 closure->kind = closure->rt != 0 && closure->rt != BOARD_HEIGHT-1 ? NormalMove : AmbiguousMove; // no default in Grand Chess
1931 c = PieceToChar(BlackQueen);
1932 } else if(c == '=') closure->kind = IllegalMove; // no deferral outside Shogi
1933 else if(c == 'l' && gameInfo.variant == VariantChuChess && HasLion(board, flags)) closure->kind = IllegalMove;
1934 } else if (c == '+') { // '+' outside shogi, check if pieceToCharTable enabled it
1935 ChessSquare p = closure->piece;
1936 if(p > WhiteMan && p < BlackPawn || p > BlackMan || PieceToChar(PROMOTED p) != '+')
1937 closure->kind = ImpossibleMove; // used on non-promotable piece
1938 else if(gameInfo.variant == VariantChuChess && HasLion(board, flags)) closure->kind = IllegalMove;
1939 } else if (c != NULLCHAR) closure->kind = IllegalMove;
1941 closure->promoChar = ToLower(c); // this can be NULLCHAR! Note we keep original promoChar even if illegal.
1942 if(c != '+' && c != '=' && c != NULLCHAR && CharToPiece(flags & F_WHITE_ON_MOVE ? ToUpper(c) : ToLower(c)) == EmptySquare)
1943 closure->kind = ImpossibleMove; // but we cannot handle non-existing piece types!
1944 if (closure->count > 1) {
1945 closure->kind = AmbiguousMove;
1948 /* Note: If more than one illegal move matches, but no legal
1949 moves, we return IllegalMove, not AmbiguousMove. Caller
1950 can look at closure->count to detect this.
1952 closure->kind = IllegalMove;
1966 } CoordsToAlgebraicClosure;
1968 extern void CoordsToAlgebraicCallback P((Board board, int flags,
1969 ChessMove kind, int rf, int ff,
1970 int rt, int ft, VOIDSTAR closure));
1973 CoordsToAlgebraicCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1975 register CoordsToAlgebraicClosure *cl =
1976 (CoordsToAlgebraicClosure *) closure;
1978 if ((rt == cl->rt && ft == cl->ft || rt == rf && ft == ff) && // [HGM] null move matches any toSquare
1979 (board[rf][ff] == cl->piece
1980 || PieceToChar(board[rf][ff]) == '~' &&
1981 (ChessSquare) (DEMOTED board[rf][ff]) == cl->piece)
1985 cl->kind = kind; /* this is the move we want */
1987 cl->file++; /* need file to rule out this move */
1991 cl->rank++; /* need rank to rule out this move */
1993 cl->either++; /* rank or file will rule out this move */
1999 /* Convert coordinates to normal algebraic notation.
2000 promoChar must be NULLCHAR or 'x' if not a promotion.
2003 CoordsToAlgebraic (Board board, int flags, int rf, int ff, int rt, int ft, int promoChar, char out[MOVE_LEN])
2007 char *outp = out, c, capture;
2008 CoordsToAlgebraicClosure cl;
2010 if (rf == DROP_RANK) {
2011 if(ff == EmptySquare) { strncpy(outp, "--",3); return NormalMove; } // [HGM] pass
2012 /* Bughouse piece drop */
2013 *outp++ = ToUpper(PieceToChar((ChessSquare) ff));
2018 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2020 return (flags & F_WHITE_ON_MOVE) ? WhiteDrop : BlackDrop;
2023 if (promoChar == 'x') promoChar = NULLCHAR;
2024 piece = board[rf][ff];
2025 if(PieceToChar(piece)=='~') piece = (ChessSquare)(DEMOTED piece);
2030 kind = LegalityTest(board, flags, rf, ff, rt, ft, promoChar);
2031 if (kind == IllegalMove && !(flags&F_IGNORE_CHECK)) {
2032 /* Keep short notation if move is illegal only because it
2033 leaves the player in check, but still return IllegalMove */
2034 kind = LegalityTest(board, flags|F_IGNORE_CHECK, rf, ff, rt, ft, promoChar);
2035 if (kind == IllegalMove) break;
2040 capture = board[rt][ft] != EmptySquare || kind == WhiteCapturesEnPassant || kind == BlackCapturesEnPassant;
2041 if (ff == ft && !capture) { /* [HGM] Xiangqi has straight noncapts! */
2042 /* Non-capture; use style "e5" */
2045 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2047 /* Capture; use style "exd5" */
2049 *outp++ = 'x'; /* [HGM] Xiangqi has sideway noncaptures across river! */
2053 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2055 /* Use promotion suffix style "=Q" */
2057 if (promoChar != NULLCHAR) {
2058 if(IS_SHOGI(gameInfo.variant)) {
2059 /* [HGM] ... but not in Shogi! */
2060 *outp++ = promoChar == '=' ? '=' : '+';
2063 *outp++ = ToUpper(promoChar);
2072 /* Fabien moved code: FRC castling first (if KxR), wild castling second */
2073 /* Code added by Tord: FRC castling. */
2074 if((piece == WhiteKing && board[rt][ft] == WhiteRook) ||
2075 (piece == BlackKing && board[rt][ft] == BlackRook)) {
2077 safeStrCpy(out, "O-O", MOVE_LEN);
2079 safeStrCpy(out, "O-O-O", MOVE_LEN);
2080 return LegalityTest(board, flags, rf, ff, rt, ft, promoChar);
2082 /* End of code added by Tord */
2083 /* Test for castling or ICS wild castling */
2084 /* Use style "O-O" (oh-oh) for PGN compatibility */
2085 else if (rf == rt &&
2086 rf == ((piece == WhiteKing) ? 0 : BOARD_HEIGHT-1) &&
2087 (ft - ff > 1 || ff - ft > 1) && // No castling if legal King move (on narrow boards!)
2088 ((ff == BOARD_WIDTH>>1 && (ft == BOARD_LEFT+2 || ft == BOARD_RGHT-2)) ||
2089 (ff == (BOARD_WIDTH-1)>>1 && (ft == BOARD_LEFT+1 || ft == BOARD_RGHT-3)))) {
2090 if(ft==BOARD_LEFT+1 || ft==BOARD_RGHT-2)
2091 snprintf(out, MOVE_LEN, "O-O%c%c", promoChar ? '/' : 0, ToUpper(promoChar));
2093 snprintf(out, MOVE_LEN, "O-O-O%c%c", promoChar ? '/' : 0, ToUpper(promoChar));
2095 /* This notation is always unambiguous, unless there are
2096 kings on both the d and e files, with "wild castling"
2097 possible for the king on the d file and normal castling
2098 possible for the other. ICS rules for wild 9
2099 effectively make castling illegal for either king in
2100 this situation. So I am not going to worry about it;
2101 I'll just generate an ambiguous O-O in this case.
2103 return LegalityTest(board, flags, rf, ff, rt, ft, promoChar);
2106 /* else fall through */
2111 cl.rt = rFilter = rt; // [HGM] speed: filter on to-square
2112 cl.ft = fFilter = ft;
2114 cl.kind = IllegalMove;
2115 cl.rank = cl.file = cl.either = 0;
2116 c = PieceToChar(piece) ;
2117 GenLegal(board, flags, CoordsToAlgebraicCallback, (VOIDSTAR) &cl, c!='~' ? piece : (DEMOTED piece)); // [HGM] speed
2119 if (cl.kind == IllegalMove && !(flags&F_IGNORE_CHECK)) {
2120 /* Generate pretty moves for moving into check, but
2121 still return IllegalMove.
2123 GenLegal(board, flags|F_IGNORE_CHECK, CoordsToAlgebraicCallback, (VOIDSTAR) &cl, c!='~' ? piece : (DEMOTED piece));
2124 if (cl.kind == IllegalMove) break;
2125 cl.kind = IllegalMove;
2128 /* Style is "Nf3" or "Nxf7" if this is unambiguous,
2129 else "Ngf3" or "Ngxf7",
2130 else "N1f3" or "N5xf7",
2131 else "Ng1f3" or "Ng5xf7".
2133 if( c == '~' || c == '+') {
2134 /* [HGM] print nonexistent piece as its demoted version */
2135 piece = (ChessSquare) (DEMOTED piece - 11*(gameInfo.variant == VariantChu));
2137 if(c=='+') *outp++ = c;
2138 *outp++ = ToUpper(PieceToChar(piece));
2140 if (cl.file || (cl.either && !cl.rank)) {
2146 else { *outp++ = (rf+ONE-'0')/10 + '0';*outp++ = (rf+ONE-'0')%10 + '0'; }
2149 if(board[rt][ft] != EmptySquare)
2155 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2156 if (IS_SHOGI(gameInfo.variant)) {
2157 /* [HGM] in Shogi non-pawns can promote */
2158 *outp++ = promoChar; // Don't bother to correct move type, return value is never used!
2160 else if (gameInfo.variant == VariantChuChess && promoChar ||
2161 gameInfo.variant != VariantSuper && promoChar &&
2162 (piece == WhiteLance || piece == BlackLance) ) { // Lance sometimes represents Pawn
2164 *outp++ = ToUpper(promoChar);
2166 else if (gameInfo.variant == VariantSChess && promoChar) { // and in S-Chess we have gating
2168 *outp++ = ToUpper(promoChar);
2174 /* Moving a nonexistent piece */
2178 /* Not a legal move, even ignoring check.
2179 If there was a piece on the from square,
2180 use style "Ng1g3" or "Ng1xe8";
2181 if there was a pawn or nothing (!),
2182 use style "g1g3" or "g1xe8". Use "x"
2183 if a piece was on the to square, even
2184 a piece of the same color.
2188 if (piece != EmptySquare && piece != WhitePawn && piece != BlackPawn) {
2190 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<=BOARD_RGHT; f++)
2191 c += (board[r][f] == piece); // count on-board pieces of given type
2192 *outp++ = ToUpper(PieceToChar(piece));
2194 if(c != 1) { // [HGM] but if there is only one piece of the mentioned type, no from-square, thank you!
2198 else { *outp++ = (rf+ONE-'0')/10 + '0';*outp++ = (rf+ONE-'0')%10 + '0'; }
2200 if (board[rt][ft] != EmptySquare) *outp++ = 'x';
2204 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2205 /* Use promotion suffix style "=Q" */
2206 if (promoChar != NULLCHAR && promoChar != 'x') {
2208 *outp++ = ToUpper(promoChar);
2215 // [HGM] XQ: the following code serves to detect perpetual chasing (Asian rules)
2224 // I guess the following variables logically belong in the closure too, but I was too lazy and used globals
2226 int preyStackPointer, chaseStackPointer;
2229 unsigned char rf, ff, rt, ft;
2233 unsigned char rank, file;
2239 // there are three new callbacks for use with GenLegal: for adding captures, deleting them, and finding a recapture
2241 extern void AtacksCallback P((Board board, int flags, ChessMove kind,
2242 int rf, int ff, int rt, int ft,
2246 AttacksCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
2247 { // For adding captures that can lead to chase indictment to the chaseStack
2248 if(board[rt][ft] == EmptySquare) return; // non-capture
2249 if(board[rt][ft] == WhitePawn && rt < BOARD_HEIGHT/2) return; // Pawn before river can be chased
2250 if(board[rt][ft] == BlackPawn && rt >= BOARD_HEIGHT/2) return; // Pawn before river can be chased
2251 if(board[rf][ff] == WhitePawn || board[rf][ff] == BlackPawn) return; // Pawns are allowed to chase
2252 if(board[rf][ff] == WhiteWazir || board[rf][ff] == BlackWazir) return; // King is allowed to chase
2253 // move cannot be excluded from being a chase trivially (based on attacker and victim); save it on chaseStack
2254 chaseStack[chaseStackPointer].rf = rf;
2255 chaseStack[chaseStackPointer].ff = ff;
2256 chaseStack[chaseStackPointer].rt = rt;
2257 chaseStack[chaseStackPointer].ft = ft;
2258 chaseStackPointer++;
2261 extern void ExistingAtacksCallback P((Board board, int flags, ChessMove kind,
2262 int rf, int ff, int rt, int ft,
2266 ExistingAttacksCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
2267 { // for removing pre-exsting captures from the chaseStack, to be left with newly created ones
2269 register ChaseClosure *cl = (ChaseClosure *) closure; //closure tells us the move played in the repeat loop
2271 if(board[rt][ft] == EmptySquare) return; // no capture
2272 if(rf == cl->rf && ff == cl->ff) { // attacks with same piece from new position are not considered new
2273 rf = cl->rt; ff = cl->ft; // doctor their fromSquare so they will be recognized in chaseStack
2275 // search move in chaseStack, and delete it if it occurred there (as we know now it is not a new capture)
2276 for(i=0; i<chaseStackPointer; i++) {
2277 if(chaseStack[i].rf == rf && chaseStack[i].ff == ff &&
2278 chaseStack[i].rt == rt && chaseStack[i].ft == ft ) {
2279 // move found on chaseStack, delete it by overwriting with move popped from top of chaseStack
2280 chaseStack[i] = chaseStack[--chaseStackPointer];
2286 extern void ProtectedCallback P((Board board, int flags, ChessMove kind,
2287 int rf, int ff, int rt, int ft,
2291 ProtectedCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
2292 { // for determining if a piece (given through the closure) is protected
2293 register ChaseClosure *cl = (ChaseClosure *) closure; // closure tells us where to recapture
2295 if(rt == cl->rt && ft == cl->ft) cl->recaptures++; // count legal recaptures to this square
2296 if(appData.debugMode && board[rt][ft] != EmptySquare)
2297 fprintf(debugFP, "try %c%c%c%c=%d\n", ff+AAA, rf+ONE,ft+AAA, rt+ONE, cl->recaptures);
2300 extern char moveList[MAX_MOVES][MOVE_LEN];
2303 PerpetualChase (int first, int last)
2304 { // this routine detects if the side to move in the 'first' position is perpetually chasing (when not checking)
2307 ChessSquare captured;
2309 preyStackPointer = 0; // clear stack of chased pieces
2310 for(i=first; i<last; i+=2) { // for all positions with same side to move
2311 if(appData.debugMode) fprintf(debugFP, "judge position %i\n", i);
2312 chaseStackPointer = 0; // clear stack that is going to hold possible chases
2313 // determine all captures possible after the move, and put them on chaseStack
2314 GenLegal(boards[i+1], PosFlags(i), AttacksCallback, &cl, EmptySquare);
2315 if(appData.debugMode) { int n;
2316 for(n=0; n<chaseStackPointer; n++)
2317 fprintf(debugFP, "%c%c%c%c ", chaseStack[n].ff+AAA, chaseStack[n].rf+ONE,
2318 chaseStack[n].ft+AAA, chaseStack[n].rt+ONE);
2319 fprintf(debugFP, ": all capts\n");
2321 // determine all captures possible before the move, and delete them from chaseStack
2322 cl.rf = moveList[i][1]-ONE; // prepare closure to pass move that led from i to i+1
2323 cl.ff = moveList[i][0]-AAA+BOARD_LEFT;
2324 cl.rt = moveList[i][3]-ONE;
2325 cl.ft = moveList[i][2]-AAA+BOARD_LEFT;
2326 CopyBoard(xqCheckers, nullBoard); xqCheckers[EP_STATUS] = 1; // giant kludge to make GenLegal ignore pre-existing checks
2327 GenLegal(boards[i], PosFlags(i), ExistingAttacksCallback, &cl, EmptySquare);
2328 xqCheckers[EP_STATUS] = 0; // disable the generation of quasi-legal moves again
2329 if(appData.debugMode) { int n;
2330 for(n=0; n<chaseStackPointer; n++)
2331 fprintf(debugFP, "%c%c%c%c ", chaseStack[n].ff+AAA, chaseStack[n].rf+ONE,
2332 chaseStack[n].ft+AAA, chaseStack[n].rt+ONE);
2333 fprintf(debugFP, ": new capts after %c%c%c%c\n", cl.ff+AAA, cl.rf+ONE, cl.ft+AAA, cl.rt+ONE);
2335 // chaseSack now contains all captures made possible by the move
2336 for(j=0; j<chaseStackPointer; j++) { // run through chaseStack to identify true chases
2337 int attacker = (int)boards[i+1][chaseStack[j].rf][chaseStack[j].ff];
2338 int victim = (int)boards[i+1][chaseStack[j].rt][chaseStack[j].ft];
2340 if(attacker >= (int) BlackPawn) attacker = BLACK_TO_WHITE attacker; // convert to white, as piecee type
2341 if(victim >= (int) BlackPawn) victim = BLACK_TO_WHITE victim;
2343 if((attacker == WhiteKnight || attacker == WhiteCannon) && victim == WhiteRook)
2344 continue; // C or H attack on R is always chase; leave on chaseStack
2346 if(attacker == victim) {
2347 if(LegalityTest(boards[i+1], PosFlags(i+1), chaseStack[j].rt,
2348 chaseStack[j].ft, chaseStack[j].rf, chaseStack[j].ff, NULLCHAR) == NormalMove) {
2349 // we can capture back with equal piece, so this is no chase but a sacrifice
2350 chaseStack[j] = chaseStack[--chaseStackPointer]; // delete the capture from the chaseStack
2351 j--; /* ! */ continue;
2356 // the attack is on a lower piece, or on a pinned or blocked equal one
2357 CopyBoard(xqCheckers, nullBoard); xqCheckers[EP_STATUS] = 1;
2358 CheckTest(boards[i+1], PosFlags(i+1), -1, -1, -1, -1, FALSE); // if we deliver check with our move, the checkers get marked
2359 // test if the victim is protected by a true protector. First make the capture.
2360 captured = boards[i+1][chaseStack[j].rt][chaseStack[j].ft];
2361 boards[i+1][chaseStack[j].rt][chaseStack[j].ft] = boards[i+1][chaseStack[j].rf][chaseStack[j].ff];
2362 boards[i+1][chaseStack[j].rf][chaseStack[j].ff] = EmptySquare;
2363 // Then test if the opponent can recapture
2364 cl.recaptures = 0; // prepare closure to pass recapture square and count moves to it
2365 cl.rt = chaseStack[j].rt;
2366 cl.ft = chaseStack[j].ft;
2367 if(appData.debugMode) {
2368 fprintf(debugFP, "test if we can recapture %c%c\n", cl.ft+AAA, cl.rt+ONE);
2370 xqCheckers[EP_STATUS] = 2; // causes GenLegal to ignore the checks we delivered with the move, in real life evaded before we captured
2371 GenLegal(boards[i+1], PosFlags(i+1), ProtectedCallback, &cl, EmptySquare); // try all moves
2372 xqCheckers[EP_STATUS] = 0; // disable quasi-legal moves again
2373 // unmake the capture
2374 boards[i+1][chaseStack[j].rf][chaseStack[j].ff] = boards[i+1][chaseStack[j].rt][chaseStack[j].ft];
2375 boards[i+1][chaseStack[j].rt][chaseStack[j].ft] = captured;
2376 // if a recapture was found, piece is protected, and we are not chasing it.
2377 if(cl.recaptures) { // attacked piece was defended by true protector, no chase
2378 chaseStack[j] = chaseStack[--chaseStackPointer]; // so delete from chaseStack
2382 // chaseStack now contains all moves that chased
2383 if(appData.debugMode) { int n;
2384 for(n=0; n<chaseStackPointer; n++)
2385 fprintf(debugFP, "%c%c%c%c ", chaseStack[n].ff+AAA, chaseStack[n].rf+ONE,
2386 chaseStack[n].ft+AAA, chaseStack[n].rt+ONE);
2387 fprintf(debugFP, ": chases\n");
2389 if(i == first) { // copy all people chased by first move of repeat cycle to preyStack
2390 for(j=0; j<chaseStackPointer; j++) {
2391 preyStack[j].rank = chaseStack[j].rt;
2392 preyStack[j].file = chaseStack[j].ft;
2394 preyStackPointer = chaseStackPointer;
2397 for(j=0; j<chaseStackPointer; j++) {
2398 for(k=0; k<preyStackPointer; k++) {
2399 // search the victim of each chase move on the preyStack (first occurrence)
2400 if(chaseStack[j].ft == preyStack[k].file && chaseStack[j].rt == preyStack[k].rank ) {
2401 if(k < tail) break; // piece was already identified as still being chased
2402 preyStack[preyStackPointer] = preyStack[tail]; // move chased piece to bottom part of preyStack
2403 preyStack[tail] = preyStack[k]; // by swapping
2404 preyStack[k] = preyStack[preyStackPointer];
2410 preyStackPointer = tail; // keep bottom part of preyStack, popping pieces unchased on move i.
2411 if(appData.debugMode) { int n;
2412 for(n=0; n<preyStackPointer; n++)
2413 fprintf(debugFP, "%c%c ", preyStack[n].file+AAA, preyStack[n].rank+ONE);
2414 fprintf(debugFP, "always chased upto ply %d\n", i);
2416 // now adjust the location of the chased pieces according to opponent move
2417 for(j=0; j<preyStackPointer; j++) {
2418 if(preyStack[j].rank == moveList[i+1][1]-ONE &&
2419 preyStack[j].file == moveList[i+1][0]-AAA+BOARD_LEFT) {
2420 preyStack[j].rank = moveList[i+1][3]-ONE;
2421 preyStack[j].file = moveList[i+1][2]-AAA+BOARD_LEFT;
2426 return preyStackPointer ? 256*(preyStack[preyStackPointer].file - BOARD_LEFT + AAA) + (preyStack[preyStackPointer].rank + ONE)
2427 : 0; // if any piece was left on preyStack, it has been perpetually chased,and we return the