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
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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
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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];
77 char *defaultDesc[EmptySquare] = {
78 "fmWfceFifmnD", "N", "B", "R", "Q",
79 "F", "A", "BN", "RN", "W", "K",
80 "mRcpR", "N0", "BW", "RF", "gQ",
81 "", "", "QN", "", "N", "",
83 "", "", "", "", "", "",
85 "", "", "", "", "", "K"
89 WhitePiece (ChessSquare piece)
91 return (int) piece >= (int) WhitePawn && (int) piece < (int) BlackPawn;
95 BlackPiece (ChessSquare piece)
97 return (int) piece >= (int) BlackPawn && (int) piece < (int) EmptySquare;
102 SameColor (ChessSquare piece1, ChessSquare piece2)
104 return ((int) piece1 >= (int) WhitePawn && /* [HGM] can be > King ! */
105 (int) piece1 < (int) BlackPawn &&
106 (int) piece2 >= (int) WhitePawn &&
107 (int) piece2 < (int) BlackPawn)
108 || ((int) piece1 >= (int) BlackPawn &&
109 (int) piece1 < (int) EmptySquare &&
110 (int) piece2 >= (int) BlackPawn &&
111 (int) piece2 < (int) EmptySquare);
114 #define SameColor(piece1, piece2) (piece1 < EmptySquare && piece2 < EmptySquare && (piece1 < BlackPawn) == (piece2 < BlackPawn) || piece1 == DarkSquare || piece2 == DarkSquare)
117 char pieceToChar[] = {
118 'P', 'N', 'B', 'R', 'Q', 'F', 'E', 'A', 'C', 'W', 'M',
119 'O', 'H', 'I', 'J', 'G', 'D', 'V', 'L', 'S', 'U', 'K',
120 'p', 'n', 'b', 'r', 'q', 'f', 'e', 'a', 'c', 'w', 'm',
121 'o', 'h', 'i', 'j', 'g', 'd', 'v', 'l', 's', 'u', 'k',
123 char pieceNickName[EmptySquare];
126 PieceToChar (ChessSquare p)
128 if((int)p < 0 || (int)p >= (int)EmptySquare) return('x'); /* [HGM] for safety */
129 return pieceToChar[(int) p];
133 PieceToNumber (ChessSquare p) /* [HGM] holdings: count piece type, ignoring non-participating piece types */
136 ChessSquare start = (int)p >= (int)BlackPawn ? BlackPawn : WhitePawn;
138 while(start++ != p) if(pieceToChar[start-1] != '.' && pieceToChar[start-1] != '+') i++;
146 if(c == '.') return EmptySquare;
147 for(i=0; i< (int) EmptySquare; i++)
148 if(pieceNickName[i] == c) return (ChessSquare) i;
149 for(i=0; i< (int) EmptySquare; i++)
150 if(pieceToChar[i] == c) return (ChessSquare) i;
155 CopyBoard (Board to, Board from)
159 for (i = 0; i < BOARD_HEIGHT; i++)
160 for (j = 0; j < BOARD_WIDTH; j++)
161 to[i][j] = from[i][j];
162 for (j = 0; j < BOARD_FILES; j++) // [HGM] gamestate: copy castling rights and ep status
163 to[VIRGIN][j] = from[VIRGIN][j],
164 to[CASTLING][j] = from[CASTLING][j];
165 to[HOLDINGS_SET] = 0; // flag used in ICS play
169 CompareBoards (Board board1, Board board2)
173 for (i = 0; i < BOARD_HEIGHT; i++)
174 for (j = 0; j < BOARD_WIDTH; j++) {
175 if (board1[i][j] != board2[i][j])
181 char defaultName[] = "PNBRQ......................................K" // white
182 "pnbrq......................................k"; // black
183 char shogiName[] = "PNBRLS...G.++++++..........................K" // white
184 "pnbrls...g.++++++..........................k"; // black
185 char xqName[] = "PH.R.AE..K.C................................" // white
186 "ph.r.ae..k.c................................"; // black
189 CollectPieceDescriptors ()
190 { // make a line of piece descriptions for use in the PGN Piece tag:
191 // dump all engine defined pieces, and pieces with non-standard names,
192 // but suppress black pieces that are the same as their white counterpart
194 static char buf[MSG_SIZ];
195 char *m, c, d, *pieceName = defaultName;
198 if(!pieceDefs) return "";
199 if(gameInfo.variant == VariantChu) return ""; // for now don't do this for Chu Shogi
200 if(gameInfo.variant == VariantShogi) pieceName = shogiName;
201 if(gameInfo.variant == VariantXiangqi) pieceName = xqName;
202 for(p=WhitePawn; p<EmptySquare; p++) {
203 if((c = pieceToChar[p]) == '.' || c == '~') continue; // does not participate
204 m = pieceDesc[p]; d = (c == '+' ? pieceToChar[DEMOTED p] : c);
205 if(p >= BlackPawn && pieceToChar[BLACK_TO_WHITE p] == toupper(c)
206 && (c != '+' || pieceToChar[DEMOTED BLACK_TO_WHITE p] == d)) { // black member of normal pair
207 char *wm = pieceDesc[BLACK_TO_WHITE p];
208 if(!m && !wm || m && wm && !strcmp(wm, m)) continue; // moves as a white piece
209 } else // white or unpaired black
210 if((p < BlackPawn || CharToPiece(toupper(d)) != EmptySquare) && // white or lone black
211 !pieceDesc[p] /*&& pieceName[p] == c*/) continue; // orthodox piece known by its usual name
212 // TODO: listing pieces because of unusual name can only be done if we have accurate Betza of all defaults
213 if(!m) m = defaultDesc[p];
215 snprintf(buf+len, MSG_SIZ-len, "%s%s%c:%s", len ? ";" : "", c == '+' ? "+" : "", d, m);
220 // [HGM] gen: configurable move generation from Betza notation sent by engine.
221 // Some notes about two-leg moves: GenPseudoLegal() works in two modes, depending on whether a 'kill-
222 // square has been set: without one is generates all moves, and a global int legNr flags in bits 0 and 1
223 // if the move has 1 or 2 legs. Only the marking of squares makes use of this info, by only marking
224 // target squares of leg 1 (rejecting null move). A dummy move with MoveType 'FirstLeg' to the relay square
225 // is generated, so a cyan marker can be put there, and other functions can ignore such a move. When the
226 // user selects this square, it becomes the kill-square. Once a kill-square is set, only 2-leg moves are
227 // generated that use that square as relay, plus 1-leg moves, so the 1-leg move that goes to the kill-square
228 // can be marked during 2nd-leg entry to terminate the move there. For judging the pseudo-legality of the
229 // 2nd leg, the from-square has to be considered empty, although the moving piece is still on it.
233 // alphabet "abcdefghijklmnopqrstuvwxyz"
234 char symmetry[] = "FBNW.FFW.NKN.NW.QR....W..N";
235 char xStep[] = "2110.130.102.10.00....0..2";
236 char yStep[] = "2132.133.313.20.11....1..3";
237 char dirType[] = "01000104000200000260050000";
238 char upgrade[] = "AFCD.BGH.JQL.NO.KW....R..Z";
239 char rotate[] = "DRCA.WHG.JKL.NO.QB....F..Z";
241 // 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 "
242 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 };
243 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 };
244 int dirs3[] = { 0,0x38,0,0,0,0x83,0,0xFF,0,0,0,0xE0,0,0,0,0,0,0x0E,0xEE,0,0,0xBB,0,0,0,0 };
245 int dirs4[] = { 0,0x10,0,0,0,0x01,0,0xFF,0,0,0,0x40,0,0,0,0,0,0x04,0x44,0,0,0x11,0,0,0,0 };
247 int rot[][4] = { // rotation matrices for each direction
259 OK (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR cl)
265 MovesFromString (Board board, int flags, int f, int r, int tx, int ty, int angle, char *desc, MoveCallback cb, VOIDSTAR cl)
267 char buf[80], *p = desc, *atom = NULL;
268 int mine, his, dir, bit, occup, i, promoRank = -1;
269 ChessMove promo= NormalMove; ChessSquare pc = board[r][f];
270 if(flags & F_WHITE_ON_MOVE) his = 2, mine = 1; else his = 1, mine = 2;
271 if(pc == WhitePawn || pc == WhiteLance) promo = WhitePromotion, promoRank = BOARD_HEIGHT-1; else
272 if(pc == BlackPawn || pc == BlackLance) promo = BlackPromotion, promoRank = 0;
273 while(*p) { // more moves to go
274 int expo = 1, dx, dy, x, y, mode, dirSet, ds2=0, retry=0, initial=0, jump=1, skip = 0, all = 0;
276 if(*p == 'i') initial = 1, desc = ++p;
277 while(islower(*p)) p++; // skip prefixes
278 if(!isupper(*p)) return; // syntax error: no atom
279 dx = xStep[*p-'A'] - '0';// step vector of atom
280 dy = yStep[*p-'A'] - '0';
281 dirSet = 0; // build direction set based on atom symmetry
282 switch(symmetry[*p-'A']) {
283 case 'B': expo = 0; // bishop, slide
284 case 'F': all = 0xAA; // diagonal atom (degenerate 4-fold)
285 if(tx >= 0) goto king; // continuation legs specified in K/Q system!
286 while(islower(*desc) && (i = dirType[*desc-'a']) != '0') {
287 int b = dirs1[*desc-'a']; // use wide version
288 if( islower(desc[1]) &&
289 ((i | dirType[desc[1]-'a']) & 3) == 3) { // combinable (perpendicular dim)
290 b = dirs1[*desc-'a'] & dirs1[desc[1]-'a']; // intersect wide & perp wide
295 dirSet &= 0xAA; if(!dirSet) dirSet = 0xAA;
297 case 'R': expo = 0; // rook, slide
298 case 'W': all = 0x55; // orthogonal atom (non-deg 4-fold)
299 if(tx >= 0) goto king; // continuation legs specified in K/Q system!
300 while(islower(*desc) && (dirType[*desc-'a'] & ~4) != '0') dirSet |= dirs2[*desc++-'a'];
301 dirSet &= 0x55; if(!dirSet) dirSet = 0x55;
302 dirSet = (dirSet << angle | dirSet >> 8-angle) & 255; // re-orient direction system
304 case 'N': all = 0xFF; // oblique atom (degenerate 8-fold)
305 if(tx >= 0) goto king; // continuation legs specified in K/Q system!
306 if(*desc == 'h') { // chiral direction sets 'hr' and 'hl'
307 dirSet = (desc[1] == 'r' ? 0x55 : 0xAA); desc += 2;
309 while(islower(*desc) && (i = dirType[*desc-'a']) != '0') {
310 int b = dirs2[*desc-'a']; // when alone, use narrow version
311 if(desc[1] == 'h') b = dirs1[*desc-'a'], desc += 2; // dirs1 is wide version
312 else if(*desc == desc[1] || islower(desc[1]) && i < '4'
313 && ((i | dirType[desc[1]-'a']) & 3) == 3) { // combinable (perpendicular dim or same)
314 b = dirs1[*desc-'a'] & dirs2[desc[1]-'a']; // intersect wide & perp narrow
319 if(!dirSet) dirSet = 0xFF;
321 case 'Q': expo = 0; // queen, slide
322 case 'K': all = 0xFF; // non-deg (pseudo) 8-fold
324 while(islower(*desc) && (i = dirType[*desc-'a']) != '0') {
325 int b = dirs4[*desc-'a']; // when alone, use narrow version
326 if(desc[1] == *desc) desc++; // doubling forces alone
327 else if(islower(desc[1]) && i < '4'
328 && ((i | dirType[desc[1]-'a']) & 3) == 3) { // combinable (perpendicular dim or same)
329 b = dirs3[*desc-'a'] & dirs3[desc[1]-'a']; // intersect wide & perp wide
334 if(!dirSet) dirSet = (tx < 0 ? 0xFF // default is all directions, but in continuation leg
335 : all == 0xFF ? 0xEF : 0x45); // omits backward, and for 4-fold atoms also diags
336 dirSet = (dirSet << angle | dirSet >> 8-angle) & 255; // re-orient direction system
337 ds2 = dirSet & 0xAA; // extract diagonal directions
338 if(dirSet &= 0x55) // start with orthogonal moves, if present
339 retry = 1, dx = 0; // and schedule the diagonal moves for later
340 else dx = dy, dirSet = ds2; // if no orthogonal directions, do diagonal immediately
341 break; // should not have direction indicators
342 default: return; // syntax error: invalid atom
344 if(mine == 2 && tx < 0) dirSet = dirSet >> 4 | dirSet << 4 & 255; // invert black moves
345 mode = 0; // build mode mask
346 if(*desc == 'm') mode |= 4, desc++; // move to empty
347 if(*desc == 'c') mode |= his, desc++; // capture foe
348 if(*desc == 'd') mode |= mine, desc++; // destroy (capture friend)
349 if(*desc == 'e') mode |= 8, desc++; // e.p. capture last mover
350 if(*desc == 't') mode |= 16, desc++; // exclude enemies as hop platform ('test')
351 if(*desc == 'p') mode |= 32, desc++; // hop over occupied
352 if(*desc == 'g') mode |= 64, desc++; // hop and toggle range
353 if(*desc == 'o') mode |= 128, desc++; // wrap around cylinder board
354 if(*desc == 'y') mode |= 512, desc++; // toggle range on empty square
355 if(*desc == 'n') jump = 0, desc++; // non-jumping
356 while(*desc == 'j') jump++, desc++; // must jump (on B,R,Q: skip first square)
357 if(*desc == 'a') cont = ++desc; // move again after doing what preceded it
358 if(isdigit(*++p)) expo = atoi(p++); // read exponent
359 if(expo > 9) p++; // allow double-digit
360 desc = p; // this is start of next move
361 if(initial && (board[r][f] != initialPosition[r][f] ||
362 r == 0 && board[TOUCHED_W] & 1<<f ||
363 r == BOARD_HEIGHT-1 && board[TOUCHED_B] & 1<<f ) ) continue;
364 if(expo > 1 && dx == 0 && dy == 0) { // castling indicated by O + number
365 mode |= 1024; dy = 1;
368 if(!(mode & 15)) mode |= his + 4; // no mode spec, use default = mc
370 strncpy(buf, cont, 80); cont = buf; // copy next leg(s), so we can modify
371 atom = buf; while(islower(*atom)) atom++; // skip to atom
372 if(mode & 32) mode ^= 256 + 32; // in non-final legs 'p' means 'pass through'
373 if(mode & 64 + 512) {
374 mode |= 256; // and 'g' too, but converts leaper <-> slider
375 if(mode & 512) mode ^= 0x304; // and 'y' is m-like 'g'
376 *atom = upgrade[*atom-'A']; // replace atom, BRQ <-> FWK
377 atom[1] = atom[2] = '\0'; // make sure any old range is stripped off
378 if(expo == 1) atom[1] = '0'; // turn other leapers into riders
380 if(!(mode & 0x30F)) mode |= 4; // and default of this leg = m
382 if(dy == 1) skip = jump - 1, jump = 1; // on W & F atoms 'j' = skip first square
384 for(dir=0, bit=1; dir<8; dir++, bit += bit) { // loop over directions
385 int i = expo, j = skip, hop = mode, vx, vy, loop = 0;
386 if(!(bit & dirSet)) continue; // does not move in this direction
387 if(dy != 1) j = 0; //
388 vx = dx*rot[dir][0] + dy*rot[dir][1]; // rotate step vector
389 vy = dx*rot[dir][2] + dy*rot[dir][3];
390 if(tx < 0) x = f, y = r; // start square
391 else x = tx, y = ty; // from previous to-square if continuation
393 x += vx; y += vy; // step to next square
394 if(y < 0 || y >= BOARD_HEIGHT) break; // vertically off-board: always done
395 if(x < BOARD_LEFT) { if(mode & 128) x += BOARD_RGHT - BOARD_LEFT, loop++; else break; }
396 if(x >= BOARD_RGHT) { if(mode & 128) x -= BOARD_RGHT - BOARD_LEFT, loop++; else break; }
397 if(j) { j--; continue; } // skip irrespective of occupation
398 if(!jump && board[y - vy + vy/2][x - vx + vx/2] != EmptySquare) break; // blocked
399 if(jump > 1 && board[y - vy + vy/2][x - vx + vx/2] == EmptySquare) break; // no hop
400 if(x == f && y == r && !loop) occup = 4; else // start square counts as empty (if not around cylinder!)
401 if(board[y][x] < BlackPawn) occup = 0x101; else
402 if(board[y][x] < EmptySquare) occup = 0x102; else
404 if(cont) { // non-final leg
405 if(mode&16 && his&occup) occup &= 3;// suppress hopping foe in t-mode
406 if(occup & mode) { // valid intermediate square, do continuation
407 char origAtom = *atom;
408 if(!(bit & all)) *atom = rotate[*atom - 'A']; // orth-diag interconversion to make direction valid
409 if(occup & mode & 0x104) // no side effects, merge legs to one move
410 MovesFromString(board, flags, f, r, x, y, dir, cont, cb, cl);
411 if(occup & mode & 3 && (killX < 0 || killX == x && killY == y)) { // destructive first leg
413 MovesFromString(board, flags, f, r, x, y, dir, cont, &OK, &cnt); // count possible continuations
414 if(cnt) { // and if there are
415 if(killX < 0) cb(board, flags, FirstLeg, r, f, y, x, cl); // then generate their first leg
417 MovesFromString(board, flags, f, r, x, y, dir, cont, cb, cl);
421 *atom = origAtom; // undo any interconversion
423 if(occup != 4) break; // occupied squares always terminate the leg
426 if(hop & 32+64) { if(occup != 4) { if(hop & 64 && i != 1) i = 2; hop &= 31; } continue; } // hopper
427 if(mode & 8 && y == board[EP_RANK] && occup == 4 && board[EP_FILE] == x) { // to e.p. square
428 cb(board, flags, mine == 1 ? WhiteCapturesEnPassant : BlackCapturesEnPassant, r, f, y, x, cl);
430 if(mode & 1024) { // castling
431 i = 2; // kludge to elongate move indefinitely
432 if(occup == 4) continue; // skip empty squares
433 if(x == BOARD_LEFT && board[y][x] == initialPosition[y][x]) // reached initial corner piece
434 cb(board, flags, mine == 1 ? WhiteQueenSideCastle : BlackQueenSideCastle, r, f, y, f - expo, cl);
435 if(x == BOARD_RGHT-1 && board[y][x] == initialPosition[y][x])
436 cb(board, flags, mine == 1 ? WhiteKingSideCastle : BlackKingSideCastle, r, f, y, f + expo, cl);
439 if(mode & 16 && (board[y][x] == WhiteKing || board[y][x] == BlackKing)) break; // tame piece, cannot capture royal
440 if(occup & mode) cb(board, flags, y == promoRank ? promo : NormalMove, r, f, y, x, cl); // allowed, generate
441 if(occup != 4) break; // not valid transit square
444 dx = dy; dirSet = ds2; // prepare for diagonal moves of K,Q
445 } while(retry-- && ds2); // and start doing them
446 if(tx >= 0) break; // don't do other atoms in continuation legs
450 // [HGM] move generation now based on hierarchy of subroutines for rays and combinations of rays
453 SlideForward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
458 if (rt >= BOARD_HEIGHT) break;
459 if (SameColor(board[rf][ff], board[rt][ft])) break;
460 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
461 if (board[rt][ft] != EmptySquare) break;
466 SlideBackward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
472 if (SameColor(board[rf][ff], board[rt][ft])) break;
473 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
474 if (board[rt][ft] != EmptySquare) break;
479 SlideVertical (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
481 SlideForward(board, flags, rf, ff, callback, closure);
482 SlideBackward(board, flags, rf, ff, callback, closure);
486 SlideSideways (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
488 int i, s, rt = rf, ft;
489 for(s = -1; s <= 1; s+= 2) {
492 if (ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
493 if (SameColor(board[rf][ff], board[rt][ft])) break;
494 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
495 if (board[rt][ft] != EmptySquare) break;
501 SlideDiagForward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
504 for(s = -1; s <= 1; s+= 2) {
508 if (rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
509 if (SameColor(board[rf][ff], board[rt][ft])) break;
510 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
511 if (board[rt][ft] != EmptySquare) break;
517 SlideDiagBackward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
520 for(s = -1; s <= 1; s+= 2) {
524 if (rt < 0 || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
525 if (SameColor(board[rf][ff], board[rt][ft])) break;
526 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
527 if (board[rt][ft] != EmptySquare) break;
533 Rook (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
535 SlideVertical(board, flags, rf, ff, callback, closure);
536 SlideSideways(board, flags, rf, ff, callback, closure);
540 Bishop (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
542 SlideDiagForward(board, flags, rf, ff, callback, closure);
543 SlideDiagBackward(board, flags, rf, ff, callback, closure);
547 Sting (Board board, int flags, int rf, int ff, int dy, int dx, MoveCallback callback, VOIDSTAR closure)
548 { // Lion-like move of Horned Falcon and Souring Eagle
549 int ft = ff + dx, rt = rf + dy;
550 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) return;
552 if (!SameColor(board[rf][ff], board[rt][ft]))
553 callback(board, flags, board[rt][ft] != EmptySquare ? FirstLeg : NormalMove, rf, ff, rt, ft, closure);
556 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) return;
558 if (!SameColor(board[rf][ff], board[rt][ft]))
559 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
560 if (!SameColor(board[rf][ff], board[rf+dy][ff+dx]))
561 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
566 StepForward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
568 int ft = ff, rt = rf + 1;
569 if (rt >= BOARD_HEIGHT) return;
570 if (SameColor(board[rf][ff], board[rt][ft])) return;
571 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
575 StepBackward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
577 int ft = ff, rt = rf - 1;
579 if (SameColor(board[rf][ff], board[rt][ft])) return;
580 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
584 StepSideways (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
588 if (!(rt >= BOARD_HEIGHT || ft >= BOARD_RGHT) && !SameColor(board[rf][ff], board[rt][ft]))
589 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
591 if (!(rt >= BOARD_HEIGHT || ft < BOARD_LEFT) && !SameColor(board[rf][ff], board[rt][ft]))
592 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
596 StepDiagForward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
599 if (rt >= BOARD_HEIGHT) return;
601 if (!(rt >= BOARD_HEIGHT || ft >= BOARD_RGHT) && !SameColor(board[rf][ff], board[rt][ft]))
602 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
604 if (!(rt >= BOARD_HEIGHT || ft < BOARD_LEFT) && !SameColor(board[rf][ff], board[rt][ft]))
605 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
609 StepDiagBackward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
614 if (!(rt < 0 || ft >= BOARD_RGHT) && !SameColor(board[rf][ff], board[rt][ft]))
615 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
617 if (!(rt < 0 || ft < BOARD_LEFT) && !SameColor(board[rf][ff], board[rt][ft]))
618 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
622 StepVertical (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
624 StepForward(board, flags, rf, ff, callback, closure);
625 StepBackward(board, flags, rf, ff, callback, closure);
629 Ferz (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
631 StepDiagForward(board, flags, rf, ff, callback, closure);
632 StepDiagBackward(board, flags, rf, ff, callback, closure);
636 Wazir (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
638 StepVertical(board, flags, rf, ff, callback, closure);
639 StepSideways(board, flags, rf, ff, callback, closure);
643 Knight (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
646 for (i = -1; i <= 1; i += 2)
647 for (j = -1; j <= 1; j += 2)
648 for (s = 1; s <= 2; s++) {
651 if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
652 && ( gameInfo.variant != VariantXiangqi || board[rf+i*(s-1)][ff+j*(2-s)] == EmptySquare)
653 && !SameColor(board[rf][ff], board[rt][ft]))
654 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
658 /* Call callback once for each pseudo-legal move in the given
659 position, except castling moves. A move is pseudo-legal if it is
660 legal, or if it would be legal except that it leaves the king in
661 check. In the arguments, epfile is EP_NONE if the previous move
662 was not a double pawn push, or the file 0..7 if it was, or
663 EP_UNKNOWN if we don't know and want to allow all e.p. captures.
664 Promotion moves generated are to Queen only.
667 GenPseudoLegal (Board board, int flags, MoveCallback callback, VOIDSTAR closure, ChessSquare filter)
668 // speed: only do moves with this piece type
671 int i, j, d, s, fs, rs, rt, ft, m;
672 int epfile = (signed char)board[EP_STATUS]; // [HGM] gamestate: extract ep status from board
673 int promoRank = gameInfo.variant == VariantMakruk || gameInfo.variant == VariantGrand || gameInfo.variant == VariantChuChess ? 3 : 1;
675 for (rf = 0; rf < BOARD_HEIGHT; rf++)
676 for (ff = BOARD_LEFT; ff < BOARD_RGHT; ff++) {
679 if(board[rf][ff] == EmptySquare) continue;
680 if ((flags & F_WHITE_ON_MOVE) != (board[rf][ff] < BlackPawn)) continue; // [HGM] speed: wrong color
681 m = 0; piece = board[rf][ff];
682 if(PieceToChar(piece) == '~')
683 piece = (ChessSquare) ( DEMOTED piece );
684 if(filter != EmptySquare && piece != filter) continue;
685 if(pieceDefs && pieceDesc[piece]) { // [HGM] gen: use engine-defined moves
686 MovesFromString(board, flags, ff, rf, -1, -1, 0, pieceDesc[piece], callback, closure);
689 if(IS_SHOGI(gameInfo.variant))
690 piece = (ChessSquare) ( SHOGI piece );
692 switch ((int)piece) {
693 /* case EmptySquare: [HGM] this is nonsense, and conflicts with Shogi cases */
695 /* can't happen ([HGM] except for faries...) */
699 if(gameInfo.variant == VariantXiangqi) {
700 /* [HGM] capture and move straight ahead in Xiangqi */
701 if (rf < BOARD_HEIGHT-1 &&
702 !SameColor(board[rf][ff], board[rf + 1][ff]) ) {
703 callback(board, flags, NormalMove,
704 rf, ff, rf + 1, ff, closure);
706 /* and move sideways when across the river */
707 for (s = -1; s <= 1; s += 2) {
708 if (rf >= BOARD_HEIGHT>>1 &&
709 ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
710 !WhitePiece(board[rf][ff+s]) ) {
711 callback(board, flags, NormalMove,
712 rf, ff, rf, ff+s, closure);
717 if (rf < BOARD_HEIGHT-1 && board[rf + 1][ff] == EmptySquare) {
718 callback(board, flags,
719 rf >= BOARD_HEIGHT-1-promoRank ? WhitePromotion : NormalMove,
720 rf, ff, rf + 1, ff, closure);
722 if (rf <= (BOARD_HEIGHT>>1)-3 && board[rf+1][ff] == EmptySquare && // [HGM] grand: also on 3rd rank on 10-board
723 gameInfo.variant != VariantShatranj && /* [HGM] */
724 gameInfo.variant != VariantCourier && /* [HGM] */
725 board[rf+2][ff] == EmptySquare ) {
726 callback(board, flags, NormalMove,
727 rf, ff, rf+2, ff, closure);
729 for (s = -1; s <= 1; s += 2) {
730 if (rf < BOARD_HEIGHT-1 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
731 ((flags & F_KRIEGSPIEL_CAPTURE) ||
732 BlackPiece(board[rf + 1][ff + s]))) {
733 callback(board, flags,
734 rf >= BOARD_HEIGHT-1-promoRank ? WhitePromotion : NormalMove,
735 rf, ff, rf + 1, ff + s, closure);
737 if (rf >= BOARD_HEIGHT+1>>1) {// [HGM] grand: 4th & 5th rank on 10-board
738 if (ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
739 (epfile == ff + s || epfile == EP_UNKNOWN) && rf < BOARD_HEIGHT-3 &&
740 board[rf][ff + s] == BlackPawn &&
741 board[rf+1][ff + s] == EmptySquare) {
742 callback(board, flags, WhiteCapturesEnPassant,
743 rf, ff, rf+1, ff + s, closure);
750 if(gameInfo.variant == VariantXiangqi) {
751 /* [HGM] capture straight ahead in Xiangqi */
752 if (rf > 0 && !SameColor(board[rf][ff], board[rf - 1][ff]) ) {
753 callback(board, flags, NormalMove,
754 rf, ff, rf - 1, ff, closure);
756 /* and move sideways when across the river */
757 for (s = -1; s <= 1; s += 2) {
758 if (rf < BOARD_HEIGHT>>1 &&
759 ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
760 !BlackPiece(board[rf][ff+s]) ) {
761 callback(board, flags, NormalMove,
762 rf, ff, rf, ff+s, closure);
767 if (rf > 0 && board[rf - 1][ff] == EmptySquare) {
768 callback(board, flags,
769 rf <= promoRank ? BlackPromotion : NormalMove,
770 rf, ff, rf - 1, ff, closure);
772 if (rf >= (BOARD_HEIGHT+1>>1)+2 && board[rf-1][ff] == EmptySquare && // [HGM] grand
773 gameInfo.variant != VariantShatranj && /* [HGM] */
774 gameInfo.variant != VariantCourier && /* [HGM] */
775 board[rf-2][ff] == EmptySquare) {
776 callback(board, flags, NormalMove,
777 rf, ff, rf-2, ff, closure);
779 for (s = -1; s <= 1; s += 2) {
780 if (rf > 0 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
781 ((flags & F_KRIEGSPIEL_CAPTURE) ||
782 WhitePiece(board[rf - 1][ff + s]))) {
783 callback(board, flags,
784 rf <= promoRank ? BlackPromotion : NormalMove,
785 rf, ff, rf - 1, ff + s, closure);
787 if (rf < BOARD_HEIGHT>>1) {
788 if (ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
789 (epfile == ff + s || epfile == EP_UNKNOWN) && rf > 2 &&
790 board[rf][ff + s] == WhitePawn &&
791 board[rf-1][ff + s] == EmptySquare) {
792 callback(board, flags, BlackCapturesEnPassant,
793 rf, ff, rf-1, ff + s, closure);
803 for (i = -1; i <= 1; i += 2)
804 for (j = -1; j <= 1; j += 2)
805 for (s = 1; s <= 2; s++) {
808 if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
809 && ( gameInfo.variant != VariantXiangqi || board[rf+i*(s-1)][ff+j*(2-s)] == EmptySquare)
810 && !SameColor(board[rf][ff], board[rt][ft]))
811 callback(board, flags, NormalMove,
812 rf, ff, rt, ft, closure);
816 case SHOGI WhiteKnight:
817 for (s = -1; s <= 1; s += 2) {
818 if (rf < BOARD_HEIGHT-2 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
819 !SameColor(board[rf][ff], board[rf + 2][ff + s])) {
820 callback(board, flags, NormalMove,
821 rf, ff, rf + 2, ff + s, closure);
826 case SHOGI BlackKnight:
827 for (s = -1; s <= 1; s += 2) {
828 if (rf > 1 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
829 !SameColor(board[rf][ff], board[rf - 2][ff + s])) {
830 callback(board, flags, NormalMove,
831 rf, ff, rf - 2, ff + s, closure);
838 for (d = 0; d <= 1; d++)
839 for (s = -1; s <= 1; s += 2) {
842 rt = rf + (i * s) * d;
843 ft = ff + (i * s) * (1 - d);
844 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
845 if (m == 0 && board[rt][ft] == EmptySquare)
846 callback(board, flags, NormalMove,
847 rf, ff, rt, ft, closure);
848 if (m == 1 && board[rt][ft] != EmptySquare &&
849 !SameColor(board[rf][ff], board[rt][ft]) )
850 callback(board, flags, NormalMove,
851 rf, ff, rt, ft, closure);
852 if (board[rt][ft] != EmptySquare && m++) break;
857 /* Gold General (and all its promoted versions) . First do the */
858 /* diagonal forward steps, then proceed as normal Wazir */
859 case SHOGI (PROMOTED WhitePawn):
860 if(gameInfo.variant == VariantShogi) goto WhiteGold;
861 case SHOGI (PROMOTED BlackPawn):
862 if(gameInfo.variant == VariantShogi) goto BlackGold;
863 SlideVertical(board, flags, rf, ff, callback, closure);
866 case SHOGI (PROMOTED WhiteKnight):
867 if(gameInfo.variant == VariantShogi) goto WhiteGold;
868 case SHOGI BlackDrunk:
869 case SHOGI BlackAlfil:
870 Ferz(board, flags, rf, ff, callback, closure);
871 StepSideways(board, flags, rf, ff, callback, closure);
872 StepBackward(board, flags, rf, ff, callback, closure);
875 case SHOGI (PROMOTED BlackKnight):
876 if(gameInfo.variant == VariantShogi) goto BlackGold;
877 case SHOGI WhiteDrunk:
878 case SHOGI WhiteAlfil:
879 Ferz(board, flags, rf, ff, callback, closure);
880 StepSideways(board, flags, rf, ff, callback, closure);
881 StepForward(board, flags, rf, ff, callback, closure);
885 case SHOGI WhiteStag:
886 case SHOGI BlackStag:
887 if(gameInfo.variant == VariantShogi) goto BlackGold;
888 SlideVertical(board, flags, rf, ff, callback, closure);
889 Ferz(board, flags, rf, ff, callback, closure);
890 StepSideways(board, flags, rf, ff, callback, closure);
893 case SHOGI (PROMOTED WhiteQueen):
894 case SHOGI WhiteTokin:
895 case SHOGI WhiteWazir:
897 StepDiagForward(board, flags, rf, ff, callback, closure);
898 Wazir(board, flags, rf, ff, callback, closure);
901 case SHOGI (PROMOTED BlackQueen):
902 case SHOGI BlackTokin:
903 case SHOGI BlackWazir:
905 StepDiagBackward(board, flags, rf, ff, callback, closure);
906 Wazir(board, flags, rf, ff, callback, closure);
911 Wazir(board, flags, rf, ff, callback, closure);
914 case SHOGI WhiteMarshall:
915 case SHOGI BlackMarshall:
916 Ferz(board, flags, rf, ff, callback, closure);
917 for (d = 0; d <= 1; d++)
918 for (s = -2; s <= 2; s += 4) {
920 ft = ff + s * (1 - d);
921 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) continue;
922 if (!SameColor(board[rf][ff], board[rt][ft]) )
923 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
927 case SHOGI WhiteAngel:
928 case SHOGI BlackAngel:
929 Wazir(board, flags, rf, ff, callback, closure);
933 /* [HGM] support Shatranj pieces */
934 for (rs = -1; rs <= 1; rs += 2)
935 for (fs = -1; fs <= 1; fs += 2) {
938 if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
939 && ( gameInfo.variant != VariantXiangqi ||
940 board[rf+rs][ff+fs] == EmptySquare && (2*rf < BOARD_HEIGHT) == (2*rt < BOARD_HEIGHT) )
942 && !SameColor(board[rf][ff], board[rt][ft]))
943 callback(board, flags, NormalMove,
944 rf, ff, rt, ft, closure);
945 if(gameInfo.variant == VariantShatranj || gameInfo.variant == VariantCourier ||
946 gameInfo.variant == VariantChu || gameInfo.variant == VariantXiangqi) continue; // classical Alfil
947 rt = rf + rs; // in unknown variant we assume Modern Elephant, which can also do one step
949 if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
950 && !SameColor(board[rf][ff], board[rt][ft]))
951 callback(board, flags, NormalMove,
952 rf, ff, rt, ft, closure);
954 if(gameInfo.variant == VariantSpartan)
955 for(fs = -1; fs <= 1; fs += 2) {
957 if (!(ft < BOARD_LEFT || ft >= BOARD_RGHT) && board[rf][ft] == EmptySquare)
958 callback(board, flags, NormalMove, rf, ff, rf, ft, closure);
962 /* Make Dragon-Horse also do Dababba moves outside Shogi, for better disambiguation in variant Fairy */
965 if(gameInfo.variant == VariantChuChess) goto DragonHorse;
966 for (d = 0; d <= 1; d++) // Dababba moves that Rook cannot do
967 for (s = -2; s <= 2; s += 4) {
969 ft = ff + s * (1 - d);
970 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) continue;
971 if (SameColor(board[rf][ff], board[rt][ft])) continue;
972 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
975 /* Shogi Dragon Horse has to continue with Wazir after Bishop */
976 case SHOGI WhiteCardinal:
977 case SHOGI BlackCardinal:
978 case SHOGI WhitePCardinal:
979 case SHOGI BlackPCardinal:
981 Bishop(board, flags, rf, ff, callback, closure);
982 Wazir(board, flags, rf, ff, callback, closure);
985 /* Capablanca Archbishop continues as Knight */
988 Knight(board, flags, rf, ff, callback, closure);
990 /* Shogi Bishops are ordinary Bishops */
991 case SHOGI WhiteBishop:
992 case SHOGI BlackBishop:
993 case SHOGI WhitePBishop:
994 case SHOGI BlackPBishop:
997 Bishop(board, flags, rf, ff, callback, closure);
1000 /* Shogi Lance is unlike anything, and asymmetric at that */
1001 case SHOGI WhiteQueen:
1002 if(gameInfo.variant == VariantChu) goto doQueen;
1006 if (rt >= BOARD_HEIGHT) break;
1007 if (SameColor(board[rf][ff], board[rt][ft])) break;
1008 callback(board, flags, NormalMove,
1009 rf, ff, rt, ft, closure);
1010 if (board[rt][ft] != EmptySquare) break;
1014 case SHOGI BlackQueen:
1015 if(gameInfo.variant == VariantChu) goto doQueen;
1020 if (SameColor(board[rf][ff], board[rt][ft])) break;
1021 callback(board, flags, NormalMove,
1022 rf, ff, rt, ft, closure);
1023 if (board[rt][ft] != EmptySquare) break;
1027 /* Make Dragon-King Dababba & Rook-like outside Shogi, for better disambiguation in variant Fairy */
1030 if(gameInfo.variant == VariantChuChess) goto DragonKing;
1031 for (d = 0; d <= 1; d++) // Dababba moves that Rook cannot do
1032 for (s = -2; s <= 2; s += 4) {
1034 ft = ff + s * (1 - d);
1035 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) continue;
1036 if (board[rf+rt>>1][ff+ft>>1] == EmptySquare && gameInfo.variant != VariantSpartan) continue;
1037 if (SameColor(board[rf][ff], board[rt][ft])) continue;
1038 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
1040 if(gameInfo.variant == VariantSpartan) // in Spartan Chess restrict range to modern Dababba
1041 Wazir(board, flags, rf, ff, callback, closure);
1043 Rook(board, flags, rf, ff, callback, closure);
1046 /* Shogi Dragon King has to continue as Ferz after Rook moves */
1047 case SHOGI WhiteDragon:
1048 case SHOGI BlackDragon:
1049 case SHOGI WhitePDragon:
1050 case SHOGI BlackPDragon:
1052 Rook(board, flags, rf, ff, callback, closure);
1053 Ferz(board, flags, rf, ff, callback, closure);
1057 /* Capablanca Chancellor sets flag to continue as Knight */
1060 Rook(board, flags, rf, ff, callback, closure);
1061 if(gameInfo.variant == VariantSpartan) // in Spartan Chess Chancellor is used for Dragon King.
1062 Ferz(board, flags, rf, ff, callback, closure);
1064 Knight(board, flags, rf, ff, callback, closure);
1067 /* Shogi Rooks are ordinary Rooks */
1068 case SHOGI WhiteRook:
1069 case SHOGI BlackRook:
1070 case SHOGI WhitePRook:
1071 case SHOGI BlackPRook:
1074 Rook(board, flags, rf, ff, callback, closure);
1079 case SHOGI WhiteMother:
1080 case SHOGI BlackMother:
1082 Rook(board, flags, rf, ff, callback, closure);
1083 Bishop(board, flags, rf, ff, callback, closure);
1086 case SHOGI WhitePawn:
1087 StepForward(board, flags, rf, ff, callback, closure);
1090 case SHOGI BlackPawn:
1091 StepBackward(board, flags, rf, ff, callback, closure);
1095 if(gameInfo.variant != VariantMakruk && gameInfo.variant != VariantASEAN) goto commoner;
1096 case SHOGI WhiteFerz:
1097 Ferz(board, flags, rf, ff, callback, closure);
1098 StepForward(board, flags, rf, ff, callback, closure);
1102 if(gameInfo.variant != VariantMakruk && gameInfo.variant != VariantASEAN) goto commoner;
1103 case SHOGI BlackFerz:
1104 StepBackward(board, flags, rf, ff, callback, closure);
1108 /* [HGM] support Shatranj pieces */
1109 Ferz(board, flags, rf, ff, callback, closure);
1114 Knight(board, flags, rf, ff, callback, closure); // [HGM] superchess: use for Centaur
1117 case SHOGI WhiteMonarch:
1118 case SHOGI BlackMonarch:
1119 case SHOGI WhiteKing:
1120 case SHOGI BlackKing:
1123 Ferz(board, flags, rf, ff, callback, closure);
1124 Wazir(board, flags, rf, ff, callback, closure);
1127 case WhiteNightrider:
1128 case BlackNightrider:
1129 for (i = -1; i <= 1; i += 2)
1130 for (j = -1; j <= 1; j += 2)
1131 for (s = 1; s <= 2; s++) { int k;
1134 ft = ff + k*j*(3-s);
1135 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
1136 if (SameColor(board[rf][ff], board[rt][ft])) break;
1137 callback(board, flags, NormalMove,
1138 rf, ff, rt, ft, closure);
1139 if (board[rt][ft] != EmptySquare) break;
1145 Bishop(board, flags, rf, ff, callback, closure);
1146 Rook(board, flags, rf, ff, callback, closure);
1147 Knight(board, flags, rf, ff, callback, closure);
1150 // Use Lance as Berolina / Spartan Pawn.
1152 if(gameInfo.variant == VariantSuper) goto Amazon;
1153 if (rf < BOARD_HEIGHT-1 && BlackPiece(board[rf + 1][ff]))
1154 callback(board, flags,
1155 rf >= BOARD_HEIGHT-1-promoRank ? WhitePromotion : NormalMove,
1156 rf, ff, rf + 1, ff, closure);
1157 for (s = -1; s <= 1; s += 2) {
1158 if (rf < BOARD_HEIGHT-1 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT && board[rf + 1][ff + s] == EmptySquare)
1159 callback(board, flags,
1160 rf >= BOARD_HEIGHT-1-promoRank ? WhitePromotion : NormalMove,
1161 rf, ff, rf + 1, ff + s, closure);
1162 if (rf == 1 && ff + 2*s >= BOARD_LEFT && ff + 2*s < BOARD_RGHT && board[3][ff + 2*s] == EmptySquare )
1163 callback(board, flags, NormalMove, rf, ff, 3, ff + 2*s, closure);
1168 if(gameInfo.variant == VariantSuper) goto Amazon;
1169 if (rf > 0 && WhitePiece(board[rf - 1][ff]))
1170 callback(board, flags,
1171 rf <= promoRank ? BlackPromotion : NormalMove,
1172 rf, ff, rf - 1, ff, closure);
1173 for (s = -1; s <= 1; s += 2) {
1174 if (rf > 0 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT && board[rf - 1][ff + s] == EmptySquare)
1175 callback(board, flags,
1176 rf <= promoRank ? BlackPromotion : NormalMove,
1177 rf, ff, rf - 1, ff + s, closure);
1178 if (rf == BOARD_HEIGHT-2 && ff + 2*s >= BOARD_LEFT && ff + 2*s < BOARD_RGHT && board[rf-2][ff + 2*s] == EmptySquare )
1179 callback(board, flags, NormalMove, rf, ff, rf-2, ff + 2*s, closure);
1183 case SHOGI WhiteNothing:
1184 case SHOGI BlackNothing:
1185 case SHOGI WhiteLion:
1186 case SHOGI BlackLion:
1189 for(rt = rf - 2; rt <= rf + 2; rt++) for(ft = ff - 2; ft <= ff + 2; ft++) {
1190 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) continue;
1191 if (!(ff == ft && rf == rt) && SameColor(board[rf][ff], board[rt][ft])) continue;
1192 i = (killX >= 0 && (rt-killY)*(rt-killY) + (killX-ft)*(killX-ft) < 3); legNr += 2*i;
1193 callback(board, flags, (rt-rf)*(rt-rf) + (ff-ft)*(ff-ft) < 3 && board[rt][ft] != EmptySquare ? FirstLeg : NormalMove,
1194 rf, ff, rt, ft, closure);
1199 case SHOGI WhiteFalcon:
1200 case SHOGI BlackFalcon:
1201 case SHOGI WhitePDagger:
1202 case SHOGI BlackPDagger:
1203 SlideSideways(board, flags, rf, ff, callback, closure);
1204 StepVertical(board, flags, rf, ff, callback, closure);
1207 case SHOGI WhiteCobra:
1208 case SHOGI BlackCobra:
1209 StepVertical(board, flags, rf, ff, callback, closure);
1212 case SHOGI (PROMOTED WhiteFerz):
1213 if(gameInfo.variant == VariantShogi) goto WhiteGold;
1214 case SHOGI (PROMOTED BlackFerz):
1215 if(gameInfo.variant == VariantShogi) goto BlackGold;
1216 case SHOGI WhitePSword:
1217 case SHOGI BlackPSword:
1218 SlideVertical(board, flags, rf, ff, callback, closure);
1219 StepSideways(board, flags, rf, ff, callback, closure);
1222 case SHOGI WhiteUnicorn:
1223 case SHOGI BlackUnicorn:
1224 Ferz(board, flags, rf, ff, callback, closure);
1225 StepVertical(board, flags, rf, ff, callback, closure);
1228 case SHOGI WhiteMan:
1229 StepDiagForward(board, flags, rf, ff, callback, closure);
1230 StepVertical(board, flags, rf, ff, callback, closure);
1233 case SHOGI BlackMan:
1234 StepDiagBackward(board, flags, rf, ff, callback, closure);
1235 StepVertical(board, flags, rf, ff, callback, closure);
1238 case SHOGI WhiteHCrown:
1239 case SHOGI BlackHCrown:
1240 Bishop(board, flags, rf, ff, callback, closure);
1241 SlideSideways(board, flags, rf, ff, callback, closure);
1244 case SHOGI WhiteCrown:
1245 case SHOGI BlackCrown:
1246 Bishop(board, flags, rf, ff, callback, closure);
1247 SlideVertical(board, flags, rf, ff, callback, closure);
1250 case SHOGI WhiteHorned:
1251 Sting(board, flags, rf, ff, 1, 0, callback, closure);
1252 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1253 if(killX >= 0) break;
1254 Bishop(board, flags, rf, ff, callback, closure);
1255 SlideSideways(board, flags, rf, ff, callback, closure);
1256 SlideBackward(board, flags, rf, ff, callback, closure);
1259 case SHOGI BlackHorned:
1260 Sting(board, flags, rf, ff, -1, 0, callback, closure);
1261 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1262 if(killX >= 0) break;
1263 Bishop(board, flags, rf, ff, callback, closure);
1264 SlideSideways(board, flags, rf, ff, callback, closure);
1265 SlideForward(board, flags, rf, ff, callback, closure);
1268 case SHOGI WhiteEagle:
1269 Sting(board, flags, rf, ff, 1, 1, callback, closure);
1270 Sting(board, flags, rf, ff, 1, -1, callback, closure);
1271 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1272 if(killX >= 0) break;
1273 Rook(board, flags, rf, ff, callback, closure);
1274 SlideDiagBackward(board, flags, rf, ff, callback, closure);
1277 case SHOGI BlackEagle:
1278 Sting(board, flags, rf, ff, -1, 1, callback, closure);
1279 Sting(board, flags, rf, ff, -1, -1, callback, closure);
1280 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1281 if(killX >= 0) break;
1282 Rook(board, flags, rf, ff, callback, closure);
1283 SlideDiagForward(board, flags, rf, ff, callback, closure);
1286 case SHOGI WhiteDolphin:
1287 case SHOGI BlackHorse:
1288 SlideDiagBackward(board, flags, rf, ff, callback, closure);
1289 SlideVertical(board, flags, rf, ff, callback, closure);
1292 case SHOGI BlackDolphin:
1293 case SHOGI WhiteHorse:
1294 SlideDiagForward(board, flags, rf, ff, callback, closure);
1295 SlideVertical(board, flags, rf, ff, callback, closure);
1298 case SHOGI WhiteLance:
1299 SlideForward(board, flags, rf, ff, callback, closure);
1302 case SHOGI BlackLance:
1303 SlideBackward(board, flags, rf, ff, callback, closure);
1306 case WhiteFalcon: // [HGM] wild: for wildcards, self-capture symbolizes move to anywhere
1310 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1323 int rFilter, fFilter; // [HGM] speed: sorry, but I get a bit tired of this closure madness
1324 Board xqCheckers, nullBoard;
1326 extern void GenLegalCallback P((Board board, int flags, ChessMove kind,
1327 int rf, int ff, int rt, int ft,
1331 GenLegalCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1333 register GenLegalClosure *cl = (GenLegalClosure *) closure;
1335 if(rFilter >= 0 && rFilter != rt || fFilter >= 0 && fFilter != ft) return; // [HGM] speed: ignore moves with wrong to-square
1337 if (board[EP_STATUS] == EP_IRON_LION && (board[rt][ft] == WhiteLion || board[rt][ft] == BlackLion)) return; //[HGM] lion
1339 if (!(flags & F_IGNORE_CHECK) ) {
1340 int check, promo = (gameInfo.variant == VariantSpartan && kind == BlackPromotion);
1343 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++)
1344 kings += (board[r][f] == BlackKing);
1348 board[rf][ff] = BlackKing; // [HGM] spartan: promote to King before check-test
1350 check = CheckTest(board, flags, rf, ff, rt, ft,
1351 kind == WhiteCapturesEnPassant ||
1352 kind == BlackCapturesEnPassant);
1353 if(promo) board[rf][ff] = BlackLance;
1356 if (flags & F_ATOMIC_CAPTURE) {
1357 if (board[rt][ft] != EmptySquare ||
1358 kind == WhiteCapturesEnPassant || kind == BlackCapturesEnPassant) {
1360 ChessSquare king = (flags & F_WHITE_ON_MOVE) ? WhiteKing : BlackKing;
1361 if (board[rf][ff] == king) return;
1362 for (r = rt-1; r <= rt+1; r++) {
1363 for (f = ft-1; f <= ft+1; f++) {
1364 if (r >= 0 && r < BOARD_HEIGHT && f >= BOARD_LEFT && f < BOARD_RGHT &&
1365 board[r][f] == king) return;
1370 cl->cb(board, flags, kind, rf, ff, rt, ft, cl->cl);
1377 int captures; // [HGM] losers
1378 } LegalityTestClosure;
1381 /* Like GenPseudoLegal, but (1) include castling moves, (2) unless
1382 F_IGNORE_CHECK is set in the flags, omit moves that would leave the
1383 king in check, and (3) if F_ATOMIC_CAPTURE is set in the flags, omit
1384 moves that would destroy your own king. The CASTLE_OK flags are
1385 true if castling is not yet ruled out by a move of the king or
1386 rook. Return TRUE if the player on move is currently in check and
1387 F_IGNORE_CHECK is not set. [HGM] add castlingRights parameter */
1389 GenLegal (Board board, int flags, MoveCallback callback, VOIDSTAR closure, ChessSquare filter)
1392 int ff, ft, k, left, right, swap;
1393 int ignoreCheck = (flags & F_IGNORE_CHECK) != 0;
1394 ChessSquare wKing = WhiteKing, bKing = BlackKing, *castlingRights = board[CASTLING];
1395 int inCheck = !ignoreCheck && CheckTest(board, flags, -1, -1, -1, -1, FALSE); // kludge alert: this would mark pre-existing checkers if status==1
1400 xqCheckers[EP_STATUS] *= 2; // quasi: if previous CheckTest has been marking, we now set flag for suspending same checkers
1401 if(filter == EmptySquare) rFilter = fFilter = -1; // [HGM] speed: do not filter on square if we do not filter on piece
1402 GenPseudoLegal(board, flags, GenLegalCallback, (VOIDSTAR) &cl, filter);
1404 if (inCheck) return TRUE;
1406 /* Generate castling moves */
1407 if(gameInfo.variant == VariantKnightmate) { /* [HGM] Knightmate */
1408 wKing = WhiteUnicorn; bKing = BlackUnicorn;
1411 p = (flags & F_WHITE_ON_MOVE ? pieceDesc[wKing] : pieceDesc[bKing]);
1412 if(p && strchr(p, 'O')) return FALSE; // [HGM] gen: castlings were already generated from string
1414 for (ff = BOARD_WIDTH>>1; ff >= (BOARD_WIDTH-1)>>1; ff-- /*ics wild 1*/) {
1415 if ((flags & F_WHITE_ON_MOVE) &&
1416 (flags & F_WHITE_KCASTLE_OK) &&
1417 board[0][ff] == wKing &&
1418 board[0][ff + 1] == EmptySquare &&
1419 board[0][ff + 2] == EmptySquare &&
1420 board[0][BOARD_RGHT-3] == EmptySquare &&
1421 board[0][BOARD_RGHT-2] == EmptySquare &&
1422 board[0][BOARD_RGHT-1] == WhiteRook &&
1423 castlingRights[0] != NoRights && /* [HGM] check rights */
1424 ( castlingRights[2] == ff || castlingRights[6] == ff ) &&
1426 (!CheckTest(board, flags, 0, ff, 0, ff + 1, FALSE) &&
1427 !CheckTest(board, flags, 0, ff, 0, BOARD_RGHT-3, FALSE) &&
1428 (gameInfo.variant != VariantJanus || !CheckTest(board, flags, 0, ff, 0, BOARD_RGHT-2, FALSE)) &&
1429 !CheckTest(board, flags, 0, ff, 0, ff + 2, FALSE)))) {
1431 callback(board, flags,
1432 ff==BOARD_WIDTH>>1 ? WhiteKingSideCastle : WhiteKingSideCastleWild,
1433 0, ff, 0, ff + ((gameInfo.boardWidth+2)>>2) + (gameInfo.variant == VariantJanus), closure);
1435 if ((flags & F_WHITE_ON_MOVE) &&
1436 (flags & F_WHITE_QCASTLE_OK) &&
1437 board[0][ff] == wKing &&
1438 board[0][ff - 1] == EmptySquare &&
1439 board[0][ff - 2] == EmptySquare &&
1440 board[0][BOARD_LEFT+2] == EmptySquare &&
1441 board[0][BOARD_LEFT+1] == EmptySquare &&
1442 board[0][BOARD_LEFT+0] == WhiteRook &&
1443 castlingRights[1] != NoRights && /* [HGM] check rights */
1444 ( castlingRights[2] == ff || castlingRights[6] == ff ) &&
1446 (!CheckTest(board, flags, 0, ff, 0, ff - 1, FALSE) &&
1447 !CheckTest(board, flags, 0, ff, 0, BOARD_LEFT+3, FALSE) &&
1448 !CheckTest(board, flags, 0, ff, 0, ff - 2, FALSE)))) {
1450 callback(board, flags,
1451 ff==BOARD_WIDTH>>1 ? WhiteQueenSideCastle : WhiteQueenSideCastleWild,
1452 0, ff, 0, ff - ((gameInfo.boardWidth+2)>>2), closure);
1454 if (!(flags & F_WHITE_ON_MOVE) &&
1455 (flags & F_BLACK_KCASTLE_OK) &&
1456 board[BOARD_HEIGHT-1][ff] == bKing &&
1457 board[BOARD_HEIGHT-1][ff + 1] == EmptySquare &&
1458 board[BOARD_HEIGHT-1][ff + 2] == EmptySquare &&
1459 board[BOARD_HEIGHT-1][BOARD_RGHT-3] == EmptySquare &&
1460 board[BOARD_HEIGHT-1][BOARD_RGHT-2] == EmptySquare &&
1461 board[BOARD_HEIGHT-1][BOARD_RGHT-1] == BlackRook &&
1462 castlingRights[3] != NoRights && /* [HGM] check rights */
1463 ( castlingRights[5] == ff || castlingRights[7] == ff ) &&
1465 (!CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff + 1, FALSE) &&
1466 !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, BOARD_RGHT-3, FALSE) &&
1467 (gameInfo.variant != VariantJanus || !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, BOARD_RGHT-2, FALSE)) &&
1468 !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff + 2, FALSE)))) {
1470 callback(board, flags,
1471 ff==BOARD_WIDTH>>1 ? BlackKingSideCastle : BlackKingSideCastleWild,
1472 BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff + ((gameInfo.boardWidth+2)>>2) + (gameInfo.variant == VariantJanus), closure);
1474 if (!(flags & F_WHITE_ON_MOVE) &&
1475 (flags & F_BLACK_QCASTLE_OK) &&
1476 board[BOARD_HEIGHT-1][ff] == bKing &&
1477 board[BOARD_HEIGHT-1][ff - 1] == EmptySquare &&
1478 board[BOARD_HEIGHT-1][ff - 2] == EmptySquare &&
1479 board[BOARD_HEIGHT-1][BOARD_LEFT+2] == EmptySquare &&
1480 board[BOARD_HEIGHT-1][BOARD_LEFT+1] == EmptySquare &&
1481 board[BOARD_HEIGHT-1][BOARD_LEFT+0] == BlackRook &&
1482 castlingRights[4] != NoRights && /* [HGM] check rights */
1483 ( castlingRights[5] == ff || castlingRights[7] == ff ) &&
1485 (!CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff - 1, FALSE) &&
1486 !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, BOARD_LEFT+3, FALSE) &&
1487 !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff - 2, FALSE)))) {
1489 callback(board, flags,
1490 ff==BOARD_WIDTH>>1 ? BlackQueenSideCastle : BlackQueenSideCastleWild,
1491 BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff - ((gameInfo.boardWidth+2)>>2), closure);
1495 if((swap = gameInfo.variant == VariantSChess) || flags & F_FRC_TYPE_CASTLING) {
1497 /* generate all potential FRC castling moves (KxR), ignoring flags */
1498 /* [HGM] test if the Rooks we find have castling rights */
1499 /* In S-Chess we generate RxK for allowed castlings, for gating at Rook square */
1502 if ((flags & F_WHITE_ON_MOVE) != 0) {
1503 ff = castlingRights[2]; /* King file if we have any rights */
1504 if(ff != NoRights && board[0][ff] == WhiteKing) {
1505 if (appData.debugMode) {
1506 fprintf(debugFP, "FRC castling, %d %d %d %d %d %d\n",
1507 castlingRights[0],castlingRights[1],ff,castlingRights[3],castlingRights[4],castlingRights[5]);
1509 ft = castlingRights[0]; /* Rook file if we have H-side rights */
1511 right = BOARD_RGHT-2;
1512 if(ff == BOARD_RGHT-2) left = right = ff-1; /* special case */
1513 for(k=left; k<=right && ft != NoRights; k++) /* first test if blocked */
1514 if(k != ft && board[0][k] != EmptySquare) ft = NoRights;
1515 for(k=left; k<right && ft != NoRights; k++) /* then if not checked */
1516 if(!ignoreCheck && CheckTest(board, flags, 0, ff, 0, k, FALSE)) ft = NoRights;
1517 if(ft != NoRights && board[0][ft] == WhiteRook) {
1518 if(flags & F_FRC_TYPE_CASTLING) callback(board, flags, WhiteHSideCastleFR, 0, ff, 0, ft, closure);
1519 if(swap) callback(board, flags, WhiteHSideCastleFR, 0, ft, 0, ff, closure);
1522 ft = castlingRights[1]; /* Rook file if we have A-side rights */
1523 left = BOARD_LEFT+2;
1525 if(ff <= BOARD_LEFT+2) { left = ff+1; right = BOARD_LEFT+3; }
1526 for(k=left; k<=right && ft != NoRights; k++) /* first test if blocked */
1527 if(k != ft && board[0][k] != EmptySquare) ft = NoRights;
1528 if(ft == 0 && ff != 1 && board[0][1] != EmptySquare) ft = NoRights; /* Rook can be blocked on b1 */
1529 if(ff > BOARD_LEFT+2)
1530 for(k=left+1; k<=right && ft != NoRights; k++) /* then if not checked */
1531 if(!ignoreCheck && CheckTest(board, flags, 0, ff, 0, k, FALSE)) ft = NoRights;
1532 if(ft != NoRights && board[0][ft] == WhiteRook) {
1533 if(flags & F_FRC_TYPE_CASTLING) callback(board, flags, WhiteASideCastleFR, 0, ff, 0, ft, closure);
1534 if(swap) callback(board, flags, WhiteASideCastleFR, 0, ft, 0, ff, closure);
1538 ff = castlingRights[5]; /* King file if we have any rights */
1539 if(ff != NoRights && board[BOARD_HEIGHT-1][ff] == BlackKing) {
1540 ft = castlingRights[3]; /* Rook file if we have H-side rights */
1542 right = BOARD_RGHT-2;
1543 if(ff == BOARD_RGHT-2) left = right = ff-1; /* special case */
1544 for(k=left; k<=right && ft != NoRights; k++) /* first test if blocked */
1545 if(k != ft && board[BOARD_HEIGHT-1][k] != EmptySquare) ft = NoRights;
1546 for(k=left; k<right && ft != NoRights; k++) /* then if not checked */
1547 if(!ignoreCheck && CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, k, FALSE)) ft = NoRights;
1548 if(ft != NoRights && board[BOARD_HEIGHT-1][ft] == BlackRook) {
1549 if(flags & F_FRC_TYPE_CASTLING) callback(board, flags, BlackHSideCastleFR, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ft, closure);
1550 if(swap) callback(board, flags, BlackHSideCastleFR, BOARD_HEIGHT-1, ft, BOARD_HEIGHT-1, ff, closure);
1553 ft = castlingRights[4]; /* Rook file if we have A-side rights */
1554 left = BOARD_LEFT+2;
1556 if(ff <= BOARD_LEFT+2) { left = ff+1; right = BOARD_LEFT+3; }
1557 for(k=left; k<=right && ft != NoRights; k++) /* first test if blocked */
1558 if(k != ft && board[BOARD_HEIGHT-1][k] != EmptySquare) ft = NoRights;
1559 if(ft == 0 && ff != 1 && board[BOARD_HEIGHT-1][1] != EmptySquare) ft = NoRights; /* Rook can be blocked on b8 */
1560 if(ff > BOARD_LEFT+2)
1561 for(k=left+1; k<=right && ft != NoRights; k++) /* then if not checked */
1562 if(!ignoreCheck && CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, k, FALSE)) ft = NoRights;
1563 if(ft != NoRights && board[BOARD_HEIGHT-1][ft] == BlackRook) {
1564 if(flags & F_FRC_TYPE_CASTLING) callback(board, flags, BlackASideCastleFR, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ft, closure);
1565 if(swap) callback(board, flags, BlackASideCastleFR, BOARD_HEIGHT-1, ft, BOARD_HEIGHT-1, ff, closure);
1582 extern void CheckTestCallback P((Board board, int flags, ChessMove kind,
1583 int rf, int ff, int rt, int ft,
1588 CheckTestCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1590 register CheckTestClosure *cl = (CheckTestClosure *) closure;
1592 if (rt == cl->rking && ft == cl->fking) {
1593 if(xqCheckers[EP_STATUS] >= 2 && xqCheckers[rf][ff]) return; // checker is piece with suspended checking power
1595 xqCheckers[rf][ff] = xqCheckers[EP_STATUS] & 1; // remember who is checking (if status == 1)
1597 if( board[EP_STATUS] == EP_ROYAL_LION && (board[rt][ft] == WhiteLion || board[rt][ft] == BlackLion)
1598 && (gameInfo.variant != VariantLion || board[rf][ff] != WhiteKing && board[rf][ff] != BlackKing) )
1599 cl->check++; // [HGM] lion: forbidden counterstrike against Lion equated to putting yourself in check
1603 /* If the player on move were to move from (rf, ff) to (rt, ft), would
1604 he leave himself in check? Or if rf == -1, is the player on move
1605 in check now? enPassant must be TRUE if the indicated move is an
1606 e.p. capture. The possibility of castling out of a check along the
1607 back rank is not accounted for (i.e., we still return nonzero), as
1608 this is illegal anyway. Return value is the number of times the
1609 king is in check. */
1611 CheckTest (Board board, int flags, int rf, int ff, int rt, int ft, int enPassant)
1613 CheckTestClosure cl;
1614 ChessSquare king = flags & F_WHITE_ON_MOVE ? WhiteKing : BlackKing;
1615 ChessSquare captured = EmptySquare, ep=0, trampled=0;
1616 int saveKill = killX;
1617 /* Suppress warnings on uninitialized variables */
1619 if(gameInfo.variant == VariantXiangqi)
1620 king = flags & F_WHITE_ON_MOVE ? WhiteWazir : BlackWazir;
1621 if(gameInfo.variant == VariantKnightmate)
1622 king = flags & F_WHITE_ON_MOVE ? WhiteUnicorn : BlackUnicorn;
1623 if(gameInfo.variant == VariantChu || gameInfo.variant == VariantShogi) { // strictly speaking this is not needed, as Chu officially has no check
1624 int r, f, k = king, royals=0, prince = flags & F_WHITE_ON_MOVE ? WhiteMonarch : BlackMonarch;
1625 if(gameInfo.variant == VariantShogi) prince -= 11; // White/BlackFalcon
1626 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++) {
1627 if(board[r][f] == k || board[r][f] == prince) {
1628 if(++royals > 1) return FALSE; // no check if we have two royals (ignores double captureby Lion!)
1629 king = board[r][f]; // remember hich one we had
1636 captured = board[rf][ft];
1637 board[rf][ft] = EmptySquare;
1639 captured = board[rt][ft];
1640 if(killX >= 0) { trampled = board[killY][killX]; board[killY][killX] = EmptySquare; killX = -1; }
1642 if(rf == DROP_RANK) board[rt][ft] = ff; else { // [HGM] drop
1643 board[rt][ft] = board[rf][ff];
1644 if(rf != rt || ff != ft) board[rf][ff] = EmptySquare;
1646 ep = board[EP_STATUS];
1647 if( captured == WhiteLion || captured == BlackLion ) { // [HGM] lion: Chu Lion-capture rules
1648 ChessSquare victim = killX < 0 ? EmptySquare : trampled;
1649 if( (board[rt][ft] == WhiteLion || board[rt][ft] == BlackLion) && // capturer is Lion
1650 (ff - ft > 1 || ft - ff > 1 || rf - rt > 1 || rt - rf > 1) && // captures from a distance
1651 (victim == EmptySquare || victim == WhitePawn || victim == BlackPawn) ) // no or worthless 'bridge'
1652 board[EP_STATUS] = EP_ROYAL_LION; // on distant Lion x Lion victim must not be pseudo-legally protected
1656 /* For compatibility with ICS wild 9, we scan the board in the
1657 order a1, a2, a3, ... b1, b2, ..., h8 to find the first king,
1658 and we test only whether that one is in check. */
1659 for (cl.fking = BOARD_LEFT+0; cl.fking < BOARD_RGHT; cl.fking++)
1660 for (cl.rking = 0; cl.rking < BOARD_HEIGHT; cl.rking++) {
1661 if (board[cl.rking][cl.fking] == king) {
1663 if(gameInfo.variant == VariantXiangqi) {
1664 /* [HGM] In Xiangqi opposing Kings means check as well */
1666 dir = (king >= BlackPawn) ? -1 : 1;
1667 for( i=cl.rking+dir; i>=0 && i<BOARD_HEIGHT &&
1668 board[i][cl.fking] == EmptySquare; i+=dir );
1669 if(i>=0 && i<BOARD_HEIGHT &&
1670 board[i][cl.fking] == (dir>0 ? BlackWazir : WhiteWazir) )
1673 GenPseudoLegal(board, flags ^ F_WHITE_ON_MOVE, CheckTestCallback, (VOIDSTAR) &cl, EmptySquare);
1674 if(gameInfo.variant != VariantSpartan || cl.check == 0) // in Spartan Chess go on to test if other King is checked too
1675 goto undo_move; /* 2-level break */
1682 if(rf != DROP_RANK) // [HGM] drop
1683 board[rf][ff] = board[rt][ft];
1685 board[rf][ft] = captured;
1686 board[rt][ft] = EmptySquare;
1688 if(saveKill >= 0) board[killY][killX] = trampled, killX = saveKill;
1689 board[rt][ft] = captured;
1691 board[EP_STATUS] = ep;
1694 return cl.fking < BOARD_RGHT ? cl.check : 1000; // [HGM] atomic: return 1000 if we have no king
1698 HasLion (Board board, int flags)
1700 int lion = F_WHITE_ON_MOVE & flags ? WhiteLion : BlackLion;
1702 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++)
1703 if(board[r][f] == lion) return 1;
1708 LegalDrop (Board board, int flags, ChessSquare piece, int rt, int ft)
1709 { // [HGM] put drop legality testing in separate routine for clarity
1711 if(appData.debugMode) fprintf(debugFP, "LegalDrop: %d @ %d,%d)\n", piece, ft, rt);
1712 if(board[rt][ft] != EmptySquare) return ImpossibleMove; // must drop to empty square
1713 n = PieceToNumber(piece);
1714 if((gameInfo.holdingsWidth == 0 || (flags & F_WHITE_ON_MOVE ? board[n][BOARD_WIDTH-1] : board[BOARD_HEIGHT-1-n][0]) != piece)
1715 && gameInfo.variant != VariantBughouse) // in bughouse we don't check for availability, because ICS doesn't always tell us
1716 return ImpossibleMove; // piece not available
1717 if(gameInfo.variant == VariantShogi) { // in Shogi lots of drops are forbidden!
1718 if((piece == WhitePawn || piece == WhiteQueen) && rt == BOARD_HEIGHT-1 ||
1719 (piece == BlackPawn || piece == BlackQueen) && rt == 0 ||
1720 piece == WhiteKnight && rt > BOARD_HEIGHT-3 ||
1721 piece == BlackKnight && rt < 2 ) return IllegalMove; // e.g. where dropped piece has no moves
1722 if(piece == WhitePawn || piece == BlackPawn) {
1723 int r, max = 1 + (BOARD_HEIGHT == 7); // two Pawns per file in Tori!
1724 for(r=1; r<BOARD_HEIGHT-1; r++)
1725 if(!(max -= (board[r][ft] == piece))) return IllegalMove; // or there already is a Pawn in file
1726 // should still test if we mate with this Pawn
1728 } else if(gameInfo.variant == VariantSChess) { // only back-rank drops
1729 if (rt != (piece < BlackPawn ? 0 : BOARD_HEIGHT-1)) return IllegalMove;
1731 if( (piece == WhitePawn || piece == BlackPawn) &&
1732 (rt == 0 || rt == BOARD_HEIGHT -1 ) )
1733 return IllegalMove; /* no pawn drops on 1st/8th */
1735 if(appData.debugMode) fprintf(debugFP, "LegalDrop: %d @ %d,%d)\n", piece, ft, rt);
1736 if (!(flags & F_IGNORE_CHECK) &&
1737 CheckTest(board, flags, DROP_RANK, piece, rt, ft, FALSE) ) return IllegalMove;
1738 return flags & F_WHITE_ON_MOVE ? WhiteDrop : BlackDrop;
1741 extern void LegalityTestCallback P((Board board, int flags, ChessMove kind,
1742 int rf, int ff, int rt, int ft,
1746 LegalityTestCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1748 register LegalityTestClosure *cl = (LegalityTestClosure *) closure;
1750 if(board[rt][ft] != EmptySquare || kind==WhiteCapturesEnPassant || kind==BlackCapturesEnPassant)
1751 cl->captures++; // [HGM] losers: count legal captures
1752 if (rf == cl->rf && ff == cl->ff && rt == cl->rt && ft == cl->ft)
1757 LegalityTest (Board board, int flags, int rf, int ff, int rt, int ft, int promoChar)
1759 LegalityTestClosure cl; ChessSquare piece, filterPiece;
1761 if(quickFlag) flags = flags & ~1 | quickFlag & 1; // [HGM] speed: in quick mode quickFlag specifies side-to-move.
1762 if(rf == DROP_RANK) return LegalDrop(board, flags, ff, rt, ft);
1763 piece = filterPiece = board[rf][ff];
1764 if(PieceToChar(piece) == '~') filterPiece = DEMOTED piece;
1766 /* [HGM] Cobra and Falcon are wildcard pieces; consider all their moves legal */
1767 /* (perhaps we should disallow moves that obviously leave us in check?) */
1768 if((piece == WhiteFalcon || piece == BlackFalcon ||
1769 piece == WhiteCobra || piece == BlackCobra) && gameInfo.variant != VariantChu && !pieceDesc[piece])
1770 return CheckTest(board, flags, rf, ff, rt, ft, FALSE) ? IllegalMove : NormalMove;
1774 cl.rt = rFilter = rt; // [HGM] speed: filter on to-square
1775 cl.ft = fFilter = ft;
1776 cl.kind = IllegalMove;
1777 cl.captures = 0; // [HGM] losers: prepare to count legal captures.
1778 if(flags & F_MANDATORY_CAPTURE) filterPiece = EmptySquare; // [HGM] speed: do not filter in suicide, to find all captures
1779 GenLegal(board, flags, LegalityTestCallback, (VOIDSTAR) &cl, filterPiece);
1780 if((flags & F_MANDATORY_CAPTURE) && cl.captures && board[rt][ft] == EmptySquare
1781 && cl.kind != WhiteCapturesEnPassant && cl.kind != BlackCapturesEnPassant)
1782 return(IllegalMove); // [HGM] losers: if there are legal captures, non-capts are illegal
1784 if(promoChar == 'x') promoChar = NULLCHAR; // [HGM] is this ever the case?
1785 if(gameInfo.variant == VariantSChess && promoChar && promoChar != '=' && board[rf][ff] != WhitePawn && board[rf][ff] != BlackPawn) {
1786 if(board[rf][ff] < BlackPawn) { // white
1787 if(rf != 0) return IllegalMove; // must be on back rank
1788 if(!(board[VIRGIN][ff] & VIRGIN_W)) return IllegalMove; // non-virgin
1789 if(board[PieceToNumber(CharToPiece(ToUpper(promoChar)))][BOARD_WIDTH-2] == 0) return ImpossibleMove;// must be in stock
1790 if(cl.kind == WhiteHSideCastleFR && (ff == BOARD_RGHT-2 || ff == BOARD_RGHT-3)) return ImpossibleMove;
1791 if(cl.kind == WhiteASideCastleFR && (ff == BOARD_LEFT+2 || ff == BOARD_LEFT+3)) return ImpossibleMove;
1793 if(rf != BOARD_HEIGHT-1) return IllegalMove;
1794 if(!(board[VIRGIN][ff] & VIRGIN_B)) return IllegalMove; // non-virgin
1795 if(board[BOARD_HEIGHT-1-PieceToNumber(CharToPiece(ToLower(promoChar)))][1] == 0) return ImpossibleMove;
1796 if(cl.kind == BlackHSideCastleFR && (ff == BOARD_RGHT-2 || ff == BOARD_RGHT-3)) return ImpossibleMove;
1797 if(cl.kind == BlackASideCastleFR && (ff == BOARD_LEFT+2 || ff == BOARD_LEFT+3)) return ImpossibleMove;
1800 if(gameInfo.variant == VariantChu) {
1801 if(cl.kind != NormalMove || promoChar == NULLCHAR || promoChar == '=') return cl.kind;
1802 if(promoChar != '+')
1803 return CharToPiece(promoChar) == EmptySquare ? ImpossibleMove : IllegalMove;
1804 if(PieceToChar(CHUPROMOTED board[rf][ff]) != '+') return ImpossibleMove;
1805 return flags & F_WHITE_ON_MOVE ? WhitePromotion : BlackPromotion;
1807 if(gameInfo.variant == VariantShogi) {
1808 /* [HGM] Shogi promotions. '=' means defer */
1809 if(rf != DROP_RANK && cl.kind == NormalMove) {
1810 ChessSquare piece = board[rf][ff];
1812 if(promoChar == PieceToChar(BlackQueen)) promoChar = NULLCHAR; /* [HGM] Kludge */
1813 if(promoChar == 'd' && (piece == WhiteRook || piece == BlackRook) ||
1814 promoChar == 'h' && (piece == WhiteBishop || piece == BlackBishop) ||
1815 promoChar == 'g' && (piece <= WhiteFerz || piece <= BlackFerz && piece >= BlackPawn) )
1816 promoChar = '+'; // allowed ICS notations
1817 if(appData.debugMode)fprintf(debugFP,"SHOGI promoChar = %c\n", promoChar ? promoChar : '-');
1818 if(promoChar != NULLCHAR && promoChar != '+' && promoChar != '=')
1819 return CharToPiece(promoChar) == EmptySquare ? ImpossibleMove : IllegalMove;
1820 else if(flags & F_WHITE_ON_MOVE) {
1821 if( (int) piece < (int) WhiteWazir &&
1822 (rf >= BOARD_HEIGHT - BOARD_HEIGHT/3 || rt >= BOARD_HEIGHT - BOARD_HEIGHT/3) ) {
1823 if( (piece == WhitePawn || piece == WhiteQueen) && rt > BOARD_HEIGHT-2 ||
1824 piece == WhiteKnight && rt > BOARD_HEIGHT-3) /* promotion mandatory */
1825 cl.kind = promoChar == '=' ? IllegalMove : WhitePromotion;
1826 else /* promotion optional, default is defer */
1827 cl.kind = promoChar == '+' ? WhitePromotion : WhiteNonPromotion;
1828 } else cl.kind = promoChar == '+' ? IllegalMove : NormalMove;
1830 if( (int) piece < (int) BlackWazir && (rf < BOARD_HEIGHT/3 || rt < BOARD_HEIGHT/3) ) {
1831 if( (piece == BlackPawn || piece == BlackQueen) && rt < 1 ||
1832 piece == BlackKnight && rt < 2 ) /* promotion obligatory */
1833 cl.kind = promoChar == '=' ? IllegalMove : BlackPromotion;
1834 else /* promotion optional, default is defer */
1835 cl.kind = promoChar == '+' ? BlackPromotion : BlackNonPromotion;
1836 } else cl.kind = promoChar == '+' ? IllegalMove : NormalMove;
1840 if (promoChar != NULLCHAR) {
1841 if(cl.kind == NormalMove && promoChar == '+') { // allow shogi-style promotion is pieceToChar specifies them
1842 ChessSquare piece = board[rf][ff];
1843 if(piece < BlackPawn ? piece > WhiteMan : piece > BlackMan) return ImpossibleMove; // already promoted
1844 // should test if in zone, really
1845 if(gameInfo.variant == VariantChuChess && (piece == WhiteKnight || piece == BlackKnight) && HasLion(board, flags))
1847 if(PieceToChar(PROMOTED piece) == '+') return flags & F_WHITE_ON_MOVE ? WhitePromotion : BlackPromotion;
1849 if(promoChar == '=') cl.kind = IllegalMove; else // [HGM] shogi: no deferred promotion outside Shogi
1850 if (cl.kind == WhitePromotion || cl.kind == BlackPromotion) {
1851 ChessSquare piece = CharToPiece(flags & F_WHITE_ON_MOVE ? ToUpper(promoChar) : ToLower(promoChar));
1852 if(piece == EmptySquare)
1853 cl.kind = ImpossibleMove; // non-existing piece
1854 if(gameInfo.variant == VariantChuChess && promoChar == 'l' && HasLion(board, flags)) {
1855 cl.kind = IllegalMove; // no two Lions
1856 } else if(gameInfo.variant == VariantSpartan && cl.kind == BlackPromotion ) {
1857 if(promoChar != PieceToChar(BlackKing)) {
1858 if(CheckTest(board, flags, rf, ff, rt, ft, FALSE)) cl.kind = IllegalMove; // [HGM] spartan: only promotion to King was possible
1859 if(piece == BlackLance) cl.kind = ImpossibleMove;
1860 } else { // promotion to King allowed only if we do not have two yet
1861 int r, f, kings = 0;
1862 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++) kings += (board[r][f] == BlackKing);
1863 if(kings == 2) cl.kind = IllegalMove;
1865 } else if(piece == WhitePawn && rt == BOARD_HEIGHT-1 ||
1866 piece == BlackPawn && rt == 0) cl.kind = IllegalMove; // cannot stay Pawn on last rank in any variant
1867 else if((piece == WhiteUnicorn || piece == BlackUnicorn) && gameInfo.variant == VariantKnightmate)
1868 cl.kind = IllegalMove; // promotion to Royal Knight not allowed
1869 else if((piece == WhiteKing || piece == BlackKing) && gameInfo.variant != VariantSuicide && gameInfo.variant != VariantGiveaway)
1870 cl.kind = IllegalMove; // promotion to King usually not allowed
1872 cl.kind = IllegalMove;
1882 extern void MateTestCallback P((Board board, int flags, ChessMove kind,
1883 int rf, int ff, int rt, int ft,
1887 MateTestCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1889 register MateTestClosure *cl = (MateTestClosure *) closure;
1894 /* Return MT_NONE, MT_CHECK, MT_CHECKMATE, or MT_STALEMATE */
1896 MateTest (Board board, int flags)
1899 int inCheck, r, f, myPieces=0, hisPieces=0, nrKing=0;
1900 ChessSquare king = flags & F_WHITE_ON_MOVE ? WhiteKing : BlackKing;
1902 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++) {
1903 // [HGM] losers: Count pieces and kings, to detect other unorthodox winning conditions
1904 nrKing += (board[r][f] == king); // stm has king
1905 if( board[r][f] != EmptySquare ) {
1906 if((int)board[r][f] <= (int)king && (int)board[r][f] >= (int)king - (int)WhiteKing + (int)WhitePawn)
1911 switch(gameInfo.variant) { // [HGM] losers: extinction wins
1912 case VariantShatranj:
1913 if(hisPieces == 1) return myPieces > 1 ? MT_BARE : MT_DRAW;
1917 if(nrKing == 0) return MT_NOKING;
1920 if(myPieces == 1) return MT_BARE;
1923 inCheck = GenLegal(board, flags, MateTestCallback, (VOIDSTAR) &cl, EmptySquare);
1924 // [HGM] 3check: yet to do!
1926 return inCheck ? MT_CHECK : MT_NONE;
1928 if(gameInfo.holdingsWidth && gameInfo.variant != VariantSuper && gameInfo.variant != VariantGreat
1929 && gameInfo.variant != VariantSChess && gameInfo.variant != VariantGrand) { // drop game
1930 int r, f, n, holdings = flags & F_WHITE_ON_MOVE ? BOARD_WIDTH-1 : 0;
1931 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++) if(board[r][f] == EmptySquare) // all empty squares
1932 for(n=0; n<BOARD_HEIGHT; n++) // all pieces in hand
1933 if(board[n][holdings] != EmptySquare) {
1934 int moveType = LegalDrop(board, flags, board[n][holdings], r, f);
1935 if(moveType == WhiteDrop || moveType == BlackDrop) return (inCheck ? MT_CHECK : MT_NONE); // we have legal drop
1938 if(gameInfo.variant == VariantSuicide) // [HGM] losers: always stalemate, since no check, but result varies
1939 return myPieces == hisPieces ? MT_STALEMATE :
1940 myPieces > hisPieces ? MT_STAINMATE : MT_STEALMATE;
1941 else if(gameInfo.variant == VariantLosers) return inCheck ? MT_TRICKMATE : MT_STEALMATE;
1942 else if(gameInfo.variant == VariantGiveaway) return MT_STEALMATE; // no check exists, stalemated = win
1944 return inCheck ? MT_CHECKMATE
1945 : (gameInfo.variant == VariantXiangqi || gameInfo.variant == VariantShatranj || IS_SHOGI(gameInfo.variant)) ?
1946 MT_STAINMATE : MT_STALEMATE;
1951 extern void DisambiguateCallback P((Board board, int flags, ChessMove kind,
1952 int rf, int ff, int rt, int ft,
1956 DisambiguateCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1958 register DisambiguateClosure *cl = (DisambiguateClosure *) closure;
1959 int wildCard = FALSE; ChessSquare piece = board[rf][ff];
1961 // [HGM] wild: for wild-card pieces rt and rf are dummies
1962 if(piece == WhiteFalcon || piece == BlackFalcon ||
1963 piece == WhiteCobra || piece == BlackCobra)
1966 if ((cl->pieceIn == EmptySquare || cl->pieceIn == board[rf][ff]
1967 || PieceToChar(board[rf][ff]) == '~'
1968 && cl->pieceIn == (ChessSquare)(DEMOTED board[rf][ff])
1970 (cl->rfIn == -1 || cl->rfIn == rf) &&
1971 (cl->ffIn == -1 || cl->ffIn == ff) &&
1972 (cl->rtIn == -1 || cl->rtIn == rt || wildCard) &&
1973 (cl->ftIn == -1 || cl->ftIn == ft || wildCard)) {
1975 if(cl->count && rf == cl->rf && ff == cl->ff) return; // duplicate move
1978 if(cl->count == 1 || board[rt][ft] != EmptySquare) {
1979 // [HGM] oneclick: if multiple moves, be sure we remember capture
1980 cl->piece = board[rf][ff];
1983 cl->rt = wildCard ? cl->rtIn : rt;
1984 cl->ft = wildCard ? cl->ftIn : ft;
1987 cl->captures += (board[rt][ft] != EmptySquare); // [HGM] oneclick: count captures
1992 Disambiguate (Board board, int flags, DisambiguateClosure *closure)
1994 int illegal = 0; char c = closure->promoCharIn;
1996 if(quickFlag) flags = flags & ~1 | quickFlag & 1; // [HGM] speed: in quick mode quickFlag specifies side-to-move.
1997 closure->count = closure->captures = 0;
1998 closure->rf = closure->ff = closure->rt = closure->ft = 0;
1999 closure->kind = ImpossibleMove;
2000 rFilter = closure->rtIn; // [HGM] speed: only consider moves to given to-square
2001 fFilter = closure->ftIn;
2002 if(quickFlag) { // [HGM] speed: try without check test first, because if that is not ambiguous, we are happy
2003 GenLegal(board, flags|F_IGNORE_CHECK, DisambiguateCallback, (VOIDSTAR) closure, closure->pieceIn);
2004 if(closure->count > 1) { // gamble did not pay off. retry with check test to resolve ambiguity
2005 closure->count = closure->captures = 0;
2006 closure->rf = closure->ff = closure->rt = closure->ft = 0;
2007 closure->kind = ImpossibleMove;
2008 GenLegal(board, flags, DisambiguateCallback, (VOIDSTAR) closure, closure->pieceIn); // [HGM] speed: only pieces of requested type
2011 GenLegal(board, flags, DisambiguateCallback, (VOIDSTAR) closure, closure->pieceIn); // [HGM] speed: only pieces of requested type
2012 if (closure->count == 0) {
2013 /* See if it's an illegal move due to check */
2015 GenLegal(board, flags|F_IGNORE_CHECK, DisambiguateCallback, (VOIDSTAR) closure, closure->pieceIn);
2016 if (closure->count == 0) {
2017 /* No, it's not even that */
2018 if(!appData.testLegality && closure->pieceIn != EmptySquare) {
2019 int f, r; // if there is only a single piece of the requested type on the board, use that
2020 closure->rt = closure->rtIn, closure->ft = closure->ftIn;
2021 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++)
2022 if(board[r][f] == closure->pieceIn) closure->count++, closure->rf = r, closure->ff = f;
2023 if(closure->count > 1) illegal = 0; // ambiguous
2025 if(closure->count == 0) {
2026 if (appData.debugMode) { int i, j;
2027 for(i=BOARD_HEIGHT-1; i>=0; i--) {
2028 for(j=0; j<BOARD_WIDTH; j++)
2029 fprintf(debugFP, "%3d", (int) board[i][j]);
2030 fprintf(debugFP, "\n");
2036 } else if(pieceDefs && closure->count > 1) { // [HGM] gen: move is ambiguous under engine-defined rules
2037 DisambiguateClosure spare = *closure;
2038 pieceDefs = FALSE; spare.count = 0; // See if the (erroneous) built-in rules would resolve that
2039 GenLegal(board, flags, DisambiguateCallback, (VOIDSTAR) &spare, closure->pieceIn);
2040 if(spare.count == 1) *closure = spare; // It does, so use those in stead (game from file saved before gen patch?)
2044 if (c == 'x') c = NULLCHAR; // get rid of any 'x' (which should never happen?)
2045 if(gameInfo.variant == VariantSChess && c && c != '=' && closure->piece != WhitePawn && closure->piece != BlackPawn) {
2046 if(closure->piece < BlackPawn) { // white
2047 if(closure->rf != 0) closure->kind = IllegalMove; // must be on back rank
2048 if(!(board[VIRGIN][closure->ff] & VIRGIN_W)) closure->kind = IllegalMove; // non-virgin
2049 if(board[PieceToNumber(CharToPiece(ToUpper(c)))][BOARD_WIDTH-2] == 0) closure->kind = ImpossibleMove;// must be in stock
2050 if(closure->kind == WhiteHSideCastleFR && (closure->ff == BOARD_RGHT-2 || closure->ff == BOARD_RGHT-3)) closure->kind = ImpossibleMove;
2051 if(closure->kind == WhiteASideCastleFR && (closure->ff == BOARD_LEFT+2 || closure->ff == BOARD_LEFT+3)) closure->kind = ImpossibleMove;
2053 if(closure->rf != BOARD_HEIGHT-1) closure->kind = IllegalMove;
2054 if(!(board[VIRGIN][closure->ff] & VIRGIN_B)) closure->kind = IllegalMove; // non-virgin
2055 if(board[BOARD_HEIGHT-1-PieceToNumber(CharToPiece(ToLower(c)))][1] == 0) closure->kind = ImpossibleMove;
2056 if(closure->kind == BlackHSideCastleFR && (closure->ff == BOARD_RGHT-2 || closure->ff == BOARD_RGHT-3)) closure->kind = ImpossibleMove;
2057 if(closure->kind == BlackASideCastleFR && (closure->ff == BOARD_LEFT+2 || closure->ff == BOARD_LEFT+3)) closure->kind = ImpossibleMove;
2060 if(gameInfo.variant == VariantChu) {
2061 if(c == '+') closure->kind = (flags & F_WHITE_ON_MOVE ? WhitePromotion : BlackPromotion); // for now, accept any
2063 if(gameInfo.variant == VariantShogi) {
2064 /* [HGM] Shogi promotions. On input, '=' means defer, '+' promote. Afterwards, c is set to '+' for promotions, NULL other */
2065 if(closure->rfIn != DROP_RANK && closure->kind == NormalMove) {
2066 ChessSquare piece = closure->piece;
2067 if (c == 'd' && (piece == WhiteRook || piece == BlackRook) ||
2068 c == 'h' && (piece == WhiteBishop || piece == BlackBishop) ||
2069 c == 'g' && (piece <= WhiteFerz || piece <= BlackFerz && piece >= BlackPawn) )
2070 c = '+'; // allowed ICS notations
2071 if(c != NULLCHAR && c != '+' && c != '=') closure->kind = IllegalMove; // otherwise specifying a piece is illegal
2072 else if(flags & F_WHITE_ON_MOVE) {
2073 if( (int) piece < (int) WhiteWazir &&
2074 (closure->rf >= BOARD_HEIGHT-(BOARD_HEIGHT/3) || closure->rt >= BOARD_HEIGHT-(BOARD_HEIGHT/3)) ) {
2075 if( (piece == WhitePawn || piece == WhiteQueen) && closure->rt > BOARD_HEIGHT-2 ||
2076 piece == WhiteKnight && closure->rt > BOARD_HEIGHT-3) /* promotion mandatory */
2077 closure->kind = c == '=' ? IllegalMove : WhitePromotion;
2078 else /* promotion optional, default is defer */
2079 closure->kind = c == '+' ? WhitePromotion : WhiteNonPromotion;
2080 } else closure->kind = c == '+' ? IllegalMove : NormalMove;
2082 if( (int) piece < (int) BlackWazir && (closure->rf < BOARD_HEIGHT/3 || closure->rt < BOARD_HEIGHT/3) ) {
2083 if( (piece == BlackPawn || piece == BlackQueen) && closure->rt < 1 ||
2084 piece == BlackKnight && closure->rt < 2 ) /* promotion obligatory */
2085 closure->kind = c == '=' ? IllegalMove : BlackPromotion;
2086 else /* promotion optional, default is defer */
2087 closure->kind = c == '+' ? BlackPromotion : BlackNonPromotion;
2088 } else closure->kind = c == '+' ? IllegalMove : NormalMove;
2091 if(closure->kind == WhitePromotion || closure->kind == BlackPromotion) c = '+'; else
2092 if(closure->kind == WhiteNonPromotion || closure->kind == BlackNonPromotion) c = '=';
2094 if (closure->kind == WhitePromotion || closure->kind == BlackPromotion) {
2095 if(c == NULLCHAR) { // missing promoChar on mandatory promotion; use default for variant
2096 if(gameInfo.variant == VariantShatranj || gameInfo.variant == VariantCourier ||
2097 gameInfo.variant == VariantMakruk || gameInfo.variant == VariantASEAN)
2098 c = PieceToChar(BlackFerz);
2099 else if(gameInfo.variant == VariantGreat)
2100 c = PieceToChar(BlackMan);
2101 else if(gameInfo.variant == VariantGrand)
2102 closure->kind = closure->rt != 0 && closure->rt != BOARD_HEIGHT-1 ? NormalMove : AmbiguousMove; // no default in Grand Chess
2104 c = PieceToChar(BlackQueen);
2105 } else if(c == '=') closure->kind = IllegalMove; // no deferral outside Shogi
2106 else if(c == 'l' && gameInfo.variant == VariantChuChess && HasLion(board, flags)) closure->kind = IllegalMove;
2107 } else if (c == '+') { // '+' outside shogi, check if pieceToCharTable enabled it
2108 ChessSquare p = closure->piece;
2109 if(p > WhiteMan && p < BlackPawn || p > BlackMan || PieceToChar(PROMOTED p) != '+')
2110 closure->kind = ImpossibleMove; // used on non-promotable piece
2111 else if(gameInfo.variant == VariantChuChess && HasLion(board, flags)) closure->kind = IllegalMove;
2112 } else if (c != NULLCHAR) closure->kind = IllegalMove;
2114 closure->promoChar = ToLower(c); // this can be NULLCHAR! Note we keep original promoChar even if illegal.
2115 if(c != '+' && c != '=' && c != NULLCHAR && CharToPiece(flags & F_WHITE_ON_MOVE ? ToUpper(c) : ToLower(c)) == EmptySquare)
2116 closure->kind = ImpossibleMove; // but we cannot handle non-existing piece types!
2117 if (closure->count > 1) {
2118 closure->kind = AmbiguousMove;
2121 /* Note: If more than one illegal move matches, but no legal
2122 moves, we return IllegalMove, not AmbiguousMove. Caller
2123 can look at closure->count to detect this.
2125 closure->kind = IllegalMove;
2139 } CoordsToAlgebraicClosure;
2141 extern void CoordsToAlgebraicCallback P((Board board, int flags,
2142 ChessMove kind, int rf, int ff,
2143 int rt, int ft, VOIDSTAR closure));
2146 CoordsToAlgebraicCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
2148 register CoordsToAlgebraicClosure *cl =
2149 (CoordsToAlgebraicClosure *) closure;
2151 if ((rt == cl->rt && ft == cl->ft || rt == rf && ft == ff) && // [HGM] null move matches any toSquare
2152 (board[rf][ff] == cl->piece
2153 || PieceToChar(board[rf][ff]) == '~' &&
2154 (ChessSquare) (DEMOTED board[rf][ff]) == cl->piece)
2158 cl->kind = kind; /* this is the move we want */
2160 cl->file++; /* need file to rule out this move */
2164 cl->rank++; /* need rank to rule out this move */
2166 cl->either++; /* rank or file will rule out this move */
2172 /* Convert coordinates to normal algebraic notation.
2173 promoChar must be NULLCHAR or 'x' if not a promotion.
2176 CoordsToAlgebraic (Board board, int flags, int rf, int ff, int rt, int ft, int promoChar, char out[MOVE_LEN])
2180 char *outp = out, c, capture;
2181 CoordsToAlgebraicClosure cl;
2183 if (rf == DROP_RANK) {
2184 if(ff == EmptySquare) { strncpy(outp, "--",3); return NormalMove; } // [HGM] pass
2185 /* Bughouse piece drop */
2186 *outp++ = ToUpper(PieceToChar((ChessSquare) ff));
2191 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2193 return (flags & F_WHITE_ON_MOVE) ? WhiteDrop : BlackDrop;
2196 if (promoChar == 'x') promoChar = NULLCHAR;
2197 piece = board[rf][ff];
2198 if(PieceToChar(piece)=='~') piece = (ChessSquare)(DEMOTED piece);
2203 kind = LegalityTest(board, flags, rf, ff, rt, ft, promoChar);
2204 if (kind == IllegalMove && !(flags&F_IGNORE_CHECK)) {
2205 /* Keep short notation if move is illegal only because it
2206 leaves the player in check, but still return IllegalMove */
2207 kind = LegalityTest(board, flags|F_IGNORE_CHECK, rf, ff, rt, ft, promoChar);
2208 if (kind == IllegalMove) break;
2213 capture = board[rt][ft] != EmptySquare || kind == WhiteCapturesEnPassant || kind == BlackCapturesEnPassant;
2214 if (ff == ft && !capture) { /* [HGM] Xiangqi has straight noncapts! */
2215 /* Non-capture; use style "e5" */
2218 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2220 /* Capture; use style "exd5" */
2222 *outp++ = 'x'; /* [HGM] Xiangqi has sideway noncaptures across river! */
2226 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2228 /* Use promotion suffix style "=Q" */
2230 if (promoChar != NULLCHAR) {
2231 if(IS_SHOGI(gameInfo.variant)) {
2232 /* [HGM] ... but not in Shogi! */
2233 *outp++ = promoChar == '=' ? '=' : '+';
2236 *outp++ = ToUpper(promoChar);
2245 /* Fabien moved code: FRC castling first (if KxR), wild castling second */
2246 /* Code added by Tord: FRC castling. */
2247 if((piece == WhiteKing && board[rt][ft] == WhiteRook) ||
2248 (piece == BlackKing && board[rt][ft] == BlackRook)) {
2250 safeStrCpy(out, "O-O", MOVE_LEN);
2252 safeStrCpy(out, "O-O-O", MOVE_LEN);
2253 return LegalityTest(board, flags, rf, ff, rt, ft, promoChar);
2255 /* End of code added by Tord */
2256 /* Test for castling or ICS wild castling */
2257 /* Use style "O-O" (oh-oh) for PGN compatibility */
2258 else if (rf == rt &&
2259 rf == ((piece == WhiteKing) ? 0 : BOARD_HEIGHT-1) &&
2260 (ft - ff > 1 || ff - ft > 1) && // No castling if legal King move (on narrow boards!)
2261 ((ff == BOARD_WIDTH>>1 && (ft == BOARD_LEFT+2 || ft == BOARD_RGHT-2)) ||
2262 (ff == (BOARD_WIDTH-1)>>1 && (ft == BOARD_LEFT+1 || ft == BOARD_RGHT-3)))) {
2263 if(ft==BOARD_LEFT+1 || ft==BOARD_RGHT-2)
2264 snprintf(out, MOVE_LEN, "O-O%c%c", promoChar ? '/' : 0, ToUpper(promoChar));
2266 snprintf(out, MOVE_LEN, "O-O-O%c%c", promoChar ? '/' : 0, ToUpper(promoChar));
2268 /* This notation is always unambiguous, unless there are
2269 kings on both the d and e files, with "wild castling"
2270 possible for the king on the d file and normal castling
2271 possible for the other. ICS rules for wild 9
2272 effectively make castling illegal for either king in
2273 this situation. So I am not going to worry about it;
2274 I'll just generate an ambiguous O-O in this case.
2276 return LegalityTest(board, flags, rf, ff, rt, ft, promoChar);
2279 /* else fall through */
2284 cl.rt = rFilter = rt; // [HGM] speed: filter on to-square
2285 cl.ft = fFilter = ft;
2287 cl.kind = IllegalMove;
2288 cl.rank = cl.file = cl.either = 0;
2289 c = PieceToChar(piece) ;
2290 GenLegal(board, flags, CoordsToAlgebraicCallback, (VOIDSTAR) &cl, c!='~' ? piece : (DEMOTED piece)); // [HGM] speed
2292 if (cl.kind == IllegalMove && !(flags&F_IGNORE_CHECK)) {
2293 /* Generate pretty moves for moving into check, but
2294 still return IllegalMove.
2296 GenLegal(board, flags|F_IGNORE_CHECK, CoordsToAlgebraicCallback, (VOIDSTAR) &cl, c!='~' ? piece : (DEMOTED piece));
2297 if (cl.kind == IllegalMove) break;
2298 cl.kind = IllegalMove;
2301 /* Style is "Nf3" or "Nxf7" if this is unambiguous,
2302 else "Ngf3" or "Ngxf7",
2303 else "N1f3" or "N5xf7",
2304 else "Ng1f3" or "Ng5xf7".
2306 if( c == '~' || c == '+') {
2307 /* [HGM] print nonexistent piece as its demoted version */
2308 piece = (ChessSquare) (DEMOTED piece - 11*(gameInfo.variant == VariantChu));
2310 if(c=='+') *outp++ = c;
2311 *outp++ = ToUpper(PieceToChar(piece));
2313 if (cl.file || (cl.either && !cl.rank)) {
2319 else { *outp++ = (rf+ONE-'0')/10 + '0';*outp++ = (rf+ONE-'0')%10 + '0'; }
2322 if(board[rt][ft] != EmptySquare)
2328 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2329 if (IS_SHOGI(gameInfo.variant)) {
2330 /* [HGM] in Shogi non-pawns can promote */
2331 *outp++ = promoChar; // Don't bother to correct move type, return value is never used!
2333 else if (gameInfo.variant == VariantChuChess && promoChar ||
2334 gameInfo.variant != VariantSuper && promoChar &&
2335 (piece == WhiteLance || piece == BlackLance) ) { // Lance sometimes represents Pawn
2337 *outp++ = ToUpper(promoChar);
2339 else if (gameInfo.variant == VariantSChess && promoChar) { // and in S-Chess we have gating
2341 *outp++ = ToUpper(promoChar);
2347 /* Moving a nonexistent piece */
2351 /* Not a legal move, even ignoring check.
2352 If there was a piece on the from square,
2353 use style "Ng1g3" or "Ng1xe8";
2354 if there was a pawn or nothing (!),
2355 use style "g1g3" or "g1xe8". Use "x"
2356 if a piece was on the to square, even
2357 a piece of the same color.
2361 if (piece != EmptySquare && piece != WhitePawn && piece != BlackPawn) {
2363 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<=BOARD_RGHT; f++)
2364 c += (board[r][f] == piece); // count on-board pieces of given type
2365 *outp++ = ToUpper(PieceToChar(piece));
2367 if(c != 1) { // [HGM] but if there is only one piece of the mentioned type, no from-square, thank you!
2371 else { *outp++ = (rf+ONE-'0')/10 + '0';*outp++ = (rf+ONE-'0')%10 + '0'; }
2373 if (board[rt][ft] != EmptySquare) *outp++ = 'x';
2377 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2378 /* Use promotion suffix style "=Q" */
2379 if (promoChar != NULLCHAR && promoChar != 'x') {
2381 *outp++ = ToUpper(promoChar);
2388 // [HGM] XQ: the following code serves to detect perpetual chasing (Asian rules)
2397 // I guess the following variables logically belong in the closure too, but I was too lazy and used globals
2399 int preyStackPointer, chaseStackPointer;
2402 unsigned char rf, ff, rt, ft;
2406 unsigned char rank, file;
2412 // there are three new callbacks for use with GenLegal: for adding captures, deleting them, and finding a recapture
2414 extern void AtacksCallback P((Board board, int flags, ChessMove kind,
2415 int rf, int ff, int rt, int ft,
2419 AttacksCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
2420 { // For adding captures that can lead to chase indictment to the chaseStack
2421 if(board[rt][ft] == EmptySquare) return; // non-capture
2422 if(board[rt][ft] == WhitePawn && rt < BOARD_HEIGHT/2) return; // Pawn before river can be chased
2423 if(board[rt][ft] == BlackPawn && rt >= BOARD_HEIGHT/2) return; // Pawn before river can be chased
2424 if(board[rf][ff] == WhitePawn || board[rf][ff] == BlackPawn) return; // Pawns are allowed to chase
2425 if(board[rf][ff] == WhiteWazir || board[rf][ff] == BlackWazir) return; // King is allowed to chase
2426 // move cannot be excluded from being a chase trivially (based on attacker and victim); save it on chaseStack
2427 chaseStack[chaseStackPointer].rf = rf;
2428 chaseStack[chaseStackPointer].ff = ff;
2429 chaseStack[chaseStackPointer].rt = rt;
2430 chaseStack[chaseStackPointer].ft = ft;
2431 chaseStackPointer++;
2434 extern void ExistingAtacksCallback P((Board board, int flags, ChessMove kind,
2435 int rf, int ff, int rt, int ft,
2439 ExistingAttacksCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
2440 { // for removing pre-exsting captures from the chaseStack, to be left with newly created ones
2442 register ChaseClosure *cl = (ChaseClosure *) closure; //closure tells us the move played in the repeat loop
2444 if(board[rt][ft] == EmptySquare) return; // no capture
2445 if(rf == cl->rf && ff == cl->ff) { // attacks with same piece from new position are not considered new
2446 rf = cl->rt; ff = cl->ft; // doctor their fromSquare so they will be recognized in chaseStack
2448 // search move in chaseStack, and delete it if it occurred there (as we know now it is not a new capture)
2449 for(i=0; i<chaseStackPointer; i++) {
2450 if(chaseStack[i].rf == rf && chaseStack[i].ff == ff &&
2451 chaseStack[i].rt == rt && chaseStack[i].ft == ft ) {
2452 // move found on chaseStack, delete it by overwriting with move popped from top of chaseStack
2453 chaseStack[i] = chaseStack[--chaseStackPointer];
2459 extern void ProtectedCallback P((Board board, int flags, ChessMove kind,
2460 int rf, int ff, int rt, int ft,
2464 ProtectedCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
2465 { // for determining if a piece (given through the closure) is protected
2466 register ChaseClosure *cl = (ChaseClosure *) closure; // closure tells us where to recapture
2468 if(rt == cl->rt && ft == cl->ft) cl->recaptures++; // count legal recaptures to this square
2469 if(appData.debugMode && board[rt][ft] != EmptySquare)
2470 fprintf(debugFP, "try %c%c%c%c=%d\n", ff+AAA, rf+ONE,ft+AAA, rt+ONE, cl->recaptures);
2473 extern char moveList[MAX_MOVES][MOVE_LEN];
2476 PerpetualChase (int first, int last)
2477 { // this routine detects if the side to move in the 'first' position is perpetually chasing (when not checking)
2480 ChessSquare captured;
2482 preyStackPointer = 0; // clear stack of chased pieces
2483 for(i=first; i<last; i+=2) { // for all positions with same side to move
2484 if(appData.debugMode) fprintf(debugFP, "judge position %i\n", i);
2485 chaseStackPointer = 0; // clear stack that is going to hold possible chases
2486 // determine all captures possible after the move, and put them on chaseStack
2487 GenLegal(boards[i+1], PosFlags(i), AttacksCallback, &cl, EmptySquare);
2488 if(appData.debugMode) { int n;
2489 for(n=0; n<chaseStackPointer; n++)
2490 fprintf(debugFP, "%c%c%c%c ", chaseStack[n].ff+AAA, chaseStack[n].rf+ONE,
2491 chaseStack[n].ft+AAA, chaseStack[n].rt+ONE);
2492 fprintf(debugFP, ": all capts\n");
2494 // determine all captures possible before the move, and delete them from chaseStack
2495 cl.rf = moveList[i][1]-ONE; // prepare closure to pass move that led from i to i+1
2496 cl.ff = moveList[i][0]-AAA+BOARD_LEFT;
2497 cl.rt = moveList[i][3]-ONE;
2498 cl.ft = moveList[i][2]-AAA+BOARD_LEFT;
2499 CopyBoard(xqCheckers, nullBoard); xqCheckers[EP_STATUS] = 1; // giant kludge to make GenLegal ignore pre-existing checks
2500 GenLegal(boards[i], PosFlags(i), ExistingAttacksCallback, &cl, EmptySquare);
2501 xqCheckers[EP_STATUS] = 0; // disable the generation of quasi-legal moves again
2502 if(appData.debugMode) { int n;
2503 for(n=0; n<chaseStackPointer; n++)
2504 fprintf(debugFP, "%c%c%c%c ", chaseStack[n].ff+AAA, chaseStack[n].rf+ONE,
2505 chaseStack[n].ft+AAA, chaseStack[n].rt+ONE);
2506 fprintf(debugFP, ": new capts after %c%c%c%c\n", cl.ff+AAA, cl.rf+ONE, cl.ft+AAA, cl.rt+ONE);
2508 // chaseSack now contains all captures made possible by the move
2509 for(j=0; j<chaseStackPointer; j++) { // run through chaseStack to identify true chases
2510 int attacker = (int)boards[i+1][chaseStack[j].rf][chaseStack[j].ff];
2511 int victim = (int)boards[i+1][chaseStack[j].rt][chaseStack[j].ft];
2513 if(attacker >= (int) BlackPawn) attacker = BLACK_TO_WHITE attacker; // convert to white, as piecee type
2514 if(victim >= (int) BlackPawn) victim = BLACK_TO_WHITE victim;
2516 if((attacker == WhiteKnight || attacker == WhiteCannon) && victim == WhiteRook)
2517 continue; // C or H attack on R is always chase; leave on chaseStack
2519 if(attacker == victim) {
2520 if(LegalityTest(boards[i+1], PosFlags(i+1), chaseStack[j].rt,
2521 chaseStack[j].ft, chaseStack[j].rf, chaseStack[j].ff, NULLCHAR) == NormalMove) {
2522 // we can capture back with equal piece, so this is no chase but a sacrifice
2523 chaseStack[j] = chaseStack[--chaseStackPointer]; // delete the capture from the chaseStack
2524 j--; /* ! */ continue;
2529 // the attack is on a lower piece, or on a pinned or blocked equal one
2530 CopyBoard(xqCheckers, nullBoard); xqCheckers[EP_STATUS] = 1;
2531 CheckTest(boards[i+1], PosFlags(i+1), -1, -1, -1, -1, FALSE); // if we deliver check with our move, the checkers get marked
2532 // test if the victim is protected by a true protector. First make the capture.
2533 captured = boards[i+1][chaseStack[j].rt][chaseStack[j].ft];
2534 boards[i+1][chaseStack[j].rt][chaseStack[j].ft] = boards[i+1][chaseStack[j].rf][chaseStack[j].ff];
2535 boards[i+1][chaseStack[j].rf][chaseStack[j].ff] = EmptySquare;
2536 // Then test if the opponent can recapture
2537 cl.recaptures = 0; // prepare closure to pass recapture square and count moves to it
2538 cl.rt = chaseStack[j].rt;
2539 cl.ft = chaseStack[j].ft;
2540 if(appData.debugMode) {
2541 fprintf(debugFP, "test if we can recapture %c%c\n", cl.ft+AAA, cl.rt+ONE);
2543 xqCheckers[EP_STATUS] = 2; // causes GenLegal to ignore the checks we delivered with the move, in real life evaded before we captured
2544 GenLegal(boards[i+1], PosFlags(i+1), ProtectedCallback, &cl, EmptySquare); // try all moves
2545 xqCheckers[EP_STATUS] = 0; // disable quasi-legal moves again
2546 // unmake the capture
2547 boards[i+1][chaseStack[j].rf][chaseStack[j].ff] = boards[i+1][chaseStack[j].rt][chaseStack[j].ft];
2548 boards[i+1][chaseStack[j].rt][chaseStack[j].ft] = captured;
2549 // if a recapture was found, piece is protected, and we are not chasing it.
2550 if(cl.recaptures) { // attacked piece was defended by true protector, no chase
2551 chaseStack[j] = chaseStack[--chaseStackPointer]; // so delete from chaseStack
2555 // chaseStack now contains all moves that chased
2556 if(appData.debugMode) { int n;
2557 for(n=0; n<chaseStackPointer; n++)
2558 fprintf(debugFP, "%c%c%c%c ", chaseStack[n].ff+AAA, chaseStack[n].rf+ONE,
2559 chaseStack[n].ft+AAA, chaseStack[n].rt+ONE);
2560 fprintf(debugFP, ": chases\n");
2562 if(i == first) { // copy all people chased by first move of repeat cycle to preyStack
2563 for(j=0; j<chaseStackPointer; j++) {
2564 preyStack[j].rank = chaseStack[j].rt;
2565 preyStack[j].file = chaseStack[j].ft;
2567 preyStackPointer = chaseStackPointer;
2570 for(j=0; j<chaseStackPointer; j++) {
2571 for(k=0; k<preyStackPointer; k++) {
2572 // search the victim of each chase move on the preyStack (first occurrence)
2573 if(chaseStack[j].ft == preyStack[k].file && chaseStack[j].rt == preyStack[k].rank ) {
2574 if(k < tail) break; // piece was already identified as still being chased
2575 preyStack[preyStackPointer] = preyStack[tail]; // move chased piece to bottom part of preyStack
2576 preyStack[tail] = preyStack[k]; // by swapping
2577 preyStack[k] = preyStack[preyStackPointer];
2583 preyStackPointer = tail; // keep bottom part of preyStack, popping pieces unchased on move i.
2584 if(appData.debugMode) { int n;
2585 for(n=0; n<preyStackPointer; n++)
2586 fprintf(debugFP, "%c%c ", preyStack[n].file+AAA, preyStack[n].rank+ONE);
2587 fprintf(debugFP, "always chased upto ply %d\n", i);
2589 // now adjust the location of the chased pieces according to opponent move
2590 for(j=0; j<preyStackPointer; j++) {
2591 if(preyStack[j].rank == moveList[i+1][1]-ONE &&
2592 preyStack[j].file == moveList[i+1][0]-AAA+BOARD_LEFT) {
2593 preyStack[j].rank = moveList[i+1][3]-ONE;
2594 preyStack[j].file = moveList[i+1][2]-AAA+BOARD_LEFT;
2599 return preyStackPointer ? 256*(preyStack[preyStackPointer].file - BOARD_LEFT + AAA) + (preyStack[preyStackPointer].rank + ONE)
2600 : 0; // if any piece was left on preyStack, it has been perpetually chased,and we return the