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]) continue;
261 if(expo > 1 && dx == 0 && dy == 0) { // castling indicated by O + number
265 for(dir=0, bit=1; dir<8; dir++, bit += bit) { // loop over directions
266 int i = expo, hop = mode, vx, vy;
267 if(!(bit & dirSet)) continue; // does not move in this direction
268 vx = dx*rot[dir][0] + dy*rot[dir][1]; // rotate step vector
269 vy = dx*rot[dir][2] + dy*rot[dir][3];
270 x = f; y = r; // start square
272 x += vx; y += vy; // step to next square
273 if(y < 0 || y >= BOARD_HEIGHT || x < BOARD_LEFT || x >= BOARD_RGHT) break;
274 if(!jump && board[y - vy + vy/2][x - vx + vx/2] != EmptySquare) break; // blocked
275 if(jump > 1 && board[y - vy + vy/2][x - vx + vx/2] == EmptySquare) break; // no hop
276 if(board[y][x] < BlackPawn) occup = 1; else
277 if(board[y][x] < EmptySquare) occup = 2; else
279 if(hop & 32+64) { if(occup != 4) { if(hop & 64 && i != 1) i = 2; hop &= 31; } continue; } // hopper
280 if(mode & 8 && y == board[EP_RANK] && occup == 4 && board[EP_FILE] == x) { // to e.p. square
281 cb(board, flags, mine == 1 ? WhiteCapturesEnPassant : BlackCapturesEnPassant, r, f, y, x, cl);
283 if(mode & 16) { // castling
284 i = 2; // kludge to elongate move indefinitely
285 if(occup == 4) continue; // skip empty squares
286 if(x == BOARD_LEFT && board[y][x] == initialPosition[y][x]) // reached initial corner piece
287 cb(board, flags, mine == 1 ? WhiteQueenSideCastle : BlackQueenSideCastle, r, f, y, f - expo, cl);
288 if(x == BOARD_RGHT-1 && board[y][x] == initialPosition[y][x])
289 cb(board, flags, mine == 1 ? WhiteKingSideCastle : BlackKingSideCastle, r, f, y, f + expo, cl);
292 if(occup & mode) cb(board, flags, NormalMove, r, f, y, x, cl); // allowed, generate
293 if(occup != 4) break; // not valid transit square
296 dx = dy = 1; dirSet = 0x99; // prepare for diagonal moves of K,Q
297 } while(retry--); // and start doing them
301 // [HGM] move generation now based on hierarchy of subroutines for rays and combinations of rays
304 SlideForward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
309 if (rt >= BOARD_HEIGHT) break;
310 if (SameColor(board[rf][ff], board[rt][ft])) break;
311 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
312 if (board[rt][ft] != EmptySquare) break;
317 SlideBackward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
323 if (SameColor(board[rf][ff], board[rt][ft])) break;
324 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
325 if (board[rt][ft] != EmptySquare) break;
330 SlideVertical (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
332 SlideForward(board, flags, rf, ff, callback, closure);
333 SlideBackward(board, flags, rf, ff, callback, closure);
337 SlideSideways (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
339 int i, s, rt = rf, ft;
340 for(s = -1; s <= 1; s+= 2) {
343 if (ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
344 if (SameColor(board[rf][ff], board[rt][ft])) break;
345 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
346 if (board[rt][ft] != EmptySquare) break;
352 SlideDiagForward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
355 for(s = -1; s <= 1; s+= 2) {
359 if (rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
360 if (SameColor(board[rf][ff], board[rt][ft])) break;
361 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
362 if (board[rt][ft] != EmptySquare) break;
368 SlideDiagBackward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
371 for(s = -1; s <= 1; s+= 2) {
375 if (rt < 0 || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
376 if (SameColor(board[rf][ff], board[rt][ft])) break;
377 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
378 if (board[rt][ft] != EmptySquare) break;
384 Rook (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
386 SlideVertical(board, flags, rf, ff, callback, closure);
387 SlideSideways(board, flags, rf, ff, callback, closure);
391 Bishop (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
393 SlideDiagForward(board, flags, rf, ff, callback, closure);
394 SlideDiagBackward(board, flags, rf, ff, callback, closure);
398 Sting (Board board, int flags, int rf, int ff, int dy, int dx, MoveCallback callback, VOIDSTAR closure)
399 { // Lion-like move of Horned Falcon and Souring Eagle
400 int ft = ff + dx, rt = rf + dy;
401 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) return;
402 if (!SameColor(board[rf][ff], board[rt][ft]))
403 callback(board, flags, board[rt][ft] != EmptySquare ? FirstLeg : NormalMove, rf, ff, rt, ft, closure);
405 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) return;
406 if (!SameColor(board[rf][ff], board[rt][ft]))
407 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
411 StepForward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
413 int ft = ff, rt = rf + 1;
414 if (rt >= BOARD_HEIGHT) return;
415 if (SameColor(board[rf][ff], board[rt][ft])) return;
416 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
420 StepBackward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
422 int ft = ff, rt = rf - 1;
424 if (SameColor(board[rf][ff], board[rt][ft])) return;
425 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
429 StepSideways (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
433 if (!(rt >= BOARD_HEIGHT || ft >= BOARD_RGHT) && !SameColor(board[rf][ff], board[rt][ft]))
434 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
436 if (!(rt >= BOARD_HEIGHT || ft < BOARD_LEFT) && !SameColor(board[rf][ff], board[rt][ft]))
437 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
441 StepDiagForward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
444 if (rt >= BOARD_HEIGHT) return;
446 if (!(rt >= BOARD_HEIGHT || ft >= BOARD_RGHT) && !SameColor(board[rf][ff], board[rt][ft]))
447 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
449 if (!(rt >= BOARD_HEIGHT || ft < BOARD_LEFT) && !SameColor(board[rf][ff], board[rt][ft]))
450 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
454 StepDiagBackward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
459 if (!(rt < 0 || ft >= BOARD_RGHT) && !SameColor(board[rf][ff], board[rt][ft]))
460 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
462 if (!(rt < 0 || ft < BOARD_LEFT) && !SameColor(board[rf][ff], board[rt][ft]))
463 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
467 StepVertical (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
469 StepForward(board, flags, rf, ff, callback, closure);
470 StepBackward(board, flags, rf, ff, callback, closure);
474 Ferz (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
476 StepDiagForward(board, flags, rf, ff, callback, closure);
477 StepDiagBackward(board, flags, rf, ff, callback, closure);
481 Wazir (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
483 StepVertical(board, flags, rf, ff, callback, closure);
484 StepSideways(board, flags, rf, ff, callback, closure);
488 Knight (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
491 for (i = -1; i <= 1; i += 2)
492 for (j = -1; j <= 1; j += 2)
493 for (s = 1; s <= 2; s++) {
496 if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
497 && ( gameInfo.variant != VariantXiangqi || board[rf+i*(s-1)][ff+j*(2-s)] == EmptySquare)
498 && !SameColor(board[rf][ff], board[rt][ft]))
499 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
503 /* Call callback once for each pseudo-legal move in the given
504 position, except castling moves. A move is pseudo-legal if it is
505 legal, or if it would be legal except that it leaves the king in
506 check. In the arguments, epfile is EP_NONE if the previous move
507 was not a double pawn push, or the file 0..7 if it was, or
508 EP_UNKNOWN if we don't know and want to allow all e.p. captures.
509 Promotion moves generated are to Queen only.
512 GenPseudoLegal (Board board, int flags, MoveCallback callback, VOIDSTAR closure, ChessSquare filter)
513 // speed: only do moves with this piece type
516 int i, j, d, s, fs, rs, rt, ft, m;
517 int epfile = (signed char)board[EP_STATUS]; // [HGM] gamestate: extract ep status from board
518 int promoRank = gameInfo.variant == VariantMakruk || gameInfo.variant == VariantGrand || gameInfo.variant == VariantChuChess ? 3 : 1;
520 for (rf = 0; rf < BOARD_HEIGHT; rf++)
521 for (ff = BOARD_LEFT; ff < BOARD_RGHT; ff++) {
524 if(board[rf][ff] == EmptySquare) continue;
525 if ((flags & F_WHITE_ON_MOVE) != (board[rf][ff] < BlackPawn)) continue; // [HGM] speed: wrong color
526 m = 0; piece = board[rf][ff];
527 if(PieceToChar(piece) == '~')
528 piece = (ChessSquare) ( DEMOTED piece );
529 if(filter != EmptySquare && piece != filter) continue;
530 if(pieceDesc[piece]) { MovesFromString(board, flags, ff, rf, pieceDesc[piece], callback, closure); continue; } // [HGM] gen
531 if(IS_SHOGI(gameInfo.variant))
532 piece = (ChessSquare) ( SHOGI piece );
534 switch ((int)piece) {
535 /* case EmptySquare: [HGM] this is nonsense, and conflicts with Shogi cases */
537 /* can't happen ([HGM] except for faries...) */
541 if(gameInfo.variant == VariantXiangqi) {
542 /* [HGM] capture and move straight ahead in Xiangqi */
543 if (rf < BOARD_HEIGHT-1 &&
544 !SameColor(board[rf][ff], board[rf + 1][ff]) ) {
545 callback(board, flags, NormalMove,
546 rf, ff, rf + 1, ff, closure);
548 /* and move sideways when across the river */
549 for (s = -1; s <= 1; s += 2) {
550 if (rf >= BOARD_HEIGHT>>1 &&
551 ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
552 !WhitePiece(board[rf][ff+s]) ) {
553 callback(board, flags, NormalMove,
554 rf, ff, rf, ff+s, closure);
559 if (rf < BOARD_HEIGHT-1 && board[rf + 1][ff] == EmptySquare) {
560 callback(board, flags,
561 rf >= BOARD_HEIGHT-1-promoRank ? WhitePromotion : NormalMove,
562 rf, ff, rf + 1, ff, closure);
564 if (rf <= (BOARD_HEIGHT>>1)-3 && board[rf+1][ff] == EmptySquare && // [HGM] grand: also on 3rd rank on 10-board
565 gameInfo.variant != VariantShatranj && /* [HGM] */
566 gameInfo.variant != VariantCourier && /* [HGM] */
567 board[rf+2][ff] == EmptySquare ) {
568 callback(board, flags, NormalMove,
569 rf, ff, rf+2, ff, closure);
571 for (s = -1; s <= 1; s += 2) {
572 if (rf < BOARD_HEIGHT-1 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
573 ((flags & F_KRIEGSPIEL_CAPTURE) ||
574 BlackPiece(board[rf + 1][ff + s]))) {
575 callback(board, flags,
576 rf >= BOARD_HEIGHT-1-promoRank ? WhitePromotion : NormalMove,
577 rf, ff, rf + 1, ff + s, closure);
579 if (rf >= BOARD_HEIGHT+1>>1) {// [HGM] grand: 4th & 5th rank on 10-board
580 if (ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
581 (epfile == ff + s || epfile == EP_UNKNOWN) && rf < BOARD_HEIGHT-3 &&
582 board[rf][ff + s] == BlackPawn &&
583 board[rf+1][ff + s] == EmptySquare) {
584 callback(board, flags, WhiteCapturesEnPassant,
585 rf, ff, rf+1, ff + s, closure);
592 if(gameInfo.variant == VariantXiangqi) {
593 /* [HGM] capture straight ahead in Xiangqi */
594 if (rf > 0 && !SameColor(board[rf][ff], board[rf - 1][ff]) ) {
595 callback(board, flags, NormalMove,
596 rf, ff, rf - 1, ff, closure);
598 /* and move sideways when across the river */
599 for (s = -1; s <= 1; s += 2) {
600 if (rf < BOARD_HEIGHT>>1 &&
601 ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
602 !BlackPiece(board[rf][ff+s]) ) {
603 callback(board, flags, NormalMove,
604 rf, ff, rf, ff+s, closure);
609 if (rf > 0 && board[rf - 1][ff] == EmptySquare) {
610 callback(board, flags,
611 rf <= promoRank ? BlackPromotion : NormalMove,
612 rf, ff, rf - 1, ff, closure);
614 if (rf >= (BOARD_HEIGHT+1>>1)+2 && board[rf-1][ff] == EmptySquare && // [HGM] grand
615 gameInfo.variant != VariantShatranj && /* [HGM] */
616 gameInfo.variant != VariantCourier && /* [HGM] */
617 board[rf-2][ff] == EmptySquare) {
618 callback(board, flags, NormalMove,
619 rf, ff, rf-2, ff, closure);
621 for (s = -1; s <= 1; s += 2) {
622 if (rf > 0 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
623 ((flags & F_KRIEGSPIEL_CAPTURE) ||
624 WhitePiece(board[rf - 1][ff + s]))) {
625 callback(board, flags,
626 rf <= promoRank ? BlackPromotion : NormalMove,
627 rf, ff, rf - 1, ff + s, closure);
629 if (rf < BOARD_HEIGHT>>1) {
630 if (ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
631 (epfile == ff + s || epfile == EP_UNKNOWN) && rf > 2 &&
632 board[rf][ff + s] == WhitePawn &&
633 board[rf-1][ff + s] == EmptySquare) {
634 callback(board, flags, BlackCapturesEnPassant,
635 rf, ff, rf-1, ff + s, closure);
645 for (i = -1; i <= 1; i += 2)
646 for (j = -1; j <= 1; j += 2)
647 for (s = 1; s <= 2; s++) {
650 if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
651 && ( gameInfo.variant != VariantXiangqi || board[rf+i*(s-1)][ff+j*(2-s)] == EmptySquare)
652 && !SameColor(board[rf][ff], board[rt][ft]))
653 callback(board, flags, NormalMove,
654 rf, ff, rt, ft, closure);
658 case SHOGI WhiteKnight:
659 for (s = -1; s <= 1; s += 2) {
660 if (rf < BOARD_HEIGHT-2 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
661 !SameColor(board[rf][ff], board[rf + 2][ff + s])) {
662 callback(board, flags, NormalMove,
663 rf, ff, rf + 2, ff + s, closure);
668 case SHOGI BlackKnight:
669 for (s = -1; s <= 1; s += 2) {
670 if (rf > 1 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
671 !SameColor(board[rf][ff], board[rf - 2][ff + s])) {
672 callback(board, flags, NormalMove,
673 rf, ff, rf - 2, ff + s, closure);
680 for (d = 0; d <= 1; d++)
681 for (s = -1; s <= 1; s += 2) {
684 rt = rf + (i * s) * d;
685 ft = ff + (i * s) * (1 - d);
686 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
687 if (m == 0 && board[rt][ft] == EmptySquare)
688 callback(board, flags, NormalMove,
689 rf, ff, rt, ft, closure);
690 if (m == 1 && board[rt][ft] != EmptySquare &&
691 !SameColor(board[rf][ff], board[rt][ft]) )
692 callback(board, flags, NormalMove,
693 rf, ff, rt, ft, closure);
694 if (board[rt][ft] != EmptySquare && m++) break;
699 /* Gold General (and all its promoted versions) . First do the */
700 /* diagonal forward steps, then proceed as normal Wazir */
701 case SHOGI (PROMOTED WhitePawn):
702 if(gameInfo.variant == VariantShogi) goto WhiteGold;
703 case SHOGI (PROMOTED BlackPawn):
704 if(gameInfo.variant == VariantShogi) goto BlackGold;
705 SlideVertical(board, flags, rf, ff, callback, closure);
708 case SHOGI (PROMOTED WhiteKnight):
709 if(gameInfo.variant == VariantShogi) goto WhiteGold;
710 case SHOGI BlackDrunk:
711 case SHOGI BlackAlfil:
712 Ferz(board, flags, rf, ff, callback, closure);
713 StepSideways(board, flags, rf, ff, callback, closure);
714 StepBackward(board, flags, rf, ff, callback, closure);
717 case SHOGI (PROMOTED BlackKnight):
718 if(gameInfo.variant == VariantShogi) goto BlackGold;
719 case SHOGI WhiteDrunk:
720 case SHOGI WhiteAlfil:
721 Ferz(board, flags, rf, ff, callback, closure);
722 StepSideways(board, flags, rf, ff, callback, closure);
723 StepForward(board, flags, rf, ff, callback, closure);
727 case SHOGI WhiteStag:
728 case SHOGI BlackStag:
729 if(gameInfo.variant == VariantShogi) goto BlackGold;
730 SlideVertical(board, flags, rf, ff, callback, closure);
731 Ferz(board, flags, rf, ff, callback, closure);
732 StepSideways(board, flags, rf, ff, callback, closure);
735 case SHOGI (PROMOTED WhiteQueen):
736 case SHOGI WhiteTokin:
737 case SHOGI WhiteWazir:
739 StepDiagForward(board, flags, rf, ff, callback, closure);
740 Wazir(board, flags, rf, ff, callback, closure);
743 case SHOGI (PROMOTED BlackQueen):
744 case SHOGI BlackTokin:
745 case SHOGI BlackWazir:
747 StepDiagBackward(board, flags, rf, ff, callback, closure);
748 Wazir(board, flags, rf, ff, callback, closure);
753 Wazir(board, flags, rf, ff, callback, closure);
756 case SHOGI WhiteMarshall:
757 case SHOGI BlackMarshall:
758 Ferz(board, flags, rf, ff, callback, closure);
759 for (d = 0; d <= 1; d++)
760 for (s = -2; s <= 2; s += 4) {
762 ft = ff + s * (1 - d);
763 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) continue;
764 if (!SameColor(board[rf][ff], board[rt][ft]) )
765 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
769 case SHOGI WhiteAngel:
770 case SHOGI BlackAngel:
771 Wazir(board, flags, rf, ff, callback, closure);
775 /* [HGM] support Shatranj pieces */
776 for (rs = -1; rs <= 1; rs += 2)
777 for (fs = -1; fs <= 1; fs += 2) {
780 if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
781 && ( gameInfo.variant != VariantXiangqi ||
782 board[rf+rs][ff+fs] == EmptySquare && (2*rf < BOARD_HEIGHT) == (2*rt < BOARD_HEIGHT) )
784 && !SameColor(board[rf][ff], board[rt][ft]))
785 callback(board, flags, NormalMove,
786 rf, ff, rt, ft, closure);
787 if(gameInfo.variant == VariantShatranj || gameInfo.variant == VariantCourier ||
788 gameInfo.variant == VariantChu || gameInfo.variant == VariantXiangqi) continue; // classical Alfil
789 rt = rf + rs; // in unknown variant we assume Modern Elephant, which can also do one step
791 if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
792 && !SameColor(board[rf][ff], board[rt][ft]))
793 callback(board, flags, NormalMove,
794 rf, ff, rt, ft, closure);
796 if(gameInfo.variant == VariantSpartan)
797 for(fs = -1; fs <= 1; fs += 2) {
799 if (!(ft < BOARD_LEFT || ft >= BOARD_RGHT) && board[rf][ft] == EmptySquare)
800 callback(board, flags, NormalMove, rf, ff, rf, ft, closure);
804 /* Make Dragon-Horse also do Dababba moves outside Shogi, for better disambiguation in variant Fairy */
807 if(gameInfo.variant == VariantChuChess) goto DragonHorse;
808 for (d = 0; d <= 1; d++) // Dababba moves that Rook cannot do
809 for (s = -2; s <= 2; s += 4) {
811 ft = ff + s * (1 - d);
812 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) continue;
813 if (SameColor(board[rf][ff], board[rt][ft])) continue;
814 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
817 /* Shogi Dragon Horse has to continue with Wazir after Bishop */
818 case SHOGI WhiteCardinal:
819 case SHOGI BlackCardinal:
820 case SHOGI WhitePCardinal:
821 case SHOGI BlackPCardinal:
823 Bishop(board, flags, rf, ff, callback, closure);
824 Wazir(board, flags, rf, ff, callback, closure);
827 /* Capablanca Archbishop continues as Knight */
830 Knight(board, flags, rf, ff, callback, closure);
832 /* Shogi Bishops are ordinary Bishops */
833 case SHOGI WhiteBishop:
834 case SHOGI BlackBishop:
835 case SHOGI WhitePBishop:
836 case SHOGI BlackPBishop:
839 Bishop(board, flags, rf, ff, callback, closure);
842 /* Shogi Lance is unlike anything, and asymmetric at that */
843 case SHOGI WhiteQueen:
844 if(gameInfo.variant == VariantChu) goto doQueen;
848 if (rt >= BOARD_HEIGHT) break;
849 if (SameColor(board[rf][ff], board[rt][ft])) break;
850 callback(board, flags, NormalMove,
851 rf, ff, rt, ft, closure);
852 if (board[rt][ft] != EmptySquare) break;
856 case SHOGI BlackQueen:
857 if(gameInfo.variant == VariantChu) goto doQueen;
862 if (SameColor(board[rf][ff], board[rt][ft])) break;
863 callback(board, flags, NormalMove,
864 rf, ff, rt, ft, closure);
865 if (board[rt][ft] != EmptySquare) break;
869 /* Make Dragon-King Dababba & Rook-like outside Shogi, for better disambiguation in variant Fairy */
872 if(gameInfo.variant == VariantChuChess) goto DragonKing;
873 for (d = 0; d <= 1; d++) // Dababba moves that Rook cannot do
874 for (s = -2; s <= 2; s += 4) {
876 ft = ff + s * (1 - d);
877 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) continue;
878 if (board[rf+rt>>1][ff+ft>>1] == EmptySquare && gameInfo.variant != VariantSpartan) continue;
879 if (SameColor(board[rf][ff], board[rt][ft])) continue;
880 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
882 if(gameInfo.variant == VariantSpartan) // in Spartan Chess restrict range to modern Dababba
883 Wazir(board, flags, rf, ff, callback, closure);
885 Rook(board, flags, rf, ff, callback, closure);
888 /* Shogi Dragon King has to continue as Ferz after Rook moves */
889 case SHOGI WhiteDragon:
890 case SHOGI BlackDragon:
891 case SHOGI WhitePDragon:
892 case SHOGI BlackPDragon:
894 Rook(board, flags, rf, ff, callback, closure);
895 Ferz(board, flags, rf, ff, callback, closure);
899 /* Capablanca Chancellor sets flag to continue as Knight */
902 Rook(board, flags, rf, ff, callback, closure);
903 if(gameInfo.variant == VariantSpartan) // in Spartan Chess Chancellor is used for Dragon King.
904 Ferz(board, flags, rf, ff, callback, closure);
906 Knight(board, flags, rf, ff, callback, closure);
909 /* Shogi Rooks are ordinary Rooks */
910 case SHOGI WhiteRook:
911 case SHOGI BlackRook:
912 case SHOGI WhitePRook:
913 case SHOGI BlackPRook:
916 Rook(board, flags, rf, ff, callback, closure);
921 case SHOGI WhiteMother:
922 case SHOGI BlackMother:
924 Rook(board, flags, rf, ff, callback, closure);
925 Bishop(board, flags, rf, ff, callback, closure);
928 case SHOGI WhitePawn:
929 StepForward(board, flags, rf, ff, callback, closure);
932 case SHOGI BlackPawn:
933 StepBackward(board, flags, rf, ff, callback, closure);
937 if(gameInfo.variant != VariantMakruk && gameInfo.variant != VariantASEAN) goto commoner;
938 case SHOGI WhiteFerz:
939 Ferz(board, flags, rf, ff, callback, closure);
940 StepForward(board, flags, rf, ff, callback, closure);
944 if(gameInfo.variant != VariantMakruk && gameInfo.variant != VariantASEAN) goto commoner;
945 case SHOGI BlackFerz:
946 StepBackward(board, flags, rf, ff, callback, closure);
950 /* [HGM] support Shatranj pieces */
951 Ferz(board, flags, rf, ff, callback, closure);
956 Knight(board, flags, rf, ff, callback, closure); // [HGM] superchess: use for Centaur
959 case SHOGI WhiteMonarch:
960 case SHOGI BlackMonarch:
961 case SHOGI WhiteKing:
962 case SHOGI BlackKing:
965 Ferz(board, flags, rf, ff, callback, closure);
966 Wazir(board, flags, rf, ff, callback, closure);
969 case WhiteNightrider:
970 case BlackNightrider:
971 for (i = -1; i <= 1; i += 2)
972 for (j = -1; j <= 1; j += 2)
973 for (s = 1; s <= 2; s++) { int k;
977 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
978 if (SameColor(board[rf][ff], board[rt][ft])) break;
979 callback(board, flags, NormalMove,
980 rf, ff, rt, ft, closure);
981 if (board[rt][ft] != EmptySquare) break;
987 Bishop(board, flags, rf, ff, callback, closure);
988 Rook(board, flags, rf, ff, callback, closure);
989 Knight(board, flags, rf, ff, callback, closure);
992 // Use Lance as Berolina / Spartan Pawn.
994 if(gameInfo.variant == VariantSuper) goto Amazon;
995 if (rf < BOARD_HEIGHT-1 && BlackPiece(board[rf + 1][ff]))
996 callback(board, flags,
997 rf >= BOARD_HEIGHT-1-promoRank ? WhitePromotion : NormalMove,
998 rf, ff, rf + 1, ff, closure);
999 for (s = -1; s <= 1; s += 2) {
1000 if (rf < BOARD_HEIGHT-1 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT && board[rf + 1][ff + s] == EmptySquare)
1001 callback(board, flags,
1002 rf >= BOARD_HEIGHT-1-promoRank ? WhitePromotion : NormalMove,
1003 rf, ff, rf + 1, ff + s, closure);
1004 if (rf == 1 && ff + 2*s >= BOARD_LEFT && ff + 2*s < BOARD_RGHT && board[3][ff + 2*s] == EmptySquare )
1005 callback(board, flags, NormalMove, rf, ff, 3, ff + 2*s, closure);
1010 if(gameInfo.variant == VariantSuper) goto Amazon;
1011 if (rf > 0 && WhitePiece(board[rf - 1][ff]))
1012 callback(board, flags,
1013 rf <= promoRank ? BlackPromotion : NormalMove,
1014 rf, ff, rf - 1, ff, closure);
1015 for (s = -1; s <= 1; s += 2) {
1016 if (rf > 0 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT && board[rf - 1][ff + s] == EmptySquare)
1017 callback(board, flags,
1018 rf <= promoRank ? BlackPromotion : NormalMove,
1019 rf, ff, rf - 1, ff + s, closure);
1020 if (rf == BOARD_HEIGHT-2 && ff + 2*s >= BOARD_LEFT && ff + 2*s < BOARD_RGHT && board[rf-2][ff + 2*s] == EmptySquare )
1021 callback(board, flags, NormalMove, rf, ff, rf-2, ff + 2*s, closure);
1025 case SHOGI WhiteNothing:
1026 case SHOGI BlackNothing:
1027 case SHOGI WhiteLion:
1028 case SHOGI BlackLion:
1031 for(rt = rf - 2; rt <= rf + 2; rt++) for(ft = ff - 2; ft <= ff + 2; ft++) {
1032 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) continue;
1033 if (!(ff == ft && rf == rt) && SameColor(board[rf][ff], board[rt][ft])) continue;
1034 callback(board, flags, (rt-rf)*(rt-rf) + (ff-ft)*(ff-ft) < 3 && board[rt][ft] != EmptySquare ? FirstLeg : NormalMove,
1035 rf, ff, rt, ft, closure);
1039 case SHOGI WhiteFalcon:
1040 case SHOGI BlackFalcon:
1041 case SHOGI WhitePDagger:
1042 case SHOGI BlackPDagger:
1043 SlideSideways(board, flags, rf, ff, callback, closure);
1044 StepVertical(board, flags, rf, ff, callback, closure);
1047 case SHOGI WhiteCobra:
1048 case SHOGI BlackCobra:
1049 StepVertical(board, flags, rf, ff, callback, closure);
1052 case SHOGI (PROMOTED WhiteFerz):
1053 if(gameInfo.variant == VariantShogi) goto WhiteGold;
1054 case SHOGI (PROMOTED BlackFerz):
1055 if(gameInfo.variant == VariantShogi) goto BlackGold;
1056 case SHOGI WhitePSword:
1057 case SHOGI BlackPSword:
1058 SlideVertical(board, flags, rf, ff, callback, closure);
1059 StepSideways(board, flags, rf, ff, callback, closure);
1062 case SHOGI WhiteUnicorn:
1063 case SHOGI BlackUnicorn:
1064 Ferz(board, flags, rf, ff, callback, closure);
1065 StepVertical(board, flags, rf, ff, callback, closure);
1068 case SHOGI WhiteMan:
1069 StepDiagForward(board, flags, rf, ff, callback, closure);
1070 StepVertical(board, flags, rf, ff, callback, closure);
1073 case SHOGI BlackMan:
1074 StepDiagBackward(board, flags, rf, ff, callback, closure);
1075 StepVertical(board, flags, rf, ff, callback, closure);
1078 case SHOGI WhiteHCrown:
1079 case SHOGI BlackHCrown:
1080 Bishop(board, flags, rf, ff, callback, closure);
1081 SlideSideways(board, flags, rf, ff, callback, closure);
1084 case SHOGI WhiteCrown:
1085 case SHOGI BlackCrown:
1086 Bishop(board, flags, rf, ff, callback, closure);
1087 SlideVertical(board, flags, rf, ff, callback, closure);
1090 case SHOGI WhiteHorned:
1091 Sting(board, flags, rf, ff, 1, 0, callback, closure);
1092 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1093 if(killX >= 0) break;
1094 Bishop(board, flags, rf, ff, callback, closure);
1095 SlideSideways(board, flags, rf, ff, callback, closure);
1096 SlideBackward(board, flags, rf, ff, callback, closure);
1099 case SHOGI BlackHorned:
1100 Sting(board, flags, rf, ff, -1, 0, callback, closure);
1101 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1102 if(killX >= 0) break;
1103 Bishop(board, flags, rf, ff, callback, closure);
1104 SlideSideways(board, flags, rf, ff, callback, closure);
1105 SlideForward(board, flags, rf, ff, callback, closure);
1108 case SHOGI WhiteEagle:
1109 Sting(board, flags, rf, ff, 1, 1, callback, closure);
1110 Sting(board, flags, rf, ff, 1, -1, callback, closure);
1111 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1112 if(killX >= 0) break;
1113 Rook(board, flags, rf, ff, callback, closure);
1114 SlideDiagBackward(board, flags, rf, ff, callback, closure);
1117 case SHOGI BlackEagle:
1118 Sting(board, flags, rf, ff, -1, 1, callback, closure);
1119 Sting(board, flags, rf, ff, -1, -1, callback, closure);
1120 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1121 if(killX >= 0) break;
1122 Rook(board, flags, rf, ff, callback, closure);
1123 SlideDiagForward(board, flags, rf, ff, callback, closure);
1126 case SHOGI WhiteDolphin:
1127 case SHOGI BlackHorse:
1128 SlideDiagBackward(board, flags, rf, ff, callback, closure);
1129 SlideVertical(board, flags, rf, ff, callback, closure);
1132 case SHOGI BlackDolphin:
1133 case SHOGI WhiteHorse:
1134 SlideDiagForward(board, flags, rf, ff, callback, closure);
1135 SlideVertical(board, flags, rf, ff, callback, closure);
1138 case SHOGI WhiteLance:
1139 SlideForward(board, flags, rf, ff, callback, closure);
1142 case SHOGI BlackLance:
1143 SlideBackward(board, flags, rf, ff, callback, closure);
1146 case WhiteFalcon: // [HGM] wild: for wildcards, self-capture symbolizes move to anywhere
1150 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1163 int rFilter, fFilter; // [HGM] speed: sorry, but I get a bit tired of this closure madness
1164 Board xqCheckers, nullBoard;
1166 extern void GenLegalCallback P((Board board, int flags, ChessMove kind,
1167 int rf, int ff, int rt, int ft,
1171 GenLegalCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1173 register GenLegalClosure *cl = (GenLegalClosure *) closure;
1175 if(rFilter >= 0 && rFilter != rt || fFilter >= 0 && fFilter != ft) return; // [HGM] speed: ignore moves with wrong to-square
1177 if (board[EP_STATUS] == EP_IRON_LION && (board[rt][ft] == WhiteLion || board[rt][ft] == BlackLion)) return; //[HGM] lion
1179 if (!(flags & F_IGNORE_CHECK) ) {
1180 int check, promo = (gameInfo.variant == VariantSpartan && kind == BlackPromotion);
1183 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++)
1184 kings += (board[r][f] == BlackKing);
1188 board[rf][ff] = BlackKing; // [HGM] spartan: promote to King before check-test
1190 check = CheckTest(board, flags, rf, ff, rt, ft,
1191 kind == WhiteCapturesEnPassant ||
1192 kind == BlackCapturesEnPassant);
1193 if(promo) board[rf][ff] = BlackLance;
1196 if (flags & F_ATOMIC_CAPTURE) {
1197 if (board[rt][ft] != EmptySquare ||
1198 kind == WhiteCapturesEnPassant || kind == BlackCapturesEnPassant) {
1200 ChessSquare king = (flags & F_WHITE_ON_MOVE) ? WhiteKing : BlackKing;
1201 if (board[rf][ff] == king) return;
1202 for (r = rt-1; r <= rt+1; r++) {
1203 for (f = ft-1; f <= ft+1; f++) {
1204 if (r >= 0 && r < BOARD_HEIGHT && f >= BOARD_LEFT && f < BOARD_RGHT &&
1205 board[r][f] == king) return;
1210 cl->cb(board, flags, kind, rf, ff, rt, ft, cl->cl);
1217 int captures; // [HGM] losers
1218 } LegalityTestClosure;
1221 /* Like GenPseudoLegal, but (1) include castling moves, (2) unless
1222 F_IGNORE_CHECK is set in the flags, omit moves that would leave the
1223 king in check, and (3) if F_ATOMIC_CAPTURE is set in the flags, omit
1224 moves that would destroy your own king. The CASTLE_OK flags are
1225 true if castling is not yet ruled out by a move of the king or
1226 rook. Return TRUE if the player on move is currently in check and
1227 F_IGNORE_CHECK is not set. [HGM] add castlingRights parameter */
1229 GenLegal (Board board, int flags, MoveCallback callback, VOIDSTAR closure, ChessSquare filter)
1232 int ff, ft, k, left, right, swap;
1233 int ignoreCheck = (flags & F_IGNORE_CHECK) != 0;
1234 ChessSquare wKing = WhiteKing, bKing = BlackKing, *castlingRights = board[CASTLING];
1235 int inCheck = !ignoreCheck && CheckTest(board, flags, -1, -1, -1, -1, FALSE); // kludge alert: this would mark pre-existing checkers if status==1
1240 xqCheckers[EP_STATUS] *= 2; // quasi: if previous CheckTest has been marking, we now set flag for suspending same checkers
1241 if(filter == EmptySquare) rFilter = fFilter = -1; // [HGM] speed: do not filter on square if we do not filter on piece
1242 GenPseudoLegal(board, flags, GenLegalCallback, (VOIDSTAR) &cl, filter);
1244 if (inCheck) return TRUE;
1246 /* Generate castling moves */
1247 if(gameInfo.variant == VariantKnightmate) { /* [HGM] Knightmate */
1248 wKing = WhiteUnicorn; bKing = BlackUnicorn;
1251 p = (flags & F_WHITE_ON_MOVE ? pieceDesc[wKing] : pieceDesc[bKing]);
1252 if(p && strchr(p, 'O')) return FALSE; // [HGM] gen: castlings were already generated from string
1254 for (ff = BOARD_WIDTH>>1; ff >= (BOARD_WIDTH-1)>>1; ff-- /*ics wild 1*/) {
1255 if ((flags & F_WHITE_ON_MOVE) &&
1256 (flags & F_WHITE_KCASTLE_OK) &&
1257 board[0][ff] == wKing &&
1258 board[0][ff + 1] == EmptySquare &&
1259 board[0][ff + 2] == EmptySquare &&
1260 board[0][BOARD_RGHT-3] == EmptySquare &&
1261 board[0][BOARD_RGHT-2] == EmptySquare &&
1262 board[0][BOARD_RGHT-1] == WhiteRook &&
1263 castlingRights[0] != NoRights && /* [HGM] check rights */
1264 ( castlingRights[2] == ff || castlingRights[6] == ff ) &&
1266 (!CheckTest(board, flags, 0, ff, 0, ff + 1, FALSE) &&
1267 !CheckTest(board, flags, 0, ff, 0, BOARD_RGHT-3, FALSE) &&
1268 (gameInfo.variant != VariantJanus || !CheckTest(board, flags, 0, ff, 0, BOARD_RGHT-2, FALSE)) &&
1269 !CheckTest(board, flags, 0, ff, 0, ff + 2, FALSE)))) {
1271 callback(board, flags,
1272 ff==BOARD_WIDTH>>1 ? WhiteKingSideCastle : WhiteKingSideCastleWild,
1273 0, ff, 0, ff + ((gameInfo.boardWidth+2)>>2) + (gameInfo.variant == VariantJanus), closure);
1275 if ((flags & F_WHITE_ON_MOVE) &&
1276 (flags & F_WHITE_QCASTLE_OK) &&
1277 board[0][ff] == wKing &&
1278 board[0][ff - 1] == EmptySquare &&
1279 board[0][ff - 2] == EmptySquare &&
1280 board[0][BOARD_LEFT+2] == EmptySquare &&
1281 board[0][BOARD_LEFT+1] == EmptySquare &&
1282 board[0][BOARD_LEFT+0] == WhiteRook &&
1283 castlingRights[1] != NoRights && /* [HGM] check rights */
1284 ( castlingRights[2] == ff || castlingRights[6] == ff ) &&
1286 (!CheckTest(board, flags, 0, ff, 0, ff - 1, FALSE) &&
1287 !CheckTest(board, flags, 0, ff, 0, BOARD_LEFT+3, FALSE) &&
1288 !CheckTest(board, flags, 0, ff, 0, ff - 2, FALSE)))) {
1290 callback(board, flags,
1291 ff==BOARD_WIDTH>>1 ? WhiteQueenSideCastle : WhiteQueenSideCastleWild,
1292 0, ff, 0, ff - ((gameInfo.boardWidth+2)>>2), closure);
1294 if (!(flags & F_WHITE_ON_MOVE) &&
1295 (flags & F_BLACK_KCASTLE_OK) &&
1296 board[BOARD_HEIGHT-1][ff] == bKing &&
1297 board[BOARD_HEIGHT-1][ff + 1] == EmptySquare &&
1298 board[BOARD_HEIGHT-1][ff + 2] == EmptySquare &&
1299 board[BOARD_HEIGHT-1][BOARD_RGHT-3] == EmptySquare &&
1300 board[BOARD_HEIGHT-1][BOARD_RGHT-2] == EmptySquare &&
1301 board[BOARD_HEIGHT-1][BOARD_RGHT-1] == BlackRook &&
1302 castlingRights[3] != NoRights && /* [HGM] check rights */
1303 ( castlingRights[5] == ff || castlingRights[7] == ff ) &&
1305 (!CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff + 1, FALSE) &&
1306 !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, BOARD_RGHT-3, FALSE) &&
1307 (gameInfo.variant != VariantJanus || !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, BOARD_RGHT-2, FALSE)) &&
1308 !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff + 2, FALSE)))) {
1310 callback(board, flags,
1311 ff==BOARD_WIDTH>>1 ? BlackKingSideCastle : BlackKingSideCastleWild,
1312 BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff + ((gameInfo.boardWidth+2)>>2) + (gameInfo.variant == VariantJanus), closure);
1314 if (!(flags & F_WHITE_ON_MOVE) &&
1315 (flags & F_BLACK_QCASTLE_OK) &&
1316 board[BOARD_HEIGHT-1][ff] == bKing &&
1317 board[BOARD_HEIGHT-1][ff - 1] == EmptySquare &&
1318 board[BOARD_HEIGHT-1][ff - 2] == EmptySquare &&
1319 board[BOARD_HEIGHT-1][BOARD_LEFT+2] == EmptySquare &&
1320 board[BOARD_HEIGHT-1][BOARD_LEFT+1] == EmptySquare &&
1321 board[BOARD_HEIGHT-1][BOARD_LEFT+0] == BlackRook &&
1322 castlingRights[4] != NoRights && /* [HGM] check rights */
1323 ( castlingRights[5] == ff || castlingRights[7] == ff ) &&
1325 (!CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff - 1, FALSE) &&
1326 !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, BOARD_LEFT+3, FALSE) &&
1327 !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff - 2, FALSE)))) {
1329 callback(board, flags,
1330 ff==BOARD_WIDTH>>1 ? BlackQueenSideCastle : BlackQueenSideCastleWild,
1331 BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff - ((gameInfo.boardWidth+2)>>2), closure);
1335 if((swap = gameInfo.variant == VariantSChess) || flags & F_FRC_TYPE_CASTLING) {
1337 /* generate all potential FRC castling moves (KxR), ignoring flags */
1338 /* [HGM] test if the Rooks we find have castling rights */
1339 /* In S-Chess we generate RxK for allowed castlings, for gating at Rook square */
1342 if ((flags & F_WHITE_ON_MOVE) != 0) {
1343 ff = castlingRights[2]; /* King file if we have any rights */
1344 if(ff != NoRights && board[0][ff] == WhiteKing) {
1345 if (appData.debugMode) {
1346 fprintf(debugFP, "FRC castling, %d %d %d %d %d %d\n",
1347 castlingRights[0],castlingRights[1],ff,castlingRights[3],castlingRights[4],castlingRights[5]);
1349 ft = castlingRights[0]; /* Rook file if we have H-side rights */
1351 right = BOARD_RGHT-2;
1352 if(ff == BOARD_RGHT-2) left = right = ff-1; /* special case */
1353 for(k=left; k<=right && ft != NoRights; k++) /* first test if blocked */
1354 if(k != ft && board[0][k] != EmptySquare) ft = NoRights;
1355 for(k=left; k<right && ft != NoRights; k++) /* then if not checked */
1356 if(!ignoreCheck && CheckTest(board, flags, 0, ff, 0, k, FALSE)) ft = NoRights;
1357 if(ft != NoRights && board[0][ft] == WhiteRook) {
1358 if(flags & F_FRC_TYPE_CASTLING) callback(board, flags, WhiteHSideCastleFR, 0, ff, 0, ft, closure);
1359 if(swap) callback(board, flags, WhiteHSideCastleFR, 0, ft, 0, ff, closure);
1362 ft = castlingRights[1]; /* Rook file if we have A-side rights */
1363 left = BOARD_LEFT+2;
1365 if(ff <= BOARD_LEFT+2) { left = ff+1; right = BOARD_LEFT+3; }
1366 for(k=left; k<=right && ft != NoRights; k++) /* first test if blocked */
1367 if(k != ft && board[0][k] != EmptySquare) ft = NoRights;
1368 if(ft == 0 && ff != 1 && board[0][1] != EmptySquare) ft = NoRights; /* Rook can be blocked on b1 */
1369 if(ff > BOARD_LEFT+2)
1370 for(k=left+1; k<=right && ft != NoRights; k++) /* then if not checked */
1371 if(!ignoreCheck && CheckTest(board, flags, 0, ff, 0, k, FALSE)) ft = NoRights;
1372 if(ft != NoRights && board[0][ft] == WhiteRook) {
1373 if(flags & F_FRC_TYPE_CASTLING) callback(board, flags, WhiteASideCastleFR, 0, ff, 0, ft, closure);
1374 if(swap) callback(board, flags, WhiteASideCastleFR, 0, ft, 0, ff, closure);
1378 ff = castlingRights[5]; /* King file if we have any rights */
1379 if(ff != NoRights && board[BOARD_HEIGHT-1][ff] == BlackKing) {
1380 ft = castlingRights[3]; /* Rook file if we have H-side rights */
1382 right = BOARD_RGHT-2;
1383 if(ff == BOARD_RGHT-2) left = right = ff-1; /* special case */
1384 for(k=left; k<=right && ft != NoRights; k++) /* first test if blocked */
1385 if(k != ft && board[BOARD_HEIGHT-1][k] != EmptySquare) ft = NoRights;
1386 for(k=left; k<right && ft != NoRights; k++) /* then if not checked */
1387 if(!ignoreCheck && CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, k, FALSE)) ft = NoRights;
1388 if(ft != NoRights && board[BOARD_HEIGHT-1][ft] == BlackRook) {
1389 if(flags & F_FRC_TYPE_CASTLING) callback(board, flags, BlackHSideCastleFR, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ft, closure);
1390 if(swap) callback(board, flags, BlackHSideCastleFR, BOARD_HEIGHT-1, ft, BOARD_HEIGHT-1, ff, closure);
1393 ft = castlingRights[4]; /* Rook file if we have A-side rights */
1394 left = BOARD_LEFT+2;
1396 if(ff <= BOARD_LEFT+2) { left = ff+1; right = BOARD_LEFT+3; }
1397 for(k=left; k<=right && ft != NoRights; k++) /* first test if blocked */
1398 if(k != ft && board[BOARD_HEIGHT-1][k] != EmptySquare) ft = NoRights;
1399 if(ft == 0 && ff != 1 && board[BOARD_HEIGHT-1][1] != EmptySquare) ft = NoRights; /* Rook can be blocked on b8 */
1400 if(ff > BOARD_LEFT+2)
1401 for(k=left+1; k<=right && ft != NoRights; k++) /* then if not checked */
1402 if(!ignoreCheck && CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, k, FALSE)) ft = NoRights;
1403 if(ft != NoRights && board[BOARD_HEIGHT-1][ft] == BlackRook) {
1404 if(flags & F_FRC_TYPE_CASTLING) callback(board, flags, BlackASideCastleFR, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ft, closure);
1405 if(swap) callback(board, flags, BlackASideCastleFR, BOARD_HEIGHT-1, ft, BOARD_HEIGHT-1, ff, closure);
1422 extern void CheckTestCallback P((Board board, int flags, ChessMove kind,
1423 int rf, int ff, int rt, int ft,
1428 CheckTestCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1430 register CheckTestClosure *cl = (CheckTestClosure *) closure;
1432 if (rt == cl->rking && ft == cl->fking) {
1433 if(xqCheckers[EP_STATUS] >= 2 && xqCheckers[rf][ff]) return; // checker is piece with suspended checking power
1435 xqCheckers[rf][ff] = xqCheckers[EP_STATUS] & 1; // remember who is checking (if status == 1)
1437 if( board[EP_STATUS] == EP_ROYAL_LION && (board[rt][ft] == WhiteLion || board[rt][ft] == BlackLion)
1438 && (gameInfo.variant != VariantLion || board[rf][ff] != WhiteKing && board[rf][ff] != BlackKing) )
1439 cl->check++; // [HGM] lion: forbidden counterstrike against Lion equated to putting yourself in check
1443 /* If the player on move were to move from (rf, ff) to (rt, ft), would
1444 he leave himself in check? Or if rf == -1, is the player on move
1445 in check now? enPassant must be TRUE if the indicated move is an
1446 e.p. capture. The possibility of castling out of a check along the
1447 back rank is not accounted for (i.e., we still return nonzero), as
1448 this is illegal anyway. Return value is the number of times the
1449 king is in check. */
1451 CheckTest (Board board, int flags, int rf, int ff, int rt, int ft, int enPassant)
1453 CheckTestClosure cl;
1454 ChessSquare king = flags & F_WHITE_ON_MOVE ? WhiteKing : BlackKing;
1455 ChessSquare captured = EmptySquare, ep=0, trampled=0;
1456 /* Suppress warnings on uninitialized variables */
1458 if(gameInfo.variant == VariantXiangqi)
1459 king = flags & F_WHITE_ON_MOVE ? WhiteWazir : BlackWazir;
1460 if(gameInfo.variant == VariantKnightmate)
1461 king = flags & F_WHITE_ON_MOVE ? WhiteUnicorn : BlackUnicorn;
1462 if(gameInfo.variant == VariantChu) { // strictly speaking this is not needed, as Chu officially has no check
1463 int r, f, k = king, royals=0, prince = flags & F_WHITE_ON_MOVE ? WhiteMonarch : BlackMonarch;
1464 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++) {
1465 if(board[r][f] == k || board[r][f] == prince) {
1466 if(++royals > 1) return FALSE; // no check if we have two royals (ignores double captureby Lion!)
1467 king = board[r][f]; // remember hich one we had
1474 captured = board[rf][ft];
1475 board[rf][ft] = EmptySquare;
1477 captured = board[rt][ft];
1478 if(killX >= 0) { trampled = board[killY][killX]; board[killY][killX] = EmptySquare; }
1480 if(rf == DROP_RANK) board[rt][ft] = ff; else { // [HGM] drop
1481 board[rt][ft] = board[rf][ff];
1482 board[rf][ff] = EmptySquare;
1484 ep = board[EP_STATUS];
1485 if( captured == WhiteLion || captured == BlackLion ) { // [HGM] lion: Chu Lion-capture rules
1486 ChessSquare victim = killX < 0 ? EmptySquare : trampled;
1487 if( (board[rt][ft] == WhiteLion || board[rt][ft] == BlackLion) && // capturer is Lion
1488 (ff - ft > 1 || ft - ff > 1 || rf - rt > 1 || rt - rf > 1) && // captures from a distance
1489 (victim == EmptySquare || victim == WhitePawn || victim == BlackPawn) ) // no or worthless 'bridge'
1490 board[EP_STATUS] = EP_ROYAL_LION; // on distant Lion x Lion victim must not be pseudo-legally protected
1494 /* For compatibility with ICS wild 9, we scan the board in the
1495 order a1, a2, a3, ... b1, b2, ..., h8 to find the first king,
1496 and we test only whether that one is in check. */
1497 for (cl.fking = BOARD_LEFT+0; cl.fking < BOARD_RGHT; cl.fking++)
1498 for (cl.rking = 0; cl.rking < BOARD_HEIGHT; cl.rking++) {
1499 if (board[cl.rking][cl.fking] == king) {
1501 if(gameInfo.variant == VariantXiangqi) {
1502 /* [HGM] In Xiangqi opposing Kings means check as well */
1504 dir = (king >= BlackPawn) ? -1 : 1;
1505 for( i=cl.rking+dir; i>=0 && i<BOARD_HEIGHT &&
1506 board[i][cl.fking] == EmptySquare; i+=dir );
1507 if(i>=0 && i<BOARD_HEIGHT &&
1508 board[i][cl.fking] == (dir>0 ? BlackWazir : WhiteWazir) )
1511 GenPseudoLegal(board, flags ^ F_WHITE_ON_MOVE, CheckTestCallback, (VOIDSTAR) &cl, EmptySquare);
1512 if(gameInfo.variant != VariantSpartan || cl.check == 0) // in Spartan Chess go on to test if other King is checked too
1513 goto undo_move; /* 2-level break */
1520 if(rf != DROP_RANK) // [HGM] drop
1521 board[rf][ff] = board[rt][ft];
1523 board[rf][ft] = captured;
1524 board[rt][ft] = EmptySquare;
1526 if(killX >= 0) board[killY][killX] = trampled;
1527 board[rt][ft] = captured;
1529 board[EP_STATUS] = ep;
1532 return cl.fking < BOARD_RGHT ? cl.check : 1000; // [HGM] atomic: return 1000 if we have no king
1536 HasLion (Board board, int flags)
1538 int lion = F_WHITE_ON_MOVE & flags ? WhiteLion : BlackLion;
1540 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++)
1541 if(board[r][f] == lion) return 1;
1546 LegalDrop (Board board, int flags, ChessSquare piece, int rt, int ft)
1547 { // [HGM] put drop legality testing in separate routine for clarity
1549 if(appData.debugMode) fprintf(debugFP, "LegalDrop: %d @ %d,%d)\n", piece, ft, rt);
1550 if(board[rt][ft] != EmptySquare) return ImpossibleMove; // must drop to empty square
1551 n = PieceToNumber(piece);
1552 if((gameInfo.holdingsWidth == 0 || (flags & F_WHITE_ON_MOVE ? board[n][BOARD_WIDTH-1] : board[BOARD_HEIGHT-1-n][0]) != piece)
1553 && gameInfo.variant != VariantBughouse) // in bughouse we don't check for availability, because ICS doesn't always tell us
1554 return ImpossibleMove; // piece not available
1555 if(gameInfo.variant == VariantShogi) { // in Shogi lots of drops are forbidden!
1556 if((piece == WhitePawn || piece == WhiteQueen) && rt == BOARD_HEIGHT-1 ||
1557 (piece == BlackPawn || piece == BlackQueen) && rt == 0 ||
1558 piece == WhiteKnight && rt > BOARD_HEIGHT-3 ||
1559 piece == BlackKnight && rt < 2 ) return IllegalMove; // e.g. where dropped piece has no moves
1560 if(piece == WhitePawn || piece == BlackPawn) {
1561 int r, max = 1 + (BOARD_HEIGHT == 7); // two Pawns per file in Tori!
1562 for(r=1; r<BOARD_HEIGHT-1; r++)
1563 if(!(max -= (board[r][ft] == piece))) return IllegalMove; // or there already is a Pawn in file
1564 // should still test if we mate with this Pawn
1566 } else if(gameInfo.variant == VariantSChess) { // only back-rank drops
1567 if (rt != (piece < BlackPawn ? 0 : BOARD_HEIGHT-1)) return IllegalMove;
1569 if( (piece == WhitePawn || piece == BlackPawn) &&
1570 (rt == 0 || rt == BOARD_HEIGHT -1 ) )
1571 return IllegalMove; /* no pawn drops on 1st/8th */
1573 if(appData.debugMode) fprintf(debugFP, "LegalDrop: %d @ %d,%d)\n", piece, ft, rt);
1574 if (!(flags & F_IGNORE_CHECK) &&
1575 CheckTest(board, flags, DROP_RANK, piece, rt, ft, FALSE) ) return IllegalMove;
1576 return flags & F_WHITE_ON_MOVE ? WhiteDrop : BlackDrop;
1579 extern void LegalityTestCallback P((Board board, int flags, ChessMove kind,
1580 int rf, int ff, int rt, int ft,
1584 LegalityTestCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1586 register LegalityTestClosure *cl = (LegalityTestClosure *) closure;
1588 if(board[rt][ft] != EmptySquare || kind==WhiteCapturesEnPassant || kind==BlackCapturesEnPassant)
1589 cl->captures++; // [HGM] losers: count legal captures
1590 if (rf == cl->rf && ff == cl->ff && rt == cl->rt && ft == cl->ft)
1595 LegalityTest (Board board, int flags, int rf, int ff, int rt, int ft, int promoChar)
1597 LegalityTestClosure cl; ChessSquare piece, filterPiece;
1599 if(quickFlag) flags = flags & ~1 | quickFlag & 1; // [HGM] speed: in quick mode quickFlag specifies side-to-move.
1600 if(rf == DROP_RANK) return LegalDrop(board, flags, ff, rt, ft);
1601 piece = filterPiece = board[rf][ff];
1602 if(PieceToChar(piece) == '~') filterPiece = DEMOTED piece;
1604 /* [HGM] Cobra and Falcon are wildcard pieces; consider all their moves legal */
1605 /* (perhaps we should disallow moves that obviously leave us in check?) */
1606 if((piece == WhiteFalcon || piece == BlackFalcon ||
1607 piece == WhiteCobra || piece == BlackCobra) && gameInfo.variant != VariantChu)
1608 return CheckTest(board, flags, rf, ff, rt, ft, FALSE) ? IllegalMove : NormalMove;
1612 cl.rt = rFilter = rt; // [HGM] speed: filter on to-square
1613 cl.ft = fFilter = ft;
1614 cl.kind = IllegalMove;
1615 cl.captures = 0; // [HGM] losers: prepare to count legal captures.
1616 if(flags & F_MANDATORY_CAPTURE) filterPiece = EmptySquare; // [HGM] speed: do not filter in suicide, to find all captures
1617 GenLegal(board, flags, LegalityTestCallback, (VOIDSTAR) &cl, filterPiece);
1618 if((flags & F_MANDATORY_CAPTURE) && cl.captures && board[rt][ft] == EmptySquare
1619 && cl.kind != WhiteCapturesEnPassant && cl.kind != BlackCapturesEnPassant)
1620 return(IllegalMove); // [HGM] losers: if there are legal captures, non-capts are illegal
1622 if(promoChar == 'x') promoChar = NULLCHAR; // [HGM] is this ever the case?
1623 if(gameInfo.variant == VariantSChess && promoChar && promoChar != '=' && board[rf][ff] != WhitePawn && board[rf][ff] != BlackPawn) {
1624 if(board[rf][ff] < BlackPawn) { // white
1625 if(rf != 0) return IllegalMove; // must be on back rank
1626 if(!(board[VIRGIN][ff] & VIRGIN_W)) return IllegalMove; // non-virgin
1627 if(board[PieceToNumber(CharToPiece(ToUpper(promoChar)))][BOARD_WIDTH-2] == 0) return ImpossibleMove;// must be in stock
1628 if(cl.kind == WhiteHSideCastleFR && (ff == BOARD_RGHT-2 || ff == BOARD_RGHT-3)) return ImpossibleMove;
1629 if(cl.kind == WhiteASideCastleFR && (ff == BOARD_LEFT+2 || ff == BOARD_LEFT+3)) return ImpossibleMove;
1631 if(rf != BOARD_HEIGHT-1) return IllegalMove;
1632 if(!(board[VIRGIN][ff] & VIRGIN_B)) return IllegalMove; // non-virgin
1633 if(board[BOARD_HEIGHT-1-PieceToNumber(CharToPiece(ToLower(promoChar)))][1] == 0) return ImpossibleMove;
1634 if(cl.kind == BlackHSideCastleFR && (ff == BOARD_RGHT-2 || ff == BOARD_RGHT-3)) return ImpossibleMove;
1635 if(cl.kind == BlackASideCastleFR && (ff == BOARD_LEFT+2 || ff == BOARD_LEFT+3)) return ImpossibleMove;
1638 if(gameInfo.variant == VariantChu) {
1639 if(cl.kind != NormalMove || promoChar == NULLCHAR || promoChar == '=') return cl.kind;
1640 if(promoChar != '+')
1641 return CharToPiece(promoChar) == EmptySquare ? ImpossibleMove : IllegalMove;
1642 if(PieceToChar(CHUPROMOTED board[rf][ff]) != '+') return ImpossibleMove;
1643 return flags & F_WHITE_ON_MOVE ? WhitePromotion : BlackPromotion;
1645 if(gameInfo.variant == VariantShogi) {
1646 /* [HGM] Shogi promotions. '=' means defer */
1647 if(rf != DROP_RANK && cl.kind == NormalMove) {
1648 ChessSquare piece = board[rf][ff];
1650 if(promoChar == PieceToChar(BlackQueen)) promoChar = NULLCHAR; /* [HGM] Kludge */
1651 if(promoChar == 'd' && (piece == WhiteRook || piece == BlackRook) ||
1652 promoChar == 'h' && (piece == WhiteBishop || piece == BlackBishop) ||
1653 promoChar == 'g' && (piece <= WhiteFerz || piece <= BlackFerz && piece >= BlackPawn) )
1654 promoChar = '+'; // allowed ICS notations
1655 if(appData.debugMode)fprintf(debugFP,"SHOGI promoChar = %c\n", promoChar ? promoChar : '-');
1656 if(promoChar != NULLCHAR && promoChar != '+' && promoChar != '=')
1657 return CharToPiece(promoChar) == EmptySquare ? ImpossibleMove : IllegalMove;
1658 else if(flags & F_WHITE_ON_MOVE) {
1659 if( (int) piece < (int) WhiteWazir &&
1660 (rf >= BOARD_HEIGHT - BOARD_HEIGHT/3 || rt >= BOARD_HEIGHT - BOARD_HEIGHT/3) ) {
1661 if( (piece == WhitePawn || piece == WhiteQueen) && rt > BOARD_HEIGHT-2 ||
1662 piece == WhiteKnight && rt > BOARD_HEIGHT-3) /* promotion mandatory */
1663 cl.kind = promoChar == '=' ? IllegalMove : WhitePromotion;
1664 else /* promotion optional, default is defer */
1665 cl.kind = promoChar == '+' ? WhitePromotion : WhiteNonPromotion;
1666 } else cl.kind = promoChar == '+' ? IllegalMove : NormalMove;
1668 if( (int) piece < (int) BlackWazir && (rf < BOARD_HEIGHT/3 || rt < BOARD_HEIGHT/3) ) {
1669 if( (piece == BlackPawn || piece == BlackQueen) && rt < 1 ||
1670 piece == BlackKnight && rt < 2 ) /* promotion obligatory */
1671 cl.kind = promoChar == '=' ? IllegalMove : BlackPromotion;
1672 else /* promotion optional, default is defer */
1673 cl.kind = promoChar == '+' ? BlackPromotion : BlackNonPromotion;
1674 } else cl.kind = promoChar == '+' ? IllegalMove : NormalMove;
1678 if (promoChar != NULLCHAR) {
1679 if(cl.kind == NormalMove && promoChar == '+') { // allow shogi-style promotion is pieceToChar specifies them
1680 ChessSquare piece = board[rf][ff];
1681 if(piece < BlackPawn ? piece > WhiteMan : piece > BlackMan) return ImpossibleMove; // already promoted
1682 // should test if in zone, really
1683 if(gameInfo.variant == VariantChuChess && (piece == WhiteKnight || piece == BlackKnight) && HasLion(board, flags))
1685 if(PieceToChar(PROMOTED piece) == '+') return flags & F_WHITE_ON_MOVE ? WhitePromotion : BlackPromotion;
1687 if(promoChar == '=') cl.kind = IllegalMove; else // [HGM] shogi: no deferred promotion outside Shogi
1688 if (cl.kind == WhitePromotion || cl.kind == BlackPromotion) {
1689 ChessSquare piece = CharToPiece(flags & F_WHITE_ON_MOVE ? ToUpper(promoChar) : ToLower(promoChar));
1690 if(piece == EmptySquare)
1691 cl.kind = ImpossibleMove; // non-existing piece
1692 if(gameInfo.variant == VariantChuChess && promoChar == 'l' && HasLion(board, flags)) {
1693 cl.kind = IllegalMove; // no two Lions
1694 } else if(gameInfo.variant == VariantSpartan && cl.kind == BlackPromotion ) {
1695 if(promoChar != PieceToChar(BlackKing)) {
1696 if(CheckTest(board, flags, rf, ff, rt, ft, FALSE)) cl.kind = IllegalMove; // [HGM] spartan: only promotion to King was possible
1697 if(piece == BlackLance) cl.kind = ImpossibleMove;
1698 } else { // promotion to King allowed only if we do not have two yet
1699 int r, f, kings = 0;
1700 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++) kings += (board[r][f] == BlackKing);
1701 if(kings == 2) cl.kind = IllegalMove;
1703 } else if(piece == WhitePawn && rt == BOARD_HEIGHT-1 ||
1704 piece == BlackPawn && rt == 0) cl.kind = IllegalMove; // cannot stay Pawn on last rank in any variant
1705 else if((piece == WhiteUnicorn || piece == BlackUnicorn) && gameInfo.variant == VariantKnightmate)
1706 cl.kind = IllegalMove; // promotion to Royal Knight not allowed
1707 else if((piece == WhiteKing || piece == BlackKing) && gameInfo.variant != VariantSuicide && gameInfo.variant != VariantGiveaway)
1708 cl.kind = IllegalMove; // promotion to King usually not allowed
1710 cl.kind = IllegalMove;
1720 extern void MateTestCallback P((Board board, int flags, ChessMove kind,
1721 int rf, int ff, int rt, int ft,
1725 MateTestCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1727 register MateTestClosure *cl = (MateTestClosure *) closure;
1732 /* Return MT_NONE, MT_CHECK, MT_CHECKMATE, or MT_STALEMATE */
1734 MateTest (Board board, int flags)
1737 int inCheck, r, f, myPieces=0, hisPieces=0, nrKing=0;
1738 ChessSquare king = flags & F_WHITE_ON_MOVE ? WhiteKing : BlackKing;
1740 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++) {
1741 // [HGM] losers: Count pieces and kings, to detect other unorthodox winning conditions
1742 nrKing += (board[r][f] == king); // stm has king
1743 if( board[r][f] != EmptySquare ) {
1744 if((int)board[r][f] <= (int)king && (int)board[r][f] >= (int)king - (int)WhiteKing + (int)WhitePawn)
1749 switch(gameInfo.variant) { // [HGM] losers: extinction wins
1750 case VariantShatranj:
1751 if(hisPieces == 1) return myPieces > 1 ? MT_BARE : MT_DRAW;
1755 if(nrKing == 0) return MT_NOKING;
1758 if(myPieces == 1) return MT_BARE;
1761 inCheck = GenLegal(board, flags, MateTestCallback, (VOIDSTAR) &cl, EmptySquare);
1762 // [HGM] 3check: yet to do!
1764 return inCheck ? MT_CHECK : MT_NONE;
1766 if(gameInfo.holdingsWidth && gameInfo.variant != VariantSuper && gameInfo.variant != VariantGreat
1767 && gameInfo.variant != VariantSChess && gameInfo.variant != VariantGrand) { // drop game
1768 int r, f, n, holdings = flags & F_WHITE_ON_MOVE ? BOARD_WIDTH-1 : 0;
1769 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++) if(board[r][f] == EmptySquare) // all empty squares
1770 for(n=0; n<BOARD_HEIGHT; n++) // all pieces in hand
1771 if(board[n][holdings] != EmptySquare) {
1772 int moveType = LegalDrop(board, flags, board[n][holdings], r, f);
1773 if(moveType == WhiteDrop || moveType == BlackDrop) return (inCheck ? MT_CHECK : MT_NONE); // we have legal drop
1776 if(gameInfo.variant == VariantSuicide) // [HGM] losers: always stalemate, since no check, but result varies
1777 return myPieces == hisPieces ? MT_STALEMATE :
1778 myPieces > hisPieces ? MT_STAINMATE : MT_STEALMATE;
1779 else if(gameInfo.variant == VariantLosers) return inCheck ? MT_TRICKMATE : MT_STEALMATE;
1780 else if(gameInfo.variant == VariantGiveaway) return MT_STEALMATE; // no check exists, stalemated = win
1782 return inCheck ? MT_CHECKMATE
1783 : (gameInfo.variant == VariantXiangqi || gameInfo.variant == VariantShatranj || IS_SHOGI(gameInfo.variant)) ?
1784 MT_STAINMATE : MT_STALEMATE;
1789 extern void DisambiguateCallback P((Board board, int flags, ChessMove kind,
1790 int rf, int ff, int rt, int ft,
1794 DisambiguateCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1796 register DisambiguateClosure *cl = (DisambiguateClosure *) closure;
1797 int wildCard = FALSE; ChessSquare piece = board[rf][ff];
1799 // [HGM] wild: for wild-card pieces rt and rf are dummies
1800 if(piece == WhiteFalcon || piece == BlackFalcon ||
1801 piece == WhiteCobra || piece == BlackCobra)
1804 if ((cl->pieceIn == EmptySquare || cl->pieceIn == board[rf][ff]
1805 || PieceToChar(board[rf][ff]) == '~'
1806 && cl->pieceIn == (ChessSquare)(DEMOTED board[rf][ff])
1808 (cl->rfIn == -1 || cl->rfIn == rf) &&
1809 (cl->ffIn == -1 || cl->ffIn == ff) &&
1810 (cl->rtIn == -1 || cl->rtIn == rt || wildCard) &&
1811 (cl->ftIn == -1 || cl->ftIn == ft || wildCard)) {
1814 if(cl->count == 1 || board[rt][ft] != EmptySquare) {
1815 // [HGM] oneclick: if multiple moves, be sure we remember capture
1816 cl->piece = board[rf][ff];
1819 cl->rt = wildCard ? cl->rtIn : rt;
1820 cl->ft = wildCard ? cl->ftIn : ft;
1823 cl->captures += (board[rt][ft] != EmptySquare); // [HGM] oneclick: count captures
1828 Disambiguate (Board board, int flags, DisambiguateClosure *closure)
1830 int illegal = 0; char c = closure->promoCharIn;
1832 if(quickFlag) flags = flags & ~1 | quickFlag & 1; // [HGM] speed: in quick mode quickFlag specifies side-to-move.
1833 closure->count = closure->captures = 0;
1834 closure->rf = closure->ff = closure->rt = closure->ft = 0;
1835 closure->kind = ImpossibleMove;
1836 rFilter = closure->rtIn; // [HGM] speed: only consider moves to given to-square
1837 fFilter = closure->ftIn;
1838 if(quickFlag) { // [HGM] speed: try without check test first, because if that is not ambiguous, we are happy
1839 GenLegal(board, flags|F_IGNORE_CHECK, DisambiguateCallback, (VOIDSTAR) closure, closure->pieceIn);
1840 if(closure->count > 1) { // gamble did not pay off. retry with check test to resolve ambiguity
1841 closure->count = closure->captures = 0;
1842 closure->rf = closure->ff = closure->rt = closure->ft = 0;
1843 closure->kind = ImpossibleMove;
1844 GenLegal(board, flags, DisambiguateCallback, (VOIDSTAR) closure, closure->pieceIn); // [HGM] speed: only pieces of requested type
1847 GenLegal(board, flags, DisambiguateCallback, (VOIDSTAR) closure, closure->pieceIn); // [HGM] speed: only pieces of requested type
1848 if (closure->count == 0) {
1849 /* See if it's an illegal move due to check */
1851 GenLegal(board, flags|F_IGNORE_CHECK, DisambiguateCallback, (VOIDSTAR) closure, closure->pieceIn);
1852 if (closure->count == 0) {
1853 /* No, it's not even that */
1854 if(!appData.testLegality && closure->pieceIn != EmptySquare) {
1855 int f, r; // if there is only a single piece of the requested type on the board, use that
1856 closure->rt = closure->rtIn, closure->ft = closure->ftIn;
1857 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++)
1858 if(board[r][f] == closure->pieceIn) closure->count++, closure->rf = r, closure->ff = f;
1859 if(closure->count > 1) illegal = 0; // ambiguous
1861 if(closure->count == 0) {
1862 if (appData.debugMode) { int i, j;
1863 for(i=BOARD_HEIGHT-1; i>=0; i--) {
1864 for(j=0; j<BOARD_WIDTH; j++)
1865 fprintf(debugFP, "%3d", (int) board[i][j]);
1866 fprintf(debugFP, "\n");
1874 if (c == 'x') c = NULLCHAR; // get rid of any 'x' (which should never happen?)
1875 if(gameInfo.variant == VariantSChess && c && c != '=' && closure->piece != WhitePawn && closure->piece != BlackPawn) {
1876 if(closure->piece < BlackPawn) { // white
1877 if(closure->rf != 0) closure->kind = IllegalMove; // must be on back rank
1878 if(!(board[VIRGIN][closure->ff] & VIRGIN_W)) closure->kind = IllegalMove; // non-virgin
1879 if(board[PieceToNumber(CharToPiece(ToUpper(c)))][BOARD_WIDTH-2] == 0) closure->kind = ImpossibleMove;// must be in stock
1880 if(closure->kind == WhiteHSideCastleFR && (closure->ff == BOARD_RGHT-2 || closure->ff == BOARD_RGHT-3)) closure->kind = ImpossibleMove;
1881 if(closure->kind == WhiteASideCastleFR && (closure->ff == BOARD_LEFT+2 || closure->ff == BOARD_LEFT+3)) closure->kind = ImpossibleMove;
1883 if(closure->rf != BOARD_HEIGHT-1) closure->kind = IllegalMove;
1884 if(!(board[VIRGIN][closure->ff] & VIRGIN_B)) closure->kind = IllegalMove; // non-virgin
1885 if(board[BOARD_HEIGHT-1-PieceToNumber(CharToPiece(ToLower(c)))][1] == 0) closure->kind = ImpossibleMove;
1886 if(closure->kind == BlackHSideCastleFR && (closure->ff == BOARD_RGHT-2 || closure->ff == BOARD_RGHT-3)) closure->kind = ImpossibleMove;
1887 if(closure->kind == BlackASideCastleFR && (closure->ff == BOARD_LEFT+2 || closure->ff == BOARD_LEFT+3)) closure->kind = ImpossibleMove;
1890 if(gameInfo.variant == VariantChu) {
1891 if(c == '+') closure->kind = (flags & F_WHITE_ON_MOVE ? WhitePromotion : BlackPromotion); // for now, accept any
1893 if(gameInfo.variant == VariantShogi) {
1894 /* [HGM] Shogi promotions. On input, '=' means defer, '+' promote. Afterwards, c is set to '+' for promotions, NULL other */
1895 if(closure->rfIn != DROP_RANK && closure->kind == NormalMove) {
1896 ChessSquare piece = closure->piece;
1897 if (c == 'd' && (piece == WhiteRook || piece == BlackRook) ||
1898 c == 'h' && (piece == WhiteBishop || piece == BlackBishop) ||
1899 c == 'g' && (piece <= WhiteFerz || piece <= BlackFerz && piece >= BlackPawn) )
1900 c = '+'; // allowed ICS notations
1901 if(c != NULLCHAR && c != '+' && c != '=') closure->kind = IllegalMove; // otherwise specifying a piece is illegal
1902 else if(flags & F_WHITE_ON_MOVE) {
1903 if( (int) piece < (int) WhiteWazir &&
1904 (closure->rf >= BOARD_HEIGHT-(BOARD_HEIGHT/3) || closure->rt >= BOARD_HEIGHT-(BOARD_HEIGHT/3)) ) {
1905 if( (piece == WhitePawn || piece == WhiteQueen) && closure->rt > BOARD_HEIGHT-2 ||
1906 piece == WhiteKnight && closure->rt > BOARD_HEIGHT-3) /* promotion mandatory */
1907 closure->kind = c == '=' ? IllegalMove : WhitePromotion;
1908 else /* promotion optional, default is defer */
1909 closure->kind = c == '+' ? WhitePromotion : WhiteNonPromotion;
1910 } else closure->kind = c == '+' ? IllegalMove : NormalMove;
1912 if( (int) piece < (int) BlackWazir && (closure->rf < BOARD_HEIGHT/3 || closure->rt < BOARD_HEIGHT/3) ) {
1913 if( (piece == BlackPawn || piece == BlackQueen) && closure->rt < 1 ||
1914 piece == BlackKnight && closure->rt < 2 ) /* promotion obligatory */
1915 closure->kind = c == '=' ? IllegalMove : BlackPromotion;
1916 else /* promotion optional, default is defer */
1917 closure->kind = c == '+' ? BlackPromotion : BlackNonPromotion;
1918 } else closure->kind = c == '+' ? IllegalMove : NormalMove;
1921 if(closure->kind == WhitePromotion || closure->kind == BlackPromotion) c = '+'; else
1922 if(closure->kind == WhiteNonPromotion || closure->kind == BlackNonPromotion) c = '=';
1924 if (closure->kind == WhitePromotion || closure->kind == BlackPromotion) {
1925 if(c == NULLCHAR) { // missing promoChar on mandatory promotion; use default for variant
1926 if(gameInfo.variant == VariantShatranj || gameInfo.variant == VariantCourier ||
1927 gameInfo.variant == VariantMakruk || gameInfo.variant == VariantASEAN)
1928 c = PieceToChar(BlackFerz);
1929 else if(gameInfo.variant == VariantGreat)
1930 c = PieceToChar(BlackMan);
1931 else if(gameInfo.variant == VariantGrand)
1932 closure->kind = closure->rt != 0 && closure->rt != BOARD_HEIGHT-1 ? NormalMove : AmbiguousMove; // no default in Grand Chess
1934 c = PieceToChar(BlackQueen);
1935 } else if(c == '=') closure->kind = IllegalMove; // no deferral outside Shogi
1936 else if(c == 'l' && gameInfo.variant == VariantChuChess && HasLion(board, flags)) closure->kind = IllegalMove;
1937 } else if (c == '+') { // '+' outside shogi, check if pieceToCharTable enabled it
1938 ChessSquare p = closure->piece;
1939 if(p > WhiteMan && p < BlackPawn || p > BlackMan || PieceToChar(PROMOTED p) != '+')
1940 closure->kind = ImpossibleMove; // used on non-promotable piece
1941 else if(gameInfo.variant == VariantChuChess && HasLion(board, flags)) closure->kind = IllegalMove;
1942 } else if (c != NULLCHAR) closure->kind = IllegalMove;
1944 closure->promoChar = ToLower(c); // this can be NULLCHAR! Note we keep original promoChar even if illegal.
1945 if(c != '+' && c != '=' && c != NULLCHAR && CharToPiece(flags & F_WHITE_ON_MOVE ? ToUpper(c) : ToLower(c)) == EmptySquare)
1946 closure->kind = ImpossibleMove; // but we cannot handle non-existing piece types!
1947 if (closure->count > 1) {
1948 closure->kind = AmbiguousMove;
1951 /* Note: If more than one illegal move matches, but no legal
1952 moves, we return IllegalMove, not AmbiguousMove. Caller
1953 can look at closure->count to detect this.
1955 closure->kind = IllegalMove;
1969 } CoordsToAlgebraicClosure;
1971 extern void CoordsToAlgebraicCallback P((Board board, int flags,
1972 ChessMove kind, int rf, int ff,
1973 int rt, int ft, VOIDSTAR closure));
1976 CoordsToAlgebraicCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1978 register CoordsToAlgebraicClosure *cl =
1979 (CoordsToAlgebraicClosure *) closure;
1981 if ((rt == cl->rt && ft == cl->ft || rt == rf && ft == ff) && // [HGM] null move matches any toSquare
1982 (board[rf][ff] == cl->piece
1983 || PieceToChar(board[rf][ff]) == '~' &&
1984 (ChessSquare) (DEMOTED board[rf][ff]) == cl->piece)
1988 cl->kind = kind; /* this is the move we want */
1990 cl->file++; /* need file to rule out this move */
1994 cl->rank++; /* need rank to rule out this move */
1996 cl->either++; /* rank or file will rule out this move */
2002 /* Convert coordinates to normal algebraic notation.
2003 promoChar must be NULLCHAR or 'x' if not a promotion.
2006 CoordsToAlgebraic (Board board, int flags, int rf, int ff, int rt, int ft, int promoChar, char out[MOVE_LEN])
2010 char *outp = out, c, capture;
2011 CoordsToAlgebraicClosure cl;
2013 if (rf == DROP_RANK) {
2014 if(ff == EmptySquare) { strncpy(outp, "--",3); return NormalMove; } // [HGM] pass
2015 /* Bughouse piece drop */
2016 *outp++ = ToUpper(PieceToChar((ChessSquare) ff));
2021 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2023 return (flags & F_WHITE_ON_MOVE) ? WhiteDrop : BlackDrop;
2026 if (promoChar == 'x') promoChar = NULLCHAR;
2027 piece = board[rf][ff];
2028 if(PieceToChar(piece)=='~') piece = (ChessSquare)(DEMOTED piece);
2033 kind = LegalityTest(board, flags, rf, ff, rt, ft, promoChar);
2034 if (kind == IllegalMove && !(flags&F_IGNORE_CHECK)) {
2035 /* Keep short notation if move is illegal only because it
2036 leaves the player in check, but still return IllegalMove */
2037 kind = LegalityTest(board, flags|F_IGNORE_CHECK, rf, ff, rt, ft, promoChar);
2038 if (kind == IllegalMove) break;
2043 capture = board[rt][ft] != EmptySquare || kind == WhiteCapturesEnPassant || kind == BlackCapturesEnPassant;
2044 if (ff == ft && !capture) { /* [HGM] Xiangqi has straight noncapts! */
2045 /* Non-capture; use style "e5" */
2048 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2050 /* Capture; use style "exd5" */
2052 *outp++ = 'x'; /* [HGM] Xiangqi has sideway noncaptures across river! */
2056 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2058 /* Use promotion suffix style "=Q" */
2060 if (promoChar != NULLCHAR) {
2061 if(IS_SHOGI(gameInfo.variant)) {
2062 /* [HGM] ... but not in Shogi! */
2063 *outp++ = promoChar == '=' ? '=' : '+';
2066 *outp++ = ToUpper(promoChar);
2075 /* Fabien moved code: FRC castling first (if KxR), wild castling second */
2076 /* Code added by Tord: FRC castling. */
2077 if((piece == WhiteKing && board[rt][ft] == WhiteRook) ||
2078 (piece == BlackKing && board[rt][ft] == BlackRook)) {
2080 safeStrCpy(out, "O-O", MOVE_LEN);
2082 safeStrCpy(out, "O-O-O", MOVE_LEN);
2083 return LegalityTest(board, flags, rf, ff, rt, ft, promoChar);
2085 /* End of code added by Tord */
2086 /* Test for castling or ICS wild castling */
2087 /* Use style "O-O" (oh-oh) for PGN compatibility */
2088 else if (rf == rt &&
2089 rf == ((piece == WhiteKing) ? 0 : BOARD_HEIGHT-1) &&
2090 (ft - ff > 1 || ff - ft > 1) && // No castling if legal King move (on narrow boards!)
2091 ((ff == BOARD_WIDTH>>1 && (ft == BOARD_LEFT+2 || ft == BOARD_RGHT-2)) ||
2092 (ff == (BOARD_WIDTH-1)>>1 && (ft == BOARD_LEFT+1 || ft == BOARD_RGHT-3)))) {
2093 if(ft==BOARD_LEFT+1 || ft==BOARD_RGHT-2)
2094 snprintf(out, MOVE_LEN, "O-O%c%c", promoChar ? '/' : 0, ToUpper(promoChar));
2096 snprintf(out, MOVE_LEN, "O-O-O%c%c", promoChar ? '/' : 0, ToUpper(promoChar));
2098 /* This notation is always unambiguous, unless there are
2099 kings on both the d and e files, with "wild castling"
2100 possible for the king on the d file and normal castling
2101 possible for the other. ICS rules for wild 9
2102 effectively make castling illegal for either king in
2103 this situation. So I am not going to worry about it;
2104 I'll just generate an ambiguous O-O in this case.
2106 return LegalityTest(board, flags, rf, ff, rt, ft, promoChar);
2109 /* else fall through */
2114 cl.rt = rFilter = rt; // [HGM] speed: filter on to-square
2115 cl.ft = fFilter = ft;
2117 cl.kind = IllegalMove;
2118 cl.rank = cl.file = cl.either = 0;
2119 c = PieceToChar(piece) ;
2120 GenLegal(board, flags, CoordsToAlgebraicCallback, (VOIDSTAR) &cl, c!='~' ? piece : (DEMOTED piece)); // [HGM] speed
2122 if (cl.kind == IllegalMove && !(flags&F_IGNORE_CHECK)) {
2123 /* Generate pretty moves for moving into check, but
2124 still return IllegalMove.
2126 GenLegal(board, flags|F_IGNORE_CHECK, CoordsToAlgebraicCallback, (VOIDSTAR) &cl, c!='~' ? piece : (DEMOTED piece));
2127 if (cl.kind == IllegalMove) break;
2128 cl.kind = IllegalMove;
2131 /* Style is "Nf3" or "Nxf7" if this is unambiguous,
2132 else "Ngf3" or "Ngxf7",
2133 else "N1f3" or "N5xf7",
2134 else "Ng1f3" or "Ng5xf7".
2136 if( c == '~' || c == '+') {
2137 /* [HGM] print nonexistent piece as its demoted version */
2138 piece = (ChessSquare) (DEMOTED piece - 11*(gameInfo.variant == VariantChu));
2140 if(c=='+') *outp++ = c;
2141 *outp++ = ToUpper(PieceToChar(piece));
2143 if (cl.file || (cl.either && !cl.rank)) {
2149 else { *outp++ = (rf+ONE-'0')/10 + '0';*outp++ = (rf+ONE-'0')%10 + '0'; }
2152 if(board[rt][ft] != EmptySquare)
2158 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2159 if (IS_SHOGI(gameInfo.variant)) {
2160 /* [HGM] in Shogi non-pawns can promote */
2161 *outp++ = promoChar; // Don't bother to correct move type, return value is never used!
2163 else if (gameInfo.variant == VariantChuChess && promoChar ||
2164 gameInfo.variant != VariantSuper && promoChar &&
2165 (piece == WhiteLance || piece == BlackLance) ) { // Lance sometimes represents Pawn
2167 *outp++ = ToUpper(promoChar);
2169 else if (gameInfo.variant == VariantSChess && promoChar) { // and in S-Chess we have gating
2171 *outp++ = ToUpper(promoChar);
2177 /* Moving a nonexistent piece */
2181 /* Not a legal move, even ignoring check.
2182 If there was a piece on the from square,
2183 use style "Ng1g3" or "Ng1xe8";
2184 if there was a pawn or nothing (!),
2185 use style "g1g3" or "g1xe8". Use "x"
2186 if a piece was on the to square, even
2187 a piece of the same color.
2191 if (piece != EmptySquare && piece != WhitePawn && piece != BlackPawn) {
2193 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<=BOARD_RGHT; f++)
2194 c += (board[r][f] == piece); // count on-board pieces of given type
2195 *outp++ = ToUpper(PieceToChar(piece));
2197 if(c != 1) { // [HGM] but if there is only one piece of the mentioned type, no from-square, thank you!
2201 else { *outp++ = (rf+ONE-'0')/10 + '0';*outp++ = (rf+ONE-'0')%10 + '0'; }
2203 if (board[rt][ft] != EmptySquare) *outp++ = 'x';
2207 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2208 /* Use promotion suffix style "=Q" */
2209 if (promoChar != NULLCHAR && promoChar != 'x') {
2211 *outp++ = ToUpper(promoChar);
2218 // [HGM] XQ: the following code serves to detect perpetual chasing (Asian rules)
2227 // I guess the following variables logically belong in the closure too, but I was too lazy and used globals
2229 int preyStackPointer, chaseStackPointer;
2232 unsigned char rf, ff, rt, ft;
2236 unsigned char rank, file;
2242 // there are three new callbacks for use with GenLegal: for adding captures, deleting them, and finding a recapture
2244 extern void AtacksCallback P((Board board, int flags, ChessMove kind,
2245 int rf, int ff, int rt, int ft,
2249 AttacksCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
2250 { // For adding captures that can lead to chase indictment to the chaseStack
2251 if(board[rt][ft] == EmptySquare) return; // non-capture
2252 if(board[rt][ft] == WhitePawn && rt < BOARD_HEIGHT/2) return; // Pawn before river can be chased
2253 if(board[rt][ft] == BlackPawn && rt >= BOARD_HEIGHT/2) return; // Pawn before river can be chased
2254 if(board[rf][ff] == WhitePawn || board[rf][ff] == BlackPawn) return; // Pawns are allowed to chase
2255 if(board[rf][ff] == WhiteWazir || board[rf][ff] == BlackWazir) return; // King is allowed to chase
2256 // move cannot be excluded from being a chase trivially (based on attacker and victim); save it on chaseStack
2257 chaseStack[chaseStackPointer].rf = rf;
2258 chaseStack[chaseStackPointer].ff = ff;
2259 chaseStack[chaseStackPointer].rt = rt;
2260 chaseStack[chaseStackPointer].ft = ft;
2261 chaseStackPointer++;
2264 extern void ExistingAtacksCallback P((Board board, int flags, ChessMove kind,
2265 int rf, int ff, int rt, int ft,
2269 ExistingAttacksCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
2270 { // for removing pre-exsting captures from the chaseStack, to be left with newly created ones
2272 register ChaseClosure *cl = (ChaseClosure *) closure; //closure tells us the move played in the repeat loop
2274 if(board[rt][ft] == EmptySquare) return; // no capture
2275 if(rf == cl->rf && ff == cl->ff) { // attacks with same piece from new position are not considered new
2276 rf = cl->rt; ff = cl->ft; // doctor their fromSquare so they will be recognized in chaseStack
2278 // search move in chaseStack, and delete it if it occurred there (as we know now it is not a new capture)
2279 for(i=0; i<chaseStackPointer; i++) {
2280 if(chaseStack[i].rf == rf && chaseStack[i].ff == ff &&
2281 chaseStack[i].rt == rt && chaseStack[i].ft == ft ) {
2282 // move found on chaseStack, delete it by overwriting with move popped from top of chaseStack
2283 chaseStack[i] = chaseStack[--chaseStackPointer];
2289 extern void ProtectedCallback P((Board board, int flags, ChessMove kind,
2290 int rf, int ff, int rt, int ft,
2294 ProtectedCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
2295 { // for determining if a piece (given through the closure) is protected
2296 register ChaseClosure *cl = (ChaseClosure *) closure; // closure tells us where to recapture
2298 if(rt == cl->rt && ft == cl->ft) cl->recaptures++; // count legal recaptures to this square
2299 if(appData.debugMode && board[rt][ft] != EmptySquare)
2300 fprintf(debugFP, "try %c%c%c%c=%d\n", ff+AAA, rf+ONE,ft+AAA, rt+ONE, cl->recaptures);
2303 extern char moveList[MAX_MOVES][MOVE_LEN];
2306 PerpetualChase (int first, int last)
2307 { // this routine detects if the side to move in the 'first' position is perpetually chasing (when not checking)
2310 ChessSquare captured;
2312 preyStackPointer = 0; // clear stack of chased pieces
2313 for(i=first; i<last; i+=2) { // for all positions with same side to move
2314 if(appData.debugMode) fprintf(debugFP, "judge position %i\n", i);
2315 chaseStackPointer = 0; // clear stack that is going to hold possible chases
2316 // determine all captures possible after the move, and put them on chaseStack
2317 GenLegal(boards[i+1], PosFlags(i), AttacksCallback, &cl, EmptySquare);
2318 if(appData.debugMode) { int n;
2319 for(n=0; n<chaseStackPointer; n++)
2320 fprintf(debugFP, "%c%c%c%c ", chaseStack[n].ff+AAA, chaseStack[n].rf+ONE,
2321 chaseStack[n].ft+AAA, chaseStack[n].rt+ONE);
2322 fprintf(debugFP, ": all capts\n");
2324 // determine all captures possible before the move, and delete them from chaseStack
2325 cl.rf = moveList[i][1]-ONE; // prepare closure to pass move that led from i to i+1
2326 cl.ff = moveList[i][0]-AAA+BOARD_LEFT;
2327 cl.rt = moveList[i][3]-ONE;
2328 cl.ft = moveList[i][2]-AAA+BOARD_LEFT;
2329 CopyBoard(xqCheckers, nullBoard); xqCheckers[EP_STATUS] = 1; // giant kludge to make GenLegal ignore pre-existing checks
2330 GenLegal(boards[i], PosFlags(i), ExistingAttacksCallback, &cl, EmptySquare);
2331 xqCheckers[EP_STATUS] = 0; // disable the generation of quasi-legal moves again
2332 if(appData.debugMode) { int n;
2333 for(n=0; n<chaseStackPointer; n++)
2334 fprintf(debugFP, "%c%c%c%c ", chaseStack[n].ff+AAA, chaseStack[n].rf+ONE,
2335 chaseStack[n].ft+AAA, chaseStack[n].rt+ONE);
2336 fprintf(debugFP, ": new capts after %c%c%c%c\n", cl.ff+AAA, cl.rf+ONE, cl.ft+AAA, cl.rt+ONE);
2338 // chaseSack now contains all captures made possible by the move
2339 for(j=0; j<chaseStackPointer; j++) { // run through chaseStack to identify true chases
2340 int attacker = (int)boards[i+1][chaseStack[j].rf][chaseStack[j].ff];
2341 int victim = (int)boards[i+1][chaseStack[j].rt][chaseStack[j].ft];
2343 if(attacker >= (int) BlackPawn) attacker = BLACK_TO_WHITE attacker; // convert to white, as piecee type
2344 if(victim >= (int) BlackPawn) victim = BLACK_TO_WHITE victim;
2346 if((attacker == WhiteKnight || attacker == WhiteCannon) && victim == WhiteRook)
2347 continue; // C or H attack on R is always chase; leave on chaseStack
2349 if(attacker == victim) {
2350 if(LegalityTest(boards[i+1], PosFlags(i+1), chaseStack[j].rt,
2351 chaseStack[j].ft, chaseStack[j].rf, chaseStack[j].ff, NULLCHAR) == NormalMove) {
2352 // we can capture back with equal piece, so this is no chase but a sacrifice
2353 chaseStack[j] = chaseStack[--chaseStackPointer]; // delete the capture from the chaseStack
2354 j--; /* ! */ continue;
2359 // the attack is on a lower piece, or on a pinned or blocked equal one
2360 CopyBoard(xqCheckers, nullBoard); xqCheckers[EP_STATUS] = 1;
2361 CheckTest(boards[i+1], PosFlags(i+1), -1, -1, -1, -1, FALSE); // if we deliver check with our move, the checkers get marked
2362 // test if the victim is protected by a true protector. First make the capture.
2363 captured = boards[i+1][chaseStack[j].rt][chaseStack[j].ft];
2364 boards[i+1][chaseStack[j].rt][chaseStack[j].ft] = boards[i+1][chaseStack[j].rf][chaseStack[j].ff];
2365 boards[i+1][chaseStack[j].rf][chaseStack[j].ff] = EmptySquare;
2366 // Then test if the opponent can recapture
2367 cl.recaptures = 0; // prepare closure to pass recapture square and count moves to it
2368 cl.rt = chaseStack[j].rt;
2369 cl.ft = chaseStack[j].ft;
2370 if(appData.debugMode) {
2371 fprintf(debugFP, "test if we can recapture %c%c\n", cl.ft+AAA, cl.rt+ONE);
2373 xqCheckers[EP_STATUS] = 2; // causes GenLegal to ignore the checks we delivered with the move, in real life evaded before we captured
2374 GenLegal(boards[i+1], PosFlags(i+1), ProtectedCallback, &cl, EmptySquare); // try all moves
2375 xqCheckers[EP_STATUS] = 0; // disable quasi-legal moves again
2376 // unmake the capture
2377 boards[i+1][chaseStack[j].rf][chaseStack[j].ff] = boards[i+1][chaseStack[j].rt][chaseStack[j].ft];
2378 boards[i+1][chaseStack[j].rt][chaseStack[j].ft] = captured;
2379 // if a recapture was found, piece is protected, and we are not chasing it.
2380 if(cl.recaptures) { // attacked piece was defended by true protector, no chase
2381 chaseStack[j] = chaseStack[--chaseStackPointer]; // so delete from chaseStack
2385 // chaseStack now contains all moves that chased
2386 if(appData.debugMode) { int n;
2387 for(n=0; n<chaseStackPointer; n++)
2388 fprintf(debugFP, "%c%c%c%c ", chaseStack[n].ff+AAA, chaseStack[n].rf+ONE,
2389 chaseStack[n].ft+AAA, chaseStack[n].rt+ONE);
2390 fprintf(debugFP, ": chases\n");
2392 if(i == first) { // copy all people chased by first move of repeat cycle to preyStack
2393 for(j=0; j<chaseStackPointer; j++) {
2394 preyStack[j].rank = chaseStack[j].rt;
2395 preyStack[j].file = chaseStack[j].ft;
2397 preyStackPointer = chaseStackPointer;
2400 for(j=0; j<chaseStackPointer; j++) {
2401 for(k=0; k<preyStackPointer; k++) {
2402 // search the victim of each chase move on the preyStack (first occurrence)
2403 if(chaseStack[j].ft == preyStack[k].file && chaseStack[j].rt == preyStack[k].rank ) {
2404 if(k < tail) break; // piece was already identified as still being chased
2405 preyStack[preyStackPointer] = preyStack[tail]; // move chased piece to bottom part of preyStack
2406 preyStack[tail] = preyStack[k]; // by swapping
2407 preyStack[k] = preyStack[preyStackPointer];
2413 preyStackPointer = tail; // keep bottom part of preyStack, popping pieces unchased on move i.
2414 if(appData.debugMode) { int n;
2415 for(n=0; n<preyStackPointer; n++)
2416 fprintf(debugFP, "%c%c ", preyStack[n].file+AAA, preyStack[n].rank+ONE);
2417 fprintf(debugFP, "always chased upto ply %d\n", i);
2419 // now adjust the location of the chased pieces according to opponent move
2420 for(j=0; j<preyStackPointer; j++) {
2421 if(preyStack[j].rank == moveList[i+1][1]-ONE &&
2422 preyStack[j].file == moveList[i+1][0]-AAA+BOARD_LEFT) {
2423 preyStack[j].rank = moveList[i+1][3]-ONE;
2424 preyStack[j].file = moveList[i+1][2]-AAA+BOARD_LEFT;
2429 return preyStackPointer ? 256*(preyStack[preyStackPointer].file - BOARD_LEFT + AAA) + (preyStack[preyStackPointer].rank + ONE)
2430 : 0; // if any piece was left on preyStack, it has been perpetually chased,and we return the