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, 2015, 2016 Free
9 * Software Foundation, Inc.
11 * Enhancements Copyright 2005 Alessandro Scotti
13 * The following terms apply to Digital Equipment Corporation's copyright
15 * ------------------------------------------------------------------------
18 * Permission to use, copy, modify, and distribute this software and its
19 * documentation for any purpose and without fee is hereby granted,
20 * provided that the above copyright notice appear in all copies and that
21 * both that copyright notice and this permission notice appear in
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23 * used in advertising or publicity pertaining to distribution of the
24 * software without specific, written prior permission.
26 * DIGITAL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING
27 * ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL
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29 * ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
30 * WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
31 * ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
33 * ------------------------------------------------------------------------
35 * The following terms apply to the enhanced version of XBoard
36 * distributed by the Free Software Foundation:
37 * ------------------------------------------------------------------------
39 * GNU XBoard is free software: you can redistribute it and/or modify
40 * it under the terms of the GNU General Public License as published by
41 * the Free Software Foundation, either version 3 of the License, or (at
42 * your option) any later version.
44 * GNU XBoard is distributed in the hope that it will be useful, but
45 * WITHOUT ANY WARRANTY; without even the implied warranty of
46 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
47 * General Public License for more details.
49 * You should have received a copy of the GNU General Public License
50 * along with this program. If not, see http://www.gnu.org/licenses/. *
52 *------------------------------------------------------------------------
53 ** See the file ChangeLog for a revision history. */
62 #else /* not HAVE_STRING_H */
64 #endif /* not HAVE_STRING_H */
70 int WhitePiece P((ChessSquare));
71 int BlackPiece P((ChessSquare));
72 int SameColor P((ChessSquare, ChessSquare));
73 int PosFlags(int index);
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 unsigned char pieceToChar[EmptySquare+1] = {
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 unsigned char pieceNickName[EmptySquare];
124 int promoPartner[EmptySquare];
127 PieceToChar (ChessSquare p)
130 if((int)p < 0 || (int)p >= (int)EmptySquare) return('?'); /* [HGM] for safety */
131 c = pieceToChar[(int) p];
132 if(c & 128) c = c & 63 | 64;
137 PieceSuffix (ChessSquare p)
140 if((int)p < 0 || (int)p >= (int)EmptySquare) return 0; /* [HGM] for safety */
141 c = pieceToChar[(int) p];
142 if(c < 128) return 0;
143 return SUFFIXES[c - 128 >> 6];
147 PieceToNumber (ChessSquare p) /* [HGM] holdings: count piece type, ignoring non-participating piece types */
150 ChessSquare start = (int)p >= (int)BlackPawn ? BlackPawn : WhitePawn;
152 while(start++ != p) if(pieceToChar[start-1] != '.' && pieceToChar[start-1] != '+') i++;
160 if(c == '.') return EmptySquare;
161 for(i=0; i< (int) EmptySquare; i++)
162 if(pieceNickName[i] == c) return (ChessSquare) i;
163 for(i=0; i< (int) EmptySquare; i++)
164 if(pieceToChar[i] == c) return (ChessSquare) i;
169 CopyBoard (Board to, Board from)
173 for (i = 0; i < BOARD_HEIGHT; i++)
174 for (j = 0; j < BOARD_WIDTH; j++)
175 to[i][j] = from[i][j];
176 for (j = 0; j < BOARD_FILES; j++) // [HGM] gamestate: copy castling rights and ep status
177 to[VIRGIN][j] = from[VIRGIN][j],
178 to[CASTLING][j] = from[CASTLING][j];
179 to[HOLDINGS_SET] = 0; // flag used in ICS play
183 CompareBoards (Board board1, Board board2)
187 for (i = 0; i < BOARD_HEIGHT; i++)
188 for (j = 0; j < BOARD_WIDTH; j++) {
189 if (board1[i][j] != board2[i][j])
195 char defaultName[] = "PNBRQ......................................K" // white
196 "pnbrq......................................k"; // black
197 char shogiName[] = "PNBRLS...G.++++++..........................K" // white
198 "pnbrls...g.++++++..........................k"; // black
199 char xqName[] = "PH.R.AE..K.C................................" // white
200 "ph.r.ae..k.c................................"; // black
203 CollectPieceDescriptors ()
204 { // make a line of piece descriptions for use in the PGN Piece tag:
205 // dump all engine defined pieces, and pieces with non-standard names,
206 // but suppress black pieces that are the same as their white counterpart
208 static char buf[MSG_SIZ], s[2];
209 char *m, *pieceName = defaultName;
212 if(!pieceDefs) return "";
213 if(gameInfo.variant == VariantChu) return ""; // for now don't do this for Chu Shogi
214 if(gameInfo.variant == VariantShogi) pieceName = shogiName;
215 if(gameInfo.variant == VariantXiangqi) pieceName = xqName;
216 for(p=WhitePawn; p<EmptySquare; p++) {
217 if((c = pieceToChar[p]) == '.' || c == '~') continue; // does not participate
218 m = pieceDesc[p]; d = (c == '+' ? pieceToChar[DEMOTED(p)] : c);
219 if(p >= BlackPawn && pieceToChar[BLACK_TO_WHITE p] == (c & ~32)
220 && (c != '+' || pieceToChar[DEMOTED(BLACK_TO_WHITE p)] == d)) {// black member of normal pair
221 char *wm = pieceDesc[BLACK_TO_WHITE p];
222 if(!m && !wm || m && wm && !strcmp(wm, m)) continue; // moves as a white piece
223 } else // white or unpaired black
224 if((p < BlackPawn || CharToPiece(d & ~32) != EmptySquare) && // white or lone black
225 !pieceDesc[p] /*&& pieceName[p] == c*/) continue; // orthodox piece known by its usual name
226 // TODO: listing pieces because of unusual name can only be done if we have accurate Betza of all defaults
227 if(!m) m = defaultDesc[p];
230 *s = (d > 128 ? SUFFIXES[d-128>>6] : 0); d = 64 + (d & 63);
231 snprintf(buf+len, MSG_SIZ-len, "%s%s%c%s:%s", len ? ";" : "", c == '+' ? "+" : "", d, s, m);
237 LoadPieceDesc (char *s)
240 static char suf[] = SUFFIXES;
242 int ok = TRUE, promoted, c;
244 printf("pstring = %s\n", s);
247 if(q) *q = 0, s = q+1;
248 if(*p == '+') promoted = 1, p++; else promoted = 0;
250 if(!c) { ok = FALSE; continue; } // bad syntax
251 if(*p && (r = strchr(suf, *p))) c += 64*(r - suf + 1), p++;
252 if(*p++ != ':') { ok = FALSE; continue; } // bad syntax
253 if(!strcmp(p, "(null)")) continue; // handle bug in writing of XBoard 4.8.0
254 piece = CharToPiece(c);
255 if(piece >= EmptySquare) { ok = FALSE; continue; } // non-existent piece
257 piece = promoPartner[piece];
258 if(pieceToChar[piece] != '+') { ok = FALSE; continue; } // promoted form does not exist
260 ASSIGN(pieceDesc[piece], p);
261 if(piece < BlackPawn && (pieceToChar[WHITE_TO_BLACK piece] == pieceToChar[piece] + 32 || promoted)) {
262 ASSIGN(pieceDesc[WHITE_TO_BLACK piece], p);
270 // [HGM] gen: configurable move generation from Betza notation sent by engine.
271 // Some notes about two-leg moves: GenPseudoLegal() works in two modes, depending on whether a 'kill-
272 // square has been set: without one is generates all moves, and a global int legNr flags in bits 0 and 1
273 // if the move has 1 or 2 legs. Only the marking of squares makes use of this info, by only marking
274 // target squares of leg 1 (rejecting null move). A dummy move with MoveType 'FirstLeg' to the relay square
275 // is generated, so a cyan marker can be put there, and other functions can ignore such a move. When the
276 // user selects this square, it becomes the kill-square. Once a kill-square is set, only 2-leg moves are
277 // generated that use that square as relay, plus 1-leg moves, so the 1-leg move that goes to the kill-square
278 // can be marked during 2nd-leg entry to terminate the move there. For judging the pseudo-legality of the
279 // 2nd leg, the from-square has to be considered empty, although the moving piece is still on it.
283 // alphabet "abcdefghijklmnopqrstuvwxyz"
284 char symmetry[] = "FBNW.FFW.NKN.NW.QR....W..N";
285 char xStep[] = "2110.130.102.10.00....0..2";
286 char yStep[] = "2132.133.313.20.11....1..3";
287 char dirType[] = "01000104000200000260050000";
288 char upgrade[] = "AFCD.BGH.JQL.NO.KW....R..Z";
289 char rotate[] = "DRCA.WHG.JKL.NO.QB....F..Z";
291 // 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 "
292 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 };
293 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 };
294 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 };
295 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 };
297 int rot[][4] = { // rotation matrices for each direction
309 OK (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR cl)
315 MovesFromString (Board board, int flags, int f, int r, int tx, int ty, int angle, int range, char *desc, MoveCallback cb, VOIDSTAR cl)
317 char buf[80], *p = desc, *atom = NULL;
318 int mine, his, dir, bit, occup, i, ep, promoRank = -1;
319 ChessMove promo= NormalMove; ChessSquare pc = board[r][f];
320 if(pc == DarkSquare) return; // this is not a piece, but a 'hole' in the board
321 if(flags & F_WHITE_ON_MOVE) his = 2, mine = 1; else his = 1, mine = 2;
322 if(pc == WhitePawn || pc == WhiteLance) promo = WhitePromotion, promoRank = BOARD_HEIGHT-1; else
323 if(pc == BlackPawn || pc == BlackLance) promo = BlackPromotion, promoRank = 0;
324 while(*p) { // more moves to go
325 int expo = -1, dx, dy, x, y, mode, dirSet, ds2=0, retry=0, initial=0, jump=1, skip = 0, all = 0;
327 while(*p == 'i') initial++, desc = ++p;
328 while(islower(*p)) p++; // skip prefixes
329 if(!isupper(*p)) return; // syntax error: no atom
330 dx = xStep[*p-'A'] - '0';// step vector of atom
331 dy = yStep[*p-'A'] - '0';
332 dirSet = 0; // build direction set based on atom symmetry
333 switch(symmetry[*p-'A']) {
334 case 'B': expo = 0; // bishop, slide
335 case 'F': all = 0xAA; // diagonal atom (degenerate 4-fold)
336 if(tx >= 0) goto king; // continuation legs specified in K/Q system!
337 while(islower(*desc) && (i = dirType[*desc-'a']) != '0') {
338 int b = dirs1[*desc-'a']; // use wide version
339 if( islower(desc[1]) &&
340 ((i | dirType[desc[1]-'a']) & 3) == 3) { // combinable (perpendicular dim)
341 b = dirs1[*desc-'a'] & dirs1[desc[1]-'a']; // intersect wide & perp wide
346 dirSet &= 0xAA; if(!dirSet) dirSet = 0xAA;
348 case 'R': expo = 0; // rook, slide
349 case 'W': all = 0x55; // orthogonal atom (non-deg 4-fold)
350 if(tx >= 0) goto king; // continuation legs specified in K/Q system!
351 while(islower(*desc) && (dirType[*desc-'a'] & ~4) != '0') dirSet |= dirs2[*desc++-'a'];
352 dirSet &= 0x55; if(!dirSet) dirSet = 0x55;
353 dirSet = (dirSet << angle | dirSet >> 8-angle) & 255; // re-orient direction system
355 case 'N': all = 0xFF; // oblique atom (degenerate 8-fold)
356 if(tx >= 0) goto king; // continuation legs specified in K/Q system!
357 if(*desc == 'h') { // chiral direction sets 'hr' and 'hl'
358 dirSet = (desc[1] == 'r' ? 0x55 : 0xAA); desc += 2;
360 while(islower(*desc) && (i = dirType[*desc-'a']) != '0') {
361 int b = dirs2[*desc-'a']; // when alone, use narrow version
362 if(desc[1] == 'h') b = dirs1[*desc-'a'], desc += 2; // dirs1 is wide version
363 else if(*desc == desc[1] || islower(desc[1]) && i < '4'
364 && ((i | dirType[desc[1]-'a']) & 3) == 3) { // combinable (perpendicular dim or same)
365 b = dirs1[*desc-'a'] & dirs2[desc[1]-'a']; // intersect wide & perp narrow
370 if(!dirSet) dirSet = 0xFF;
372 case 'Q': expo = 0; // queen, slide
373 case 'K': all = 0xFF; // non-deg (pseudo) 8-fold
375 while(islower(*desc) && (i = dirType[*desc-'a']) != '0') {
376 int b = dirs4[*desc-'a']; // when alone, use narrow version
377 if(desc[1] == *desc) desc++; // doubling forces alone
378 else if(islower(desc[1]) && i < '4'
379 && ((i | dirType[desc[1]-'a']) & 3) == 3) { // combinable (perpendicular dim or same)
380 b = dirs3[*desc-'a'] & dirs3[desc[1]-'a']; // intersect wide & perp wide
385 if(!dirSet) dirSet = (tx < 0 ? 0xFF // default is all directions, but in continuation leg
386 : all == 0xFF ? 0xEF : 0x45); // omits backward, and for 4-fold atoms also diags
387 dirSet = (dirSet << angle | dirSet >> 8-angle) & 255; // re-orient direction system
388 ds2 = dirSet & 0xAA; // extract diagonal directions
389 if(dirSet &= 0x55) // start with orthogonal moves, if present
390 retry = 1, dx = 0; // and schedule the diagonal moves for later
391 else dx = dy, dirSet = ds2; // if no orthogonal directions, do diagonal immediately
392 break; // should not have direction indicators
393 default: return; // syntax error: invalid atom
395 if(mine == 2 && tx < 0) dirSet = dirSet >> 4 | dirSet << 4 & 255; // invert black moves
396 mode = 0; // build mode mask
397 if(*desc == 'm') mode |= 4, desc++; // move to empty
398 if(*desc == 'c') mode |= his, desc++; // capture foe
399 if(*desc == 'd') mode |= mine, desc++; // destroy (capture friend)
400 if(*desc == 'e') mode |= 8, desc++; // e.p. capture last mover
401 if(*desc == 't') mode |= 16, desc++; // exclude enemies as hop platform ('test')
402 if(*desc == 'p') mode |= 32, desc++; // hop over occupied
403 if(*desc == 'g') mode |= 64, desc++; // hop and toggle range
404 if(*desc == 'o') mode |= 128, desc++; // wrap around cylinder board
405 if(*desc == 'y') mode |= 512, desc++; // toggle range on empty square
406 if(*desc == 'n') jump = 0, desc++; // non-jumping
407 while(*desc == 'j') jump++, desc++; // must jump (on B,R,Q: skip first square)
408 if(*desc == 'a') cont = ++desc; // move again after doing what preceded it
409 if(isdigit(*++p)) expo = atoi(p++); // read exponent
410 if(expo > 9) p++; // allow double-digit
411 desc = p; // this is start of next move
412 if(initial == 2) { if(board[r][f] != initialPosition[r-2*his+3][f]) continue; initial = 0; } else
413 if(initial && !range) {
414 if( (board[r][f] != initialPosition[r][f] ||
415 r == 0 && board[TOUCHED_W] & 1<<f ||
416 r == BOARD_HEIGHT-1 && board[TOUCHED_B] & 1<<f )) continue;
419 if(expo > 0 && dx == 0 && dy == 0) { // castling indicated by O + number
420 mode |= 1024; dy = 1;
422 if(expo < 0) expo = 1; // use 1 for default
424 if(!(mode & 15)) mode |= his + 4; // no mode spec, use default = mc
426 strncpy(buf, cont, 80); cont = buf; // copy next leg(s), so we can modify
427 atom = buf; while(islower(*atom)) atom++; // skip to atom
428 if(mode & 32) mode ^= 256 + 32; // in non-final legs 'p' means 'pass through'
429 if(mode & 64 + 512) {
430 mode |= 256; // and 'g' too, but converts leaper <-> slider
431 if(mode & 512) mode ^= 0x304; // and 'y' is m-like 'g'
432 *atom = upgrade[*atom-'A']; // replace atom, BRQ <-> FWK
433 atom[1] = atom[2] = '\0'; // make sure any old range is stripped off
434 if(expo == 1) atom[1] = '0'; // turn other leapers into riders
436 if(!(mode & 0x30F)) mode |= 4; // and default of this leg = m
438 if(dy == 1) skip = jump - 1, jump = 1; // on W & F atoms 'j' = skip first square
440 for(dir=0, bit=1; dir<8; dir++, bit += bit) { // loop over directions
441 int i = expo, j = skip, hop = mode, vx, vy, loop = 0;
442 if(!(bit & dirSet)) continue; // does not move in this direction
443 if(dy != 1 || mode & 1024) j = 0; //
444 vx = dx*rot[dir][0] + dy*rot[dir][1]; // rotate step vector
445 vy = dx*rot[dir][2] + dy*rot[dir][3];
446 if(tx < 0) x = f, y = r; // start square
447 else x = tx, y = ty; // from previous to-square if continuation
449 x += vx; y += vy; // step to next square
450 if(y < 0 || y >= BOARD_HEIGHT) break; // vertically off-board: always done
451 if(x < BOARD_LEFT) { if(mode & 128) x += BOARD_RGHT - BOARD_LEFT, loop++; else break; }
452 if(x >= BOARD_RGHT) { if(mode & 128) x -= BOARD_RGHT - BOARD_LEFT, loop++; else break; }
453 if(j) { j--; continue; } // skip irrespective of occupation
454 if(board[y][x] == DarkSquare) break; // black squares are supposed to be off board
455 if(!jump && board[y - vy + vy/2][x - vx + vx/2] != EmptySquare) break; // blocked
456 if(jump > 1 && board[y - vy + vy/2][x - vx + vx/2] == EmptySquare) break; // no hop
457 if(x == f && y == r && !loop) occup = 4; else // start square counts as empty (if not around cylinder!)
458 if(board[y][x] < BlackPawn) occup = 0x101; else
459 if(board[y][x] < EmptySquare) occup = 0x102; else
461 if(initial && expo - i + 1 != range) { if(occup == 4) continue; else break; }
462 if(cont) { // non-final leg
463 if(mode&16 && his&occup) occup &= 3;// suppress hopping foe in t-mode
464 if(occup & mode) { // valid intermediate square, do continuation
465 char origAtom = *atom;
466 int rg = (expo != 1 ? expo - i + 1 : range); // pass length of last *slider* leg
467 if(!(bit & all)) *atom = rotate[*atom - 'A']; // orth-diag interconversion to make direction valid
468 if(occup & mode & 0x104) // no side effects, merge legs to one move
469 MovesFromString(board, flags, f, r, x, y, dir, rg, cont, cb, cl);
470 if(occup & mode & 3 && (killX < 0 || kill2X < 0 && (legNr > 1 || killX == x && killY == y) ||
471 (legNr == 1 ? kill2X == x && kill2Y == y : killX == x && killY == y))) { // destructive first leg
474 MovesFromString(board, flags, f, r, x, y, dir, rg, cont, &OK, &cnt); // count possible continuations
476 if(cnt) { // and if there are
477 if(legNr & 1 ? killX < 0 : kill2X < 0) cb(board, flags, FirstLeg, r, f, y, x, cl); // then generate their first leg
479 MovesFromString(board, flags, f, r, x, y, dir, rg, cont, cb, cl);
483 *atom = origAtom; // undo any interconversion
485 if(occup != 4) break; // occupied squares always terminate the leg
488 if(hop & 32+64) { if(occup != 4) { if(hop & 64 && i != 1) i = 2; hop &= 31; } continue; } // hopper
490 if(mode & 8 && occup == 4 && board[EP_FILE] == x && (y == (ep & 127) || y - vy == ep - 128)) { // to e.p. square (or 2nd e.p. square)
491 cb(board, flags, mine == 1 ? WhiteCapturesEnPassant : BlackCapturesEnPassant, r, f, y, x, cl);
493 if(mode & 1024) { // castling
494 i = 2; // kludge to elongate move indefinitely
495 if(occup == 4) continue; // skip empty squares
496 if((x == BOARD_LEFT + skip || x > BOARD_LEFT + skip && vx < 0 && board[y][x-1-skip] == DarkSquare)
497 && board[y][x] == initialPosition[y][x]) { // reached initial corner piece
498 if(pc != WhiteKing && pc != BlackKing || expo == 1) { // non-royal castling (to be entered as two-leg move via 'Rook')
499 if(killX < 0) cb(board, flags, FirstLeg, r, f, y, x, cl); if(killX < f)
500 legNr <<= 1, cb(board, flags, NormalMove, r, f, y, f - expo, cl), legNr >>= 1;
502 cb(board, flags, mine == 1 ? WhiteQueenSideCastle : BlackQueenSideCastle, r, f, y, f - expo, cl);
504 if((x == BOARD_RGHT-1-skip || x < BOARD_RGHT-1-skip && vx > 0 && board[y][x+1+skip] == DarkSquare)
505 && board[y][x] == initialPosition[y][x]) {
506 if(pc != WhiteKing && pc != BlackKing || expo == 1) {
507 if(killX < 0) cb(board, flags, FirstLeg, r, f, y, x, cl); if(killX > f)
508 legNr <<= 1, cb(board, flags, NormalMove, r, f, y, f + expo, cl), legNr >>= 1;
510 cb(board, flags, mine == 1 ? WhiteKingSideCastle : BlackKingSideCastle, r, f, y, f + expo, cl);
514 if(mode & 16 && (board[y][x] == WhiteKing || board[y][x] == BlackKing)) break; // tame piece, cannot capture royal
515 if(occup & mode) cb(board, flags, y == promoRank ? promo : NormalMove, r, f, y, x, cl); // allowed, generate
516 if(occup != 4) break; // not valid transit square
519 dx = dy; dirSet = ds2; // prepare for diagonal moves of K,Q
520 } while(retry-- && ds2); // and start doing them
521 if(tx >= 0) break; // don't do other atoms in continuation legs
525 // [HGM] move generation now based on hierarchy of subroutines for rays and combinations of rays
528 SlideForward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
533 if (rt >= BOARD_HEIGHT) break;
534 if (SameColor(board[rf][ff], board[rt][ft])) break;
535 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
536 if (board[rt][ft] != EmptySquare) break;
541 SlideBackward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
547 if (SameColor(board[rf][ff], board[rt][ft])) break;
548 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
549 if (board[rt][ft] != EmptySquare) break;
554 SlideVertical (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
556 SlideForward(board, flags, rf, ff, callback, closure);
557 SlideBackward(board, flags, rf, ff, callback, closure);
561 SlideSideways (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
563 int i, s, rt = rf, ft;
564 for(s = -1; s <= 1; s+= 2) {
567 if (ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
568 if (SameColor(board[rf][ff], board[rt][ft])) break;
569 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
570 if (board[rt][ft] != EmptySquare) break;
576 SlideDiagForward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
579 for(s = -1; s <= 1; s+= 2) {
583 if (rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
584 if (SameColor(board[rf][ff], board[rt][ft])) break;
585 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
586 if (board[rt][ft] != EmptySquare) break;
592 SlideDiagBackward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
595 for(s = -1; s <= 1; s+= 2) {
599 if (rt < 0 || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
600 if (SameColor(board[rf][ff], board[rt][ft])) break;
601 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
602 if (board[rt][ft] != EmptySquare) break;
608 Rook (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
610 SlideVertical(board, flags, rf, ff, callback, closure);
611 SlideSideways(board, flags, rf, ff, callback, closure);
615 Bishop (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
617 SlideDiagForward(board, flags, rf, ff, callback, closure);
618 SlideDiagBackward(board, flags, rf, ff, callback, closure);
622 Sting (Board board, int flags, int rf, int ff, int dy, int dx, MoveCallback callback, VOIDSTAR closure)
623 { // Lion-like move of Horned Falcon and Soaring Eagle
624 int ft = ff + dx, rt = rf + dy;
625 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) return;
627 if (!SameColor(board[rf][ff], board[rt][ft]))
628 callback(board, flags, killX < 0 && board[rt][ft] != EmptySquare ? FirstLeg : NormalMove, rf, ff, rt, ft, closure);
631 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) return;
633 if (!SameColor(board[rf][ff], board[rt][ft]))
634 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
635 if (!SameColor(board[rf][ff], board[rf+dy][ff+dx]))
636 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
641 StepForward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
643 int ft = ff, rt = rf + 1;
644 if (rt >= BOARD_HEIGHT) return;
645 if (SameColor(board[rf][ff], board[rt][ft])) return;
646 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
650 StepBackward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
652 int ft = ff, rt = rf - 1;
654 if (SameColor(board[rf][ff], board[rt][ft])) return;
655 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
659 StepSideways (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
663 if (!(rt >= BOARD_HEIGHT || ft >= BOARD_RGHT) && !SameColor(board[rf][ff], board[rt][ft]))
664 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
666 if (!(rt >= BOARD_HEIGHT || ft < BOARD_LEFT) && !SameColor(board[rf][ff], board[rt][ft]))
667 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
671 StepDiagForward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
674 if (rt >= BOARD_HEIGHT) return;
676 if (!(rt >= BOARD_HEIGHT || ft >= BOARD_RGHT) && !SameColor(board[rf][ff], board[rt][ft]))
677 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
679 if (!(rt >= BOARD_HEIGHT || ft < BOARD_LEFT) && !SameColor(board[rf][ff], board[rt][ft]))
680 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
684 StepDiagBackward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
689 if (!(rt < 0 || ft >= BOARD_RGHT) && !SameColor(board[rf][ff], board[rt][ft]))
690 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
692 if (!(rt < 0 || ft < BOARD_LEFT) && !SameColor(board[rf][ff], board[rt][ft]))
693 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
697 StepVertical (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
699 StepForward(board, flags, rf, ff, callback, closure);
700 StepBackward(board, flags, rf, ff, callback, closure);
704 Ferz (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
706 StepDiagForward(board, flags, rf, ff, callback, closure);
707 StepDiagBackward(board, flags, rf, ff, callback, closure);
711 Wazir (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
713 StepVertical(board, flags, rf, ff, callback, closure);
714 StepSideways(board, flags, rf, ff, callback, closure);
718 Knight (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
721 for (i = -1; i <= 1; i += 2)
722 for (j = -1; j <= 1; j += 2)
723 for (s = 1; s <= 2; s++) {
726 if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
727 && ( gameInfo.variant != VariantXiangqi || board[rf+i*(s-1)][ff+j*(2-s)] == EmptySquare)
728 && !SameColor(board[rf][ff], board[rt][ft]))
729 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
733 /* Call callback once for each pseudo-legal move in the given
734 position, except castling moves. A move is pseudo-legal if it is
735 legal, or if it would be legal except that it leaves the king in
736 check. In the arguments, epfile is EP_NONE if the previous move
737 was not a double pawn push, or the file 0..7 if it was, or
738 EP_UNKNOWN if we don't know and want to allow all e.p. captures.
739 Promotion moves generated are to Queen only.
742 GenPseudoLegal (Board board, int flags, MoveCallback callback, VOIDSTAR closure, ChessSquare filter)
743 // speed: only do moves with this piece type
746 int i, j, d, s, fs, rs, rt, ft, m;
747 int epfile = (signed char)board[EP_STATUS]; // [HGM] gamestate: extract ep status from board
748 int promoRank = gameInfo.variant == VariantMakruk || gameInfo.variant == VariantGrand || gameInfo.variant == VariantChuChess ? 3 : 1;
750 for (rf = 0; rf < BOARD_HEIGHT; rf++)
751 for (ff = BOARD_LEFT; ff < BOARD_RGHT; ff++) {
754 if(board[rf][ff] == EmptySquare) continue;
755 if ((flags & F_WHITE_ON_MOVE) != (board[rf][ff] < BlackPawn)) continue; // [HGM] speed: wrong color
756 m = 0; piece = board[rf][ff];
757 if(PieceToChar(piece) == '~')
758 piece = (ChessSquare) ( DEMOTED(piece) );
759 if(filter != EmptySquare && piece != filter) continue;
760 if(pieceDefs && pieceDesc[piece]) { // [HGM] gen: use engine-defined moves
761 MovesFromString(board, flags, ff, rf, -1, -1, 0, 0, pieceDesc[piece], callback, closure);
764 if(IS_SHOGI(gameInfo.variant))
765 piece = (ChessSquare) ( SHOGI piece );
767 switch ((int)piece) {
768 /* case EmptySquare: [HGM] this is nonsense, and conflicts with Shogi cases */
770 /* can't happen ([HGM] except for faries...) */
774 if(gameInfo.variant == VariantXiangqi) {
775 /* [HGM] capture and move straight ahead in Xiangqi */
776 if (rf < BOARD_HEIGHT-1 &&
777 !SameColor(board[rf][ff], board[rf + 1][ff]) ) {
778 callback(board, flags, NormalMove,
779 rf, ff, rf + 1, ff, closure);
781 /* and move sideways when across the river */
782 for (s = -1; s <= 1; s += 2) {
783 if (rf >= BOARD_HEIGHT>>1 &&
784 ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
785 !WhitePiece(board[rf][ff+s]) ) {
786 callback(board, flags, NormalMove,
787 rf, ff, rf, ff+s, closure);
792 if (rf < BOARD_HEIGHT-1 && board[rf + 1][ff] == EmptySquare) {
793 callback(board, flags,
794 rf >= BOARD_HEIGHT-1-promoRank ? WhitePromotion : NormalMove,
795 rf, ff, rf + 1, ff, closure);
797 if (rf <= (BOARD_HEIGHT>>1)-3 && board[rf+1][ff] == EmptySquare && // [HGM] grand: also on 3rd rank on 10-board
798 gameInfo.variant != VariantShatranj && /* [HGM] */
799 gameInfo.variant != VariantCourier && /* [HGM] */
800 board[rf+2][ff] == EmptySquare ) {
801 callback(board, flags, NormalMove,
802 rf, ff, rf+2, ff, closure);
804 for (s = -1; s <= 1; s += 2) {
805 if (rf < BOARD_HEIGHT-1 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
806 ((flags & F_KRIEGSPIEL_CAPTURE) ||
807 BlackPiece(board[rf + 1][ff + s]))) {
808 callback(board, flags,
809 rf >= BOARD_HEIGHT-1-promoRank ? WhitePromotion : NormalMove,
810 rf, ff, rf + 1, ff + s, closure);
812 if (rf >= BOARD_HEIGHT+1>>1) {// [HGM] grand: 4th & 5th rank on 10-board
813 if (ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
814 (epfile == ff + s || epfile == EP_UNKNOWN) && rf < BOARD_HEIGHT-3 &&
815 board[rf][ff + s] == BlackPawn &&
816 board[rf+1][ff + s] == EmptySquare) {
817 callback(board, flags, WhiteCapturesEnPassant,
818 rf, ff, rf+1, ff + s, closure);
825 if(gameInfo.variant == VariantXiangqi) {
826 /* [HGM] capture straight ahead in Xiangqi */
827 if (rf > 0 && !SameColor(board[rf][ff], board[rf - 1][ff]) ) {
828 callback(board, flags, NormalMove,
829 rf, ff, rf - 1, ff, closure);
831 /* and move sideways when across the river */
832 for (s = -1; s <= 1; s += 2) {
833 if (rf < BOARD_HEIGHT>>1 &&
834 ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
835 !BlackPiece(board[rf][ff+s]) ) {
836 callback(board, flags, NormalMove,
837 rf, ff, rf, ff+s, closure);
842 if (rf > 0 && board[rf - 1][ff] == EmptySquare) {
843 callback(board, flags,
844 rf <= promoRank ? BlackPromotion : NormalMove,
845 rf, ff, rf - 1, ff, closure);
847 if (rf >= (BOARD_HEIGHT+1>>1)+2 && board[rf-1][ff] == EmptySquare && // [HGM] grand
848 gameInfo.variant != VariantShatranj && /* [HGM] */
849 gameInfo.variant != VariantCourier && /* [HGM] */
850 board[rf-2][ff] == EmptySquare) {
851 callback(board, flags, NormalMove,
852 rf, ff, rf-2, ff, closure);
854 for (s = -1; s <= 1; s += 2) {
855 if (rf > 0 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
856 ((flags & F_KRIEGSPIEL_CAPTURE) ||
857 WhitePiece(board[rf - 1][ff + s]))) {
858 callback(board, flags,
859 rf <= promoRank ? BlackPromotion : NormalMove,
860 rf, ff, rf - 1, ff + s, closure);
862 if (rf < BOARD_HEIGHT>>1) {
863 if (ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
864 (epfile == ff + s || epfile == EP_UNKNOWN) && rf > 2 &&
865 board[rf][ff + s] == WhitePawn &&
866 board[rf-1][ff + s] == EmptySquare) {
867 callback(board, flags, BlackCapturesEnPassant,
868 rf, ff, rf-1, ff + s, closure);
878 for (i = -1; i <= 1; i += 2)
879 for (j = -1; j <= 1; j += 2)
880 for (s = 1; s <= 2; s++) {
883 if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
884 && ( gameInfo.variant != VariantXiangqi || board[rf+i*(s-1)][ff+j*(2-s)] == EmptySquare)
885 && !SameColor(board[rf][ff], board[rt][ft]))
886 callback(board, flags, NormalMove,
887 rf, ff, rt, ft, closure);
891 case SHOGI WhiteKnight:
892 for (s = -1; s <= 1; s += 2) {
893 if (rf < BOARD_HEIGHT-2 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
894 !SameColor(board[rf][ff], board[rf + 2][ff + s])) {
895 callback(board, flags, NormalMove,
896 rf, ff, rf + 2, ff + s, closure);
901 case SHOGI BlackKnight:
902 for (s = -1; s <= 1; s += 2) {
903 if (rf > 1 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
904 !SameColor(board[rf][ff], board[rf - 2][ff + s])) {
905 callback(board, flags, NormalMove,
906 rf, ff, rf - 2, ff + s, closure);
913 for (d = 0; d <= 1; d++)
914 for (s = -1; s <= 1; s += 2) {
917 rt = rf + (i * s) * d;
918 ft = ff + (i * s) * (1 - d);
919 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
920 if (m == 0 && board[rt][ft] == EmptySquare)
921 callback(board, flags, NormalMove,
922 rf, ff, rt, ft, closure);
923 if (m == 1 && board[rt][ft] != EmptySquare &&
924 !SameColor(board[rf][ff], board[rt][ft]) )
925 callback(board, flags, NormalMove,
926 rf, ff, rt, ft, closure);
927 if (board[rt][ft] != EmptySquare && m++) break;
932 /* Gold General (and all its promoted versions) . First do the */
933 /* diagonal forward steps, then proceed as normal Wazir */
934 case SHOGI (PROMO WhitePawn):
935 if(gameInfo.variant == VariantShogi) goto WhiteGold;
936 case SHOGI (PROMO BlackPawn):
937 if(gameInfo.variant == VariantShogi) goto BlackGold;
938 SlideVertical(board, flags, rf, ff, callback, closure);
941 case SHOGI (PROMO WhiteKnight):
942 if(gameInfo.variant == VariantShogi) goto WhiteGold;
943 case SHOGI BlackDrunk:
944 case SHOGI BlackAlfil:
945 Ferz(board, flags, rf, ff, callback, closure);
946 StepSideways(board, flags, rf, ff, callback, closure);
947 StepBackward(board, flags, rf, ff, callback, closure);
950 case SHOGI (PROMO BlackKnight):
951 if(gameInfo.variant == VariantShogi) goto BlackGold;
952 case SHOGI WhiteDrunk:
953 case SHOGI WhiteAlfil:
954 Ferz(board, flags, rf, ff, callback, closure);
955 StepSideways(board, flags, rf, ff, callback, closure);
956 StepForward(board, flags, rf, ff, callback, closure);
962 if(gameInfo.variant == VariantShogi) goto BlackGold;
963 SlideVertical(board, flags, rf, ff, callback, closure);
964 Ferz(board, flags, rf, ff, callback, closure);
965 StepSideways(board, flags, rf, ff, callback, closure);
968 case SHOGI (PROMO WhiteQueen):
969 case SHOGI WhiteTokin:
970 case SHOGI WhiteWazir:
972 StepDiagForward(board, flags, rf, ff, callback, closure);
973 Wazir(board, flags, rf, ff, callback, closure);
976 case SHOGI (PROMO BlackQueen):
977 case SHOGI BlackTokin:
978 case SHOGI BlackWazir:
980 StepDiagBackward(board, flags, rf, ff, callback, closure);
981 Wazir(board, flags, rf, ff, callback, closure);
986 Wazir(board, flags, rf, ff, callback, closure);
989 case SHOGI WhiteMarshall:
990 case SHOGI BlackMarshall:
991 Ferz(board, flags, rf, ff, callback, closure);
992 for (d = 0; d <= 1; d++)
993 for (s = -2; s <= 2; s += 4) {
995 ft = ff + s * (1 - d);
996 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) continue;
997 if (!SameColor(board[rf][ff], board[rt][ft]) )
998 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
1002 case SHOGI WhiteAngel:
1003 case SHOGI BlackAngel:
1004 Wazir(board, flags, rf, ff, callback, closure);
1008 /* [HGM] support Shatranj pieces */
1009 for (rs = -1; rs <= 1; rs += 2)
1010 for (fs = -1; fs <= 1; fs += 2) {
1013 if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
1014 && ( gameInfo.variant != VariantXiangqi ||
1015 board[rf+rs][ff+fs] == EmptySquare && (2*rf < BOARD_HEIGHT) == (2*rt < BOARD_HEIGHT) )
1017 && !SameColor(board[rf][ff], board[rt][ft]))
1018 callback(board, flags, NormalMove,
1019 rf, ff, rt, ft, closure);
1020 if(gameInfo.variant == VariantShatranj || gameInfo.variant == VariantCourier ||
1021 gameInfo.variant == VariantChu || gameInfo.variant == VariantXiangqi) continue; // classical Alfil
1022 rt = rf + rs; // in unknown variant we assume Modern Elephant, which can also do one step
1024 if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
1025 && !SameColor(board[rf][ff], board[rt][ft]))
1026 callback(board, flags, NormalMove,
1027 rf, ff, rt, ft, closure);
1029 if(gameInfo.variant == VariantSpartan)
1030 for(fs = -1; fs <= 1; fs += 2) {
1032 if (!(ft < BOARD_LEFT || ft >= BOARD_RGHT) && board[rf][ft] == EmptySquare)
1033 callback(board, flags, NormalMove, rf, ff, rf, ft, closure);
1037 /* Make Dragon-Horse also do Dababba moves outside Shogi, for better disambiguation in variant Fairy */
1040 if(gameInfo.variant == VariantChuChess) goto DragonHorse;
1041 for (d = 0; d <= 1; d++) // Dababba moves that Rook cannot do
1042 for (s = -2; s <= 2; s += 4) {
1044 ft = ff + s * (1 - d);
1045 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) continue;
1046 if (SameColor(board[rf][ff], board[rt][ft])) continue;
1047 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
1050 /* Shogi Dragon Horse has to continue with Wazir after Bishop */
1051 case SHOGI WhiteCardinal:
1052 case SHOGI BlackCardinal:
1053 case SHOGI WhitePCardinal:
1054 case SHOGI BlackPCardinal:
1056 Bishop(board, flags, rf, ff, callback, closure);
1057 Wazir(board, flags, rf, ff, callback, closure);
1060 /* Capablanca Archbishop continues as Knight */
1063 Knight(board, flags, rf, ff, callback, closure);
1065 /* Shogi Bishops are ordinary Bishops */
1066 case SHOGI WhiteBishop:
1067 case SHOGI BlackBishop:
1068 case SHOGI WhitePBishop:
1069 case SHOGI BlackPBishop:
1072 Bishop(board, flags, rf, ff, callback, closure);
1075 /* Shogi Lance is unlike anything, and asymmetric at that */
1076 case SHOGI WhiteQueen:
1077 if(gameInfo.variant == VariantChu) goto doQueen;
1081 if (rt >= BOARD_HEIGHT) break;
1082 if (SameColor(board[rf][ff], board[rt][ft])) break;
1083 callback(board, flags, NormalMove,
1084 rf, ff, rt, ft, closure);
1085 if (board[rt][ft] != EmptySquare) break;
1089 case SHOGI BlackQueen:
1090 if(gameInfo.variant == VariantChu) goto doQueen;
1095 if (SameColor(board[rf][ff], board[rt][ft])) break;
1096 callback(board, flags, NormalMove,
1097 rf, ff, rt, ft, closure);
1098 if (board[rt][ft] != EmptySquare) break;
1102 /* Make Dragon-King Dababba & Rook-like outside Shogi, for better disambiguation in variant Fairy */
1105 if(gameInfo.variant == VariantChuChess) goto DragonKing;
1106 for (d = 0; d <= 1; d++) // Dababba moves that Rook cannot do
1107 for (s = -2; s <= 2; s += 4) {
1109 ft = ff + s * (1 - d);
1110 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) continue;
1111 if (board[rf+rt>>1][ff+ft>>1] == EmptySquare && gameInfo.variant != VariantSpartan) continue;
1112 if (SameColor(board[rf][ff], board[rt][ft])) continue;
1113 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
1115 if(gameInfo.variant == VariantSpartan) // in Spartan Chess restrict range to modern Dababba
1116 Wazir(board, flags, rf, ff, callback, closure);
1118 Rook(board, flags, rf, ff, callback, closure);
1121 /* Shogi Dragon King has to continue as Ferz after Rook moves */
1122 case SHOGI WhiteDragon:
1123 case SHOGI BlackDragon:
1124 case SHOGI WhitePDragon:
1125 case SHOGI BlackPDragon:
1127 Rook(board, flags, rf, ff, callback, closure);
1128 Ferz(board, flags, rf, ff, callback, closure);
1132 /* Capablanca Chancellor sets flag to continue as Knight */
1135 Rook(board, flags, rf, ff, callback, closure);
1136 if(gameInfo.variant == VariantSpartan) // in Spartan Chess Chancellor is used for Dragon King.
1137 Ferz(board, flags, rf, ff, callback, closure);
1139 Knight(board, flags, rf, ff, callback, closure);
1142 /* Shogi Rooks are ordinary Rooks */
1143 case SHOGI WhiteRook:
1144 case SHOGI BlackRook:
1145 case SHOGI WhitePRook:
1146 case SHOGI BlackPRook:
1149 Rook(board, flags, rf, ff, callback, closure);
1154 case SHOGI WhiteMother:
1155 case SHOGI BlackMother:
1157 Rook(board, flags, rf, ff, callback, closure);
1158 Bishop(board, flags, rf, ff, callback, closure);
1161 case SHOGI WhitePawn:
1162 StepForward(board, flags, rf, ff, callback, closure);
1165 case SHOGI BlackPawn:
1166 StepBackward(board, flags, rf, ff, callback, closure);
1170 if(gameInfo.variant != VariantMakruk && gameInfo.variant != VariantASEAN) goto commoner;
1171 case SHOGI WhiteFerz:
1172 Ferz(board, flags, rf, ff, callback, closure);
1173 StepForward(board, flags, rf, ff, callback, closure);
1177 if(gameInfo.variant != VariantMakruk && gameInfo.variant != VariantASEAN) goto commoner;
1178 case SHOGI BlackFerz:
1179 StepBackward(board, flags, rf, ff, callback, closure);
1183 /* [HGM] support Shatranj pieces */
1184 Ferz(board, flags, rf, ff, callback, closure);
1189 Knight(board, flags, rf, ff, callback, closure); // [HGM] superchess: use for Centaur
1192 case SHOGI WhiteMonarch:
1193 case SHOGI BlackMonarch:
1194 case SHOGI WhiteKing:
1195 case SHOGI BlackKing:
1198 Ferz(board, flags, rf, ff, callback, closure);
1199 Wazir(board, flags, rf, ff, callback, closure);
1202 case WhiteNightrider:
1203 case BlackNightrider:
1204 for (i = -1; i <= 1; i += 2)
1205 for (j = -1; j <= 1; j += 2)
1206 for (s = 1; s <= 2; s++) { int k;
1209 ft = ff + k*j*(3-s);
1210 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
1211 if (SameColor(board[rf][ff], board[rt][ft])) break;
1212 callback(board, flags, NormalMove,
1213 rf, ff, rt, ft, closure);
1214 if (board[rt][ft] != EmptySquare) break;
1220 Bishop(board, flags, rf, ff, callback, closure);
1221 Rook(board, flags, rf, ff, callback, closure);
1222 Knight(board, flags, rf, ff, callback, closure);
1225 // Use Lance as Berolina / Spartan Pawn.
1227 if(gameInfo.variant == VariantSuper) goto Amazon;
1228 if (rf < BOARD_HEIGHT-1 && BlackPiece(board[rf + 1][ff]))
1229 callback(board, flags,
1230 rf >= BOARD_HEIGHT-1-promoRank ? WhitePromotion : NormalMove,
1231 rf, ff, rf + 1, ff, closure);
1232 for (s = -1; s <= 1; s += 2) {
1233 if (rf < BOARD_HEIGHT-1 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT && board[rf + 1][ff + s] == EmptySquare)
1234 callback(board, flags,
1235 rf >= BOARD_HEIGHT-1-promoRank ? WhitePromotion : NormalMove,
1236 rf, ff, rf + 1, ff + s, closure);
1237 if (rf == 1 && ff + 2*s >= BOARD_LEFT && ff + 2*s < BOARD_RGHT && board[3][ff + 2*s] == EmptySquare )
1238 callback(board, flags, NormalMove, rf, ff, 3, ff + 2*s, closure);
1243 if(gameInfo.variant == VariantSuper) goto Amazon;
1244 if (rf > 0 && WhitePiece(board[rf - 1][ff]))
1245 callback(board, flags,
1246 rf <= promoRank ? BlackPromotion : NormalMove,
1247 rf, ff, rf - 1, ff, closure);
1248 for (s = -1; s <= 1; s += 2) {
1249 if (rf > 0 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT && board[rf - 1][ff + s] == EmptySquare)
1250 callback(board, flags,
1251 rf <= promoRank ? BlackPromotion : NormalMove,
1252 rf, ff, rf - 1, ff + s, closure);
1253 if (rf == BOARD_HEIGHT-2 && ff + 2*s >= BOARD_LEFT && ff + 2*s < BOARD_RGHT && board[rf-2][ff + 2*s] == EmptySquare )
1254 callback(board, flags, NormalMove, rf, ff, rf-2, ff + 2*s, closure);
1258 case SHOGI WhiteNothing:
1259 case SHOGI BlackNothing:
1260 case SHOGI WhiteLion:
1261 case SHOGI BlackLion:
1264 for(rt = rf - 2; rt <= rf + 2; rt++) for(ft = ff - 2; ft <= ff + 2; ft++) {
1265 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) continue;
1266 if (!(ff == ft && rf == rt) && SameColor(board[rf][ff], board[rt][ft])) continue;
1267 i = (killX >= 0 && (rt-killY)*(rt-killY) + (killX-ft)*(killX-ft) < 3); legNr += 2*i;
1268 callback(board, flags, (rt-rf)*(rt-rf) + (ff-ft)*(ff-ft) < 3 && board[rt][ft] != EmptySquare && !i ? FirstLeg : NormalMove,
1269 rf, ff, rt, ft, closure);
1274 case SHOGI WhiteFalcon:
1275 case SHOGI BlackFalcon:
1276 case SHOGI WhitePDagger:
1277 case SHOGI BlackPDagger:
1278 SlideSideways(board, flags, rf, ff, callback, closure);
1279 StepVertical(board, flags, rf, ff, callback, closure);
1282 case SHOGI WhiteCobra:
1283 case SHOGI BlackCobra:
1284 StepVertical(board, flags, rf, ff, callback, closure);
1287 case SHOGI (PROMO WhiteFerz):
1288 if(gameInfo.variant == VariantShogi) goto WhiteGold;
1289 case SHOGI (PROMO BlackFerz):
1290 if(gameInfo.variant == VariantShogi) goto BlackGold;
1291 case SHOGI WhitePSword:
1292 case SHOGI BlackPSword:
1293 SlideVertical(board, flags, rf, ff, callback, closure);
1294 StepSideways(board, flags, rf, ff, callback, closure);
1297 case SHOGI WhiteUnicorn:
1298 case SHOGI BlackUnicorn:
1299 Ferz(board, flags, rf, ff, callback, closure);
1300 StepVertical(board, flags, rf, ff, callback, closure);
1303 case SHOGI WhiteMan:
1304 StepDiagForward(board, flags, rf, ff, callback, closure);
1305 StepVertical(board, flags, rf, ff, callback, closure);
1308 case SHOGI BlackMan:
1309 StepDiagBackward(board, flags, rf, ff, callback, closure);
1310 StepVertical(board, flags, rf, ff, callback, closure);
1313 case SHOGI WhiteHCrown:
1314 case SHOGI BlackHCrown:
1315 Bishop(board, flags, rf, ff, callback, closure);
1316 SlideSideways(board, flags, rf, ff, callback, closure);
1319 case SHOGI WhiteCrown:
1320 case SHOGI BlackCrown:
1321 Bishop(board, flags, rf, ff, callback, closure);
1322 SlideVertical(board, flags, rf, ff, callback, closure);
1325 case SHOGI WhiteCat:
1326 Sting(board, flags, rf, ff, 1, 0, callback, closure);
1327 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1328 if(killX >= 0) break;
1329 Bishop(board, flags, rf, ff, callback, closure);
1330 SlideSideways(board, flags, rf, ff, callback, closure);
1331 SlideBackward(board, flags, rf, ff, callback, closure);
1334 case SHOGI BlackCat:
1335 Sting(board, flags, rf, ff, -1, 0, callback, closure);
1336 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1337 if(killX >= 0) break;
1338 Bishop(board, flags, rf, ff, callback, closure);
1339 SlideSideways(board, flags, rf, ff, callback, closure);
1340 SlideForward(board, flags, rf, ff, callback, closure);
1343 case SHOGI WhiteDagger:
1344 Sting(board, flags, rf, ff, 1, 1, callback, closure);
1345 Sting(board, flags, rf, ff, 1, -1, callback, closure);
1346 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1347 if(killX >= 0) break;
1348 Rook(board, flags, rf, ff, callback, closure);
1349 SlideDiagBackward(board, flags, rf, ff, callback, closure);
1352 case SHOGI BlackDagger:
1353 Sting(board, flags, rf, ff, -1, 1, callback, closure);
1354 Sting(board, flags, rf, ff, -1, -1, callback, closure);
1355 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1356 if(killX >= 0) break;
1357 Rook(board, flags, rf, ff, callback, closure);
1358 SlideDiagForward(board, flags, rf, ff, callback, closure);
1361 case SHOGI WhiteDolphin:
1362 case SHOGI BlackHorse:
1363 SlideDiagBackward(board, flags, rf, ff, callback, closure);
1364 SlideVertical(board, flags, rf, ff, callback, closure);
1367 case SHOGI BlackDolphin:
1368 case SHOGI WhiteHorse:
1369 SlideDiagForward(board, flags, rf, ff, callback, closure);
1370 SlideVertical(board, flags, rf, ff, callback, closure);
1373 case SHOGI WhiteLance:
1374 SlideForward(board, flags, rf, ff, callback, closure);
1377 case SHOGI BlackLance:
1378 SlideBackward(board, flags, rf, ff, callback, closure);
1381 case WhiteFalcon: // [HGM] wild: for wildcards, self-capture symbolizes move to anywhere
1385 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1398 int rFilter, fFilter; // [HGM] speed: sorry, but I get a bit tired of this closure madness
1399 Board xqCheckers, nullBoard;
1401 extern void GenLegalCallback P((Board board, int flags, ChessMove kind,
1402 int rf, int ff, int rt, int ft,
1406 GenLegalCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1408 register GenLegalClosure *cl = (GenLegalClosure *) closure;
1410 if(rFilter >= 0 && rFilter != rt || fFilter >= 0 && fFilter != ft) return; // [HGM] speed: ignore moves with wrong to-square
1412 if (board[EP_STATUS] == EP_IRON_LION && (board[rt][ft] == WhiteLion || board[rt][ft] == BlackLion)) return; //[HGM] lion
1414 if (!(flags & F_IGNORE_CHECK) ) {
1415 int check, promo = (gameInfo.variant == VariantSpartan && kind == BlackPromotion);
1418 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++)
1419 kings += (board[r][f] == BlackKing);
1423 board[rf][ff] = BlackKing; // [HGM] spartan: promote to King before check-test
1425 check = CheckTest(board, flags, rf, ff, rt, ft,
1426 kind == WhiteCapturesEnPassant ||
1427 kind == BlackCapturesEnPassant);
1428 if(promo) board[rf][ff] = BlackLance;
1431 if (flags & F_ATOMIC_CAPTURE) {
1432 if (board[rt][ft] != EmptySquare ||
1433 kind == WhiteCapturesEnPassant || kind == BlackCapturesEnPassant) {
1435 ChessSquare king = (flags & F_WHITE_ON_MOVE) ? WhiteKing : BlackKing;
1436 if (board[rf][ff] == king) return;
1437 for (r = rt-1; r <= rt+1; r++) {
1438 for (f = ft-1; f <= ft+1; f++) {
1439 if (r >= 0 && r < BOARD_HEIGHT && f >= BOARD_LEFT && f < BOARD_RGHT &&
1440 board[r][f] == king) return;
1445 cl->cb(board, flags, kind, rf, ff, rt, ft, cl->cl);
1452 int captures; // [HGM] losers
1453 } LegalityTestClosure;
1456 /* Like GenPseudoLegal, but (1) include castling moves, (2) unless
1457 F_IGNORE_CHECK is set in the flags, omit moves that would leave the
1458 king in check, and (3) if F_ATOMIC_CAPTURE is set in the flags, omit
1459 moves that would destroy your own king. The CASTLE_OK flags are
1460 true if castling is not yet ruled out by a move of the king or
1461 rook. Return TRUE if the player on move is currently in check and
1462 F_IGNORE_CHECK is not set. [HGM] add castlingRights parameter */
1464 GenLegal (Board board, int flags, MoveCallback callback, VOIDSTAR closure, ChessSquare filter)
1467 int ff, ft, k, left, right, swap;
1468 int ignoreCheck = (flags & F_IGNORE_CHECK) != 0;
1469 ChessSquare wKing = WhiteKing, bKing = BlackKing, *castlingRights = board[CASTLING];
1470 int inCheck = !ignoreCheck && CheckTest(board, flags, -1, -1, -1, -1, FALSE); // kludge alert: this would mark pre-existing checkers if status==1
1475 xqCheckers[EP_STATUS] *= 2; // quasi: if previous CheckTest has been marking, we now set flag for suspending same checkers
1476 if(filter == EmptySquare) rFilter = fFilter = -1; // [HGM] speed: do not filter on square if we do not filter on piece
1477 GenPseudoLegal(board, flags, GenLegalCallback, (VOIDSTAR) &cl, filter);
1479 if (inCheck) return TRUE;
1481 /* Generate castling moves */
1482 if(gameInfo.variant == VariantKnightmate) { /* [HGM] Knightmate */
1483 wKing = WhiteUnicorn; bKing = BlackUnicorn;
1486 p = (flags & F_WHITE_ON_MOVE ? pieceDesc[wKing] : pieceDesc[bKing]);
1487 if(p && strchr(p, 'O')) return FALSE; // [HGM] gen: castlings were already generated from string
1489 for (ff = BOARD_WIDTH>>1; ff >= (BOARD_WIDTH-1)>>1; ff-- /*ics wild 1*/) {
1490 if ((flags & F_WHITE_ON_MOVE) &&
1491 (flags & F_WHITE_KCASTLE_OK) &&
1492 board[0][ff] == wKing &&
1493 board[0][ff + 1] == EmptySquare &&
1494 board[0][ff + 2] == EmptySquare &&
1495 board[0][BOARD_RGHT-3] == EmptySquare &&
1496 board[0][BOARD_RGHT-2] == EmptySquare &&
1497 board[0][BOARD_RGHT-1] == WhiteRook &&
1498 castlingRights[0] != NoRights && /* [HGM] check rights */
1499 ( castlingRights[2] == ff || castlingRights[6] == ff ) &&
1501 (!CheckTest(board, flags, 0, ff, 0, ff + 1, FALSE) &&
1502 !CheckTest(board, flags, 0, ff, 0, BOARD_RGHT-3, FALSE) &&
1503 (gameInfo.variant != VariantJanus || !CheckTest(board, flags, 0, ff, 0, BOARD_RGHT-2, FALSE)) &&
1504 !CheckTest(board, flags, 0, ff, 0, ff + 2, FALSE)))) {
1506 callback(board, flags,
1507 ff==BOARD_WIDTH>>1 ? WhiteKingSideCastle : WhiteKingSideCastleWild,
1508 0, ff, 0, ff + ((gameInfo.boardWidth+2)>>2) + (gameInfo.variant == VariantJanus), closure);
1510 if ((flags & F_WHITE_ON_MOVE) &&
1511 (flags & F_WHITE_QCASTLE_OK) &&
1512 board[0][ff] == wKing &&
1513 board[0][ff - 1] == EmptySquare &&
1514 board[0][ff - 2] == EmptySquare &&
1515 board[0][BOARD_LEFT+2] == EmptySquare &&
1516 board[0][BOARD_LEFT+1] == EmptySquare &&
1517 board[0][BOARD_LEFT+0] == WhiteRook &&
1518 castlingRights[1] != NoRights && /* [HGM] check rights */
1519 ( castlingRights[2] == ff || castlingRights[6] == ff ) &&
1521 (!CheckTest(board, flags, 0, ff, 0, ff - 1, FALSE) &&
1522 !CheckTest(board, flags, 0, ff, 0, BOARD_LEFT+3, FALSE) &&
1523 !CheckTest(board, flags, 0, ff, 0, ff - 2, FALSE)))) {
1525 callback(board, flags,
1526 ff==BOARD_WIDTH>>1 ? WhiteQueenSideCastle : WhiteQueenSideCastleWild,
1527 0, ff, 0, ff - ((gameInfo.boardWidth+2)>>2), closure);
1529 if (!(flags & F_WHITE_ON_MOVE) &&
1530 (flags & F_BLACK_KCASTLE_OK) &&
1531 board[BOARD_HEIGHT-1][ff] == bKing &&
1532 board[BOARD_HEIGHT-1][ff + 1] == EmptySquare &&
1533 board[BOARD_HEIGHT-1][ff + 2] == EmptySquare &&
1534 board[BOARD_HEIGHT-1][BOARD_RGHT-3] == EmptySquare &&
1535 board[BOARD_HEIGHT-1][BOARD_RGHT-2] == EmptySquare &&
1536 board[BOARD_HEIGHT-1][BOARD_RGHT-1] == BlackRook &&
1537 castlingRights[3] != NoRights && /* [HGM] check rights */
1538 ( castlingRights[5] == ff || castlingRights[7] == ff ) &&
1540 (!CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff + 1, FALSE) &&
1541 !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, BOARD_RGHT-3, FALSE) &&
1542 (gameInfo.variant != VariantJanus || !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, BOARD_RGHT-2, FALSE)) &&
1543 !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff + 2, FALSE)))) {
1545 callback(board, flags,
1546 ff==BOARD_WIDTH>>1 ? BlackKingSideCastle : BlackKingSideCastleWild,
1547 BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff + ((gameInfo.boardWidth+2)>>2) + (gameInfo.variant == VariantJanus), closure);
1549 if (!(flags & F_WHITE_ON_MOVE) &&
1550 (flags & F_BLACK_QCASTLE_OK) &&
1551 board[BOARD_HEIGHT-1][ff] == bKing &&
1552 board[BOARD_HEIGHT-1][ff - 1] == EmptySquare &&
1553 board[BOARD_HEIGHT-1][ff - 2] == EmptySquare &&
1554 board[BOARD_HEIGHT-1][BOARD_LEFT+2] == EmptySquare &&
1555 board[BOARD_HEIGHT-1][BOARD_LEFT+1] == EmptySquare &&
1556 board[BOARD_HEIGHT-1][BOARD_LEFT+0] == BlackRook &&
1557 castlingRights[4] != NoRights && /* [HGM] check rights */
1558 ( castlingRights[5] == ff || castlingRights[7] == ff ) &&
1560 (!CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff - 1, FALSE) &&
1561 !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, BOARD_LEFT+3, FALSE) &&
1562 !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff - 2, FALSE)))) {
1564 callback(board, flags,
1565 ff==BOARD_WIDTH>>1 ? BlackQueenSideCastle : BlackQueenSideCastleWild,
1566 BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff - ((gameInfo.boardWidth+2)>>2), closure);
1570 if((swap = gameInfo.variant == VariantSChess) || flags & F_FRC_TYPE_CASTLING) {
1572 /* generate all potential FRC castling moves (KxR), ignoring flags */
1573 /* [HGM] test if the Rooks we find have castling rights */
1574 /* In S-Chess we generate RxK for allowed castlings, for gating at Rook square */
1577 if ((flags & F_WHITE_ON_MOVE) != 0) {
1578 ff = castlingRights[2]; /* King file if we have any rights */
1579 if(ff != NoRights && board[0][ff] == WhiteKing) {
1580 if (appData.debugMode) {
1581 fprintf(debugFP, "FRC castling, %d %d %d %d %d %d\n",
1582 castlingRights[0],castlingRights[1],ff,castlingRights[3],castlingRights[4],castlingRights[5]);
1584 ft = castlingRights[0]; /* Rook file if we have H-side rights */
1586 right = BOARD_RGHT-2;
1587 if(ff == BOARD_RGHT-2) left = right = ff-1; /* special case */
1588 for(k=left; k<=right && ft != NoRights; k++) /* first test if blocked */
1589 if(k != ft && board[0][k] != EmptySquare) ft = NoRights;
1590 for(k=left; k<right && ft != NoRights; k++) /* then if not checked */
1591 if(!ignoreCheck && CheckTest(board, flags, 0, ff, 0, k, FALSE)) ft = NoRights;
1592 if(ft != NoRights && board[0][ft] == WhiteRook) {
1593 if(flags & F_FRC_TYPE_CASTLING) callback(board, flags, WhiteHSideCastleFR, 0, ff, 0, ft, closure);
1594 if(swap) callback(board, flags, WhiteHSideCastleFR, 0, ft, 0, ff, closure);
1597 ft = castlingRights[1]; /* Rook file if we have A-side rights */
1598 left = BOARD_LEFT+2;
1600 if(ff <= BOARD_LEFT+2) { left = ff+1; right = BOARD_LEFT+3; }
1601 for(k=left; k<=right && ft != NoRights; k++) /* first test if blocked */
1602 if(k != ft && board[0][k] != EmptySquare) ft = NoRights;
1603 if(ft == 0 && ff != 1 && board[0][1] != EmptySquare) ft = NoRights; /* Rook can be blocked on b1 */
1604 if(ff > BOARD_LEFT+2)
1605 for(k=left+1; k<=right && ft != NoRights; k++) /* then if not checked */
1606 if(!ignoreCheck && CheckTest(board, flags, 0, ff, 0, k, FALSE)) ft = NoRights;
1607 if(ft != NoRights && board[0][ft] == WhiteRook) {
1608 if(flags & F_FRC_TYPE_CASTLING) callback(board, flags, WhiteASideCastleFR, 0, ff, 0, ft, closure);
1609 if(swap) callback(board, flags, WhiteASideCastleFR, 0, ft, 0, ff, closure);
1613 ff = castlingRights[5]; /* King file if we have any rights */
1614 if(ff != NoRights && board[BOARD_HEIGHT-1][ff] == BlackKing) {
1615 ft = castlingRights[3]; /* Rook file if we have H-side rights */
1617 right = BOARD_RGHT-2;
1618 if(ff == BOARD_RGHT-2) left = right = ff-1; /* special case */
1619 for(k=left; k<=right && ft != NoRights; k++) /* first test if blocked */
1620 if(k != ft && board[BOARD_HEIGHT-1][k] != EmptySquare) ft = NoRights;
1621 for(k=left; k<right && ft != NoRights; k++) /* then if not checked */
1622 if(!ignoreCheck && CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, k, FALSE)) ft = NoRights;
1623 if(ft != NoRights && board[BOARD_HEIGHT-1][ft] == BlackRook) {
1624 if(flags & F_FRC_TYPE_CASTLING) callback(board, flags, BlackHSideCastleFR, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ft, closure);
1625 if(swap) callback(board, flags, BlackHSideCastleFR, BOARD_HEIGHT-1, ft, BOARD_HEIGHT-1, ff, closure);
1628 ft = castlingRights[4]; /* Rook file if we have A-side rights */
1629 left = BOARD_LEFT+2;
1631 if(ff <= BOARD_LEFT+2) { left = ff+1; right = BOARD_LEFT+3; }
1632 for(k=left; k<=right && ft != NoRights; k++) /* first test if blocked */
1633 if(k != ft && board[BOARD_HEIGHT-1][k] != EmptySquare) ft = NoRights;
1634 if(ft == 0 && ff != 1 && board[BOARD_HEIGHT-1][1] != EmptySquare) ft = NoRights; /* Rook can be blocked on b8 */
1635 if(ff > BOARD_LEFT+2)
1636 for(k=left+1; k<=right && ft != NoRights; k++) /* then if not checked */
1637 if(!ignoreCheck && CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, k, FALSE)) ft = NoRights;
1638 if(ft != NoRights && board[BOARD_HEIGHT-1][ft] == BlackRook) {
1639 if(flags & F_FRC_TYPE_CASTLING) callback(board, flags, BlackASideCastleFR, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ft, closure);
1640 if(swap) callback(board, flags, BlackASideCastleFR, BOARD_HEIGHT-1, ft, BOARD_HEIGHT-1, ff, closure);
1657 extern void CheckTestCallback P((Board board, int flags, ChessMove kind,
1658 int rf, int ff, int rt, int ft,
1663 CheckTestCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1665 register CheckTestClosure *cl = (CheckTestClosure *) closure;
1667 if (rt == cl->rking && ft == cl->fking) {
1668 if(xqCheckers[EP_STATUS] >= 2 && xqCheckers[rf][ff]) return; // checker is piece with suspended checking power
1670 xqCheckers[rf][ff] = xqCheckers[EP_STATUS] & 1; // remember who is checking (if status == 1)
1672 if( board[EP_STATUS] == EP_ROYAL_LION && (board[rt][ft] == WhiteLion || board[rt][ft] == BlackLion)
1673 && (gameInfo.variant != VariantLion || board[rf][ff] != WhiteKing && board[rf][ff] != BlackKing) )
1674 cl->check++; // [HGM] lion: forbidden counterstrike against Lion equated to putting yourself in check
1678 /* If the player on move were to move from (rf, ff) to (rt, ft), would
1679 he leave himself in check? Or if rf == -1, is the player on move
1680 in check now? enPassant must be TRUE if the indicated move is an
1681 e.p. capture. The possibility of castling out of a check along the
1682 back rank is not accounted for (i.e., we still return nonzero), as
1683 this is illegal anyway. Return value is the number of times the
1684 king is in check. */
1686 CheckTest (Board board, int flags, int rf, int ff, int rt, int ft, int enPassant)
1688 CheckTestClosure cl;
1689 ChessSquare king = flags & F_WHITE_ON_MOVE ? WhiteKing : BlackKing;
1690 ChessSquare captured = EmptySquare, ep=0, trampled=0, trampled2 = 0;
1691 int saveKill = killX;
1692 /* Suppress warnings on uninitialized variables */
1694 if(gameInfo.variant == VariantXiangqi)
1695 king = flags & F_WHITE_ON_MOVE ? WhiteWazir : BlackWazir;
1696 if(gameInfo.variant == VariantKnightmate)
1697 king = flags & F_WHITE_ON_MOVE ? WhiteUnicorn : BlackUnicorn;
1698 if(gameInfo.variant == VariantChu || gameInfo.variant == VariantShogi) { // strictly speaking this is not needed, as Chu officially has no check
1699 int r, f, k = king, royals=0, prince = flags & F_WHITE_ON_MOVE ? WhiteMonarch : BlackMonarch;
1700 if(gameInfo.variant == VariantShogi) prince -= 11; // White/BlackFalcon
1701 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++) {
1702 if(board[r][f] == k || board[r][f] == prince) {
1703 if(++royals > 1) return FALSE; // no check if we have two royals (ignores double captureby Lion!)
1704 king = board[r][f]; // remember hich one we had
1711 captured = board[rf][ft];
1712 board[rf][ft] = EmptySquare;
1714 captured = board[rt][ft];
1716 trampled = board[killY][killX]; board[killY][killX] = EmptySquare; killX = -1; saveKill += (kill2X << 16) + (1 << 30);
1717 if(kill2X >= 0) { trampled2 = board[kill2Y][kill2X]; board[kill2Y][kill2X] = EmptySquare; kill2X = -1; }
1720 if(rf == DROP_RANK) board[rt][ft] = ff; else { // [HGM] drop
1721 board[rt][ft] = board[rf][ff];
1722 if(rf != rt || ff != ft) board[rf][ff] = EmptySquare;
1724 ep = board[EP_STATUS];
1725 if( captured == WhiteLion || captured == BlackLion ) { // [HGM] lion: Chu Lion-capture rules
1726 ChessSquare victim = saveKill < 0 ? EmptySquare : trampled;
1727 if( (board[rt][ft] == WhiteLion || board[rt][ft] == BlackLion) && // capturer is Lion
1728 (ff - ft > 1 || ft - ff > 1 || rf - rt > 1 || rt - rf > 1) && // captures from a distance
1729 (victim == EmptySquare || victim == WhitePawn || victim == BlackPawn // no or worthless 'bridge'
1730 || victim == WhiteCobra || victim == BlackCobra) ) // (Pawn or Go Between)
1731 board[EP_STATUS] = EP_ROYAL_LION; // on distant Lion x Lion victim must not be pseudo-legally protected
1735 /* For compatibility with ICS wild 9, we scan the board in the
1736 order a1, a2, a3, ... b1, b2, ..., h8 to find the first king,
1737 and we test only whether that one is in check. */
1738 for (cl.fking = BOARD_LEFT+0; cl.fking < BOARD_RGHT; cl.fking++)
1739 for (cl.rking = 0; cl.rking < BOARD_HEIGHT; cl.rking++) {
1740 if (board[cl.rking][cl.fking] == king) {
1742 if(gameInfo.variant == VariantXiangqi) {
1743 /* [HGM] In Xiangqi opposing Kings means check as well */
1745 dir = (king >= BlackPawn) ? -1 : 1;
1746 for( i=cl.rking+dir; i>=0 && i<BOARD_HEIGHT &&
1747 board[i][cl.fking] == EmptySquare; i+=dir );
1748 if(i>=0 && i<BOARD_HEIGHT &&
1749 board[i][cl.fking] == (dir>0 ? BlackWazir : WhiteWazir) )
1752 GenPseudoLegal(board, flags ^ F_WHITE_ON_MOVE, CheckTestCallback, (VOIDSTAR) &cl, EmptySquare);
1753 if(gameInfo.variant != VariantSpartan || cl.check == 0) // in Spartan Chess go on to test if other King is checked too
1754 goto undo_move; /* 2-level break */
1761 if(rf != DROP_RANK) // [HGM] drop
1762 board[rf][ff] = board[rt][ft];
1764 board[rf][ft] = captured;
1765 board[rt][ft] = EmptySquare;
1768 if(saveKill & 1<<30) board[kill2Y][kill2X = saveKill >> 16 & 0xFFF] = trampled2;
1769 board[killY][killX = saveKill & 0xFFF] = trampled;
1771 board[rt][ft] = captured;
1773 board[EP_STATUS] = ep;
1776 return cl.fking < BOARD_RGHT ? cl.check : 1000; // [HGM] atomic: return 1000 if we have no king
1780 HasLion (Board board, int flags)
1782 int lion = F_WHITE_ON_MOVE & flags ? WhiteLion : BlackLion;
1784 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++)
1785 if(board[r][f] == lion) return 1;
1790 LegalDrop (Board board, int flags, ChessSquare piece, int rt, int ft)
1791 { // [HGM] put drop legality testing in separate routine for clarity
1793 if(appData.debugMode) fprintf(debugFP, "LegalDrop: %d @ %d,%d)\n", piece, ft, rt);
1794 if(board[rt][ft] != EmptySquare) return ImpossibleMove; // must drop to empty square
1795 n = PieceToNumber(piece);
1796 if((gameInfo.holdingsWidth == 0 || (flags & F_WHITE_ON_MOVE ? board[n][BOARD_WIDTH-1] : board[BOARD_HEIGHT-1-n][0]) != piece)
1797 && gameInfo.variant != VariantBughouse) // in bughouse we don't check for availability, because ICS doesn't always tell us
1798 return ImpossibleMove; // piece not available
1799 if(gameInfo.variant == VariantShogi) { // in Shogi lots of drops are forbidden!
1800 if((piece == WhitePawn || piece == WhiteQueen) && rt == BOARD_HEIGHT-1 ||
1801 (piece == BlackPawn || piece == BlackQueen) && rt == 0 ||
1802 piece == WhiteKnight && rt > BOARD_HEIGHT-3 ||
1803 piece == BlackKnight && rt < 2 ) return IllegalMove; // e.g. where dropped piece has no moves
1804 if(piece == WhitePawn || piece == BlackPawn) {
1805 int r, max = 1 + (BOARD_HEIGHT == 7); // two Pawns per file in Tori!
1806 for(r=1; r<BOARD_HEIGHT-1; r++)
1807 if(!(max -= (board[r][ft] == piece))) return IllegalMove; // or there already is a Pawn in file
1808 // should still test if we mate with this Pawn
1810 } else if(gameInfo.variant == VariantSChess) { // only back-rank drops
1811 if (rt != (piece < BlackPawn ? 0 : BOARD_HEIGHT-1)) return IllegalMove;
1813 if( (piece == WhitePawn || piece == BlackPawn) &&
1814 (rt == 0 || rt == BOARD_HEIGHT -1 ) )
1815 return IllegalMove; /* no pawn drops on 1st/8th */
1817 if(appData.debugMode) fprintf(debugFP, "LegalDrop: %d @ %d,%d)\n", piece, ft, rt);
1818 if (!(flags & F_IGNORE_CHECK) &&
1819 CheckTest(board, flags, DROP_RANK, piece, rt, ft, FALSE) ) return IllegalMove;
1820 return flags & F_WHITE_ON_MOVE ? WhiteDrop : BlackDrop;
1823 extern void LegalityTestCallback P((Board board, int flags, ChessMove kind,
1824 int rf, int ff, int rt, int ft,
1828 LegalityTestCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1830 register LegalityTestClosure *cl = (LegalityTestClosure *) closure;
1832 if(board[rt][ft] != EmptySquare || kind==WhiteCapturesEnPassant || kind==BlackCapturesEnPassant)
1833 cl->captures++; // [HGM] losers: count legal captures
1834 if (rf == cl->rf && ff == cl->ff && rt == cl->rt && ft == cl->ft)
1839 LegalityTest (Board board, int flags, int rf, int ff, int rt, int ft, int promoChar)
1841 LegalityTestClosure cl; ChessSquare piece, filterPiece;
1843 if(quickFlag) flags = flags & ~1 | quickFlag & 1; // [HGM] speed: in quick mode quickFlag specifies side-to-move.
1844 if(rf == DROP_RANK) return LegalDrop(board, flags, ff, rt, ft);
1845 piece = filterPiece = board[rf][ff];
1846 if(PieceToChar(piece) == '~') filterPiece = DEMOTED(piece);
1848 /* [HGM] Cobra and Falcon are wildcard pieces; consider all their moves legal */
1849 /* (perhaps we should disallow moves that obviously leave us in check?) */
1850 if((piece == WhiteFalcon || piece == BlackFalcon ||
1851 piece == WhiteCobra || piece == BlackCobra) && gameInfo.variant != VariantChu && !pieceDesc[piece])
1852 return CheckTest(board, flags, rf, ff, rt, ft, FALSE) ? IllegalMove : NormalMove;
1856 cl.rt = rFilter = rt; // [HGM] speed: filter on to-square
1857 cl.ft = fFilter = ft;
1858 cl.kind = IllegalMove;
1859 cl.captures = 0; // [HGM] losers: prepare to count legal captures.
1860 if(flags & F_MANDATORY_CAPTURE) filterPiece = EmptySquare; // [HGM] speed: do not filter in suicide, to find all captures
1861 GenLegal(board, flags, LegalityTestCallback, (VOIDSTAR) &cl, filterPiece);
1862 if((flags & F_MANDATORY_CAPTURE) && cl.captures && board[rt][ft] == EmptySquare
1863 && cl.kind != WhiteCapturesEnPassant && cl.kind != BlackCapturesEnPassant)
1864 return(IllegalMove); // [HGM] losers: if there are legal captures, non-capts are illegal
1866 if(promoChar == 'x') promoChar = NULLCHAR; // [HGM] is this ever the case?
1867 if(gameInfo.variant == VariantSChess && promoChar && promoChar != '=' && board[rf][ff] != WhitePawn && board[rf][ff] != BlackPawn) {
1868 if(board[rf][ff] < BlackPawn) { // white
1869 if(rf != 0) return IllegalMove; // must be on back rank
1870 if(!(board[VIRGIN][ff] & VIRGIN_W)) return IllegalMove; // non-virgin
1871 if(board[PieceToNumber(CharToPiece(ToUpper(promoChar)))][BOARD_WIDTH-2] == 0) return ImpossibleMove;// must be in stock
1872 if(cl.kind == WhiteHSideCastleFR && (ff == BOARD_RGHT-2 || ff == BOARD_RGHT-3)) return ImpossibleMove;
1873 if(cl.kind == WhiteASideCastleFR && (ff == BOARD_LEFT+2 || ff == BOARD_LEFT+3)) return ImpossibleMove;
1875 if(rf != BOARD_HEIGHT-1) return IllegalMove;
1876 if(!(board[VIRGIN][ff] & VIRGIN_B)) return IllegalMove; // non-virgin
1877 if(board[BOARD_HEIGHT-1-PieceToNumber(CharToPiece(ToLower(promoChar)))][1] == 0) return ImpossibleMove;
1878 if(cl.kind == BlackHSideCastleFR && (ff == BOARD_RGHT-2 || ff == BOARD_RGHT-3)) return ImpossibleMove;
1879 if(cl.kind == BlackASideCastleFR && (ff == BOARD_LEFT+2 || ff == BOARD_LEFT+3)) return ImpossibleMove;
1882 if(gameInfo.variant == VariantChu) {
1883 if(cl.kind != NormalMove || promoChar == NULLCHAR || promoChar == '=') return cl.kind;
1884 if(promoChar != '+')
1885 return CharToPiece(promoChar) == EmptySquare ? ImpossibleMove : IllegalMove;
1886 if(PieceToChar(CHUPROMOTED(board[rf][ff])) != '+') {
1887 if(PieceToChar(CHUPROMOTED (board[rf][ff] < BlackPawn ? WhitePawn : BlackPawn)) != '.')
1888 return ImpossibleMove;
1890 return flags & F_WHITE_ON_MOVE ? WhitePromotion : BlackPromotion;
1892 if(gameInfo.variant == VariantShogi) {
1893 /* [HGM] Shogi promotions. '=' means defer */
1894 if(rf != DROP_RANK && cl.kind == NormalMove) {
1895 ChessSquare piece = board[rf][ff];
1896 int zone = BOARD_HEIGHT/3 + (BOARD_HEIGHT == 8);
1898 if(promoChar == PieceToChar(BlackQueen)) promoChar = NULLCHAR; /* [HGM] Kludge */
1899 if(promoChar == 'd' && (piece == WhiteRook || piece == BlackRook) ||
1900 promoChar == 'h' && (piece == WhiteBishop || piece == BlackBishop) ||
1901 promoChar == 'g' && (piece <= WhiteFerz || piece <= BlackFerz && piece >= BlackPawn) )
1902 promoChar = '+'; // allowed ICS notations
1903 if(appData.debugMode)fprintf(debugFP,"SHOGI promoChar = %c\n", promoChar ? promoChar : '-');
1904 if(promoChar != NULLCHAR && promoChar != '+' && promoChar != '=')
1905 return CharToPiece(promoChar) == EmptySquare ? ImpossibleMove : IllegalMove;
1906 else if(flags & F_WHITE_ON_MOVE) {
1907 if( (int) piece < (int) WhiteWazir &&
1908 (rf >= BOARD_HEIGHT - zone || rt >= BOARD_HEIGHT - zone) ) {
1909 if( (piece == WhitePawn || piece == WhiteQueen) && rt > BOARD_HEIGHT-2 ||
1910 piece == WhiteKnight && rt > BOARD_HEIGHT-3) /* promotion mandatory */
1911 cl.kind = promoChar == '=' ? IllegalMove : WhitePromotion;
1912 else /* promotion optional, default is defer */
1913 cl.kind = promoChar == '+' ? WhitePromotion : WhiteNonPromotion;
1914 } else cl.kind = promoChar == '+' ? IllegalMove : NormalMove;
1916 if( (int) piece < (int) BlackWazir && (rf < zone || rt < zone) ) {
1917 if( (piece == BlackPawn || piece == BlackQueen) && rt < 1 ||
1918 piece == BlackKnight && rt < 2 ) /* promotion obligatory */
1919 cl.kind = promoChar == '=' ? IllegalMove : BlackPromotion;
1920 else /* promotion optional, default is defer */
1921 cl.kind = promoChar == '+' ? BlackPromotion : BlackNonPromotion;
1922 } else cl.kind = promoChar == '+' ? IllegalMove : NormalMove;
1926 if (promoChar != NULLCHAR) {
1927 if(cl.kind == NormalMove && promoChar == '+') { // allow shogi-style promotion is pieceToChar specifies them
1928 ChessSquare piece = board[rf][ff];
1929 if(piece < BlackPawn ? piece > WhiteMan : piece > BlackMan) return ImpossibleMove; // already promoted
1930 // should test if in zone, really
1931 if(gameInfo.variant == VariantChuChess && (piece == WhiteKnight || piece == BlackKnight) && HasLion(board, flags))
1933 if(PieceToChar(PROMOTED(piece)) == '+') return flags & F_WHITE_ON_MOVE ? WhitePromotion : BlackPromotion;
1935 if(promoChar == '=') cl.kind = IllegalMove; else // [HGM] shogi: no deferred promotion outside Shogi
1936 if (cl.kind == WhitePromotion || cl.kind == BlackPromotion) {
1937 ChessSquare piece = CharToPiece(flags & F_WHITE_ON_MOVE ? ToUpper(promoChar) : ToLower(promoChar));
1938 if(piece == EmptySquare)
1939 cl.kind = ImpossibleMove; // non-existing piece
1940 if(gameInfo.variant == VariantChuChess && promoChar == 'l' && HasLion(board, flags)) {
1941 cl.kind = IllegalMove; // no two Lions
1942 } else if(gameInfo.variant == VariantSpartan && cl.kind == BlackPromotion ) {
1943 if(promoChar != PieceToChar(BlackKing)) {
1944 if(CheckTest(board, flags, rf, ff, rt, ft, FALSE)) cl.kind = IllegalMove; // [HGM] spartan: only promotion to King was possible
1945 if(piece == BlackLance) cl.kind = ImpossibleMove;
1946 } else { // promotion to King allowed only if we do not have two yet
1947 int r, f, kings = 0;
1948 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++) kings += (board[r][f] == BlackKing);
1949 if(kings == 2) cl.kind = IllegalMove;
1951 } else if(piece == WhitePawn && rt == BOARD_HEIGHT-1 ||
1952 piece == BlackPawn && rt == 0) cl.kind = IllegalMove; // cannot stay Pawn on last rank in any variant
1953 else if((piece == WhiteUnicorn || piece == BlackUnicorn) && gameInfo.variant == VariantKnightmate)
1954 cl.kind = IllegalMove; // promotion to Royal Knight not allowed
1955 else if((piece == WhiteKing || piece == BlackKing) && gameInfo.variant != VariantSuicide && gameInfo.variant != VariantGiveaway)
1956 cl.kind = IllegalMove; // promotion to King usually not allowed
1958 cl.kind = IllegalMove;
1968 extern void MateTestCallback P((Board board, int flags, ChessMove kind,
1969 int rf, int ff, int rt, int ft,
1973 MateTestCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1975 register MateTestClosure *cl = (MateTestClosure *) closure;
1980 /* Return MT_NONE, MT_CHECK, MT_CHECKMATE, or MT_STALEMATE */
1982 MateTest (Board board, int flags)
1985 int inCheck, r, f, myPieces=0, hisPieces=0, nrKing=0;
1986 ChessSquare king = flags & F_WHITE_ON_MOVE ? WhiteKing : BlackKing;
1988 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++) {
1989 // [HGM] losers: Count pieces and kings, to detect other unorthodox winning conditions
1990 nrKing += (board[r][f] == king); // stm has king
1991 if( board[r][f] != EmptySquare ) {
1992 if((int)board[r][f] <= (int)king && (int)board[r][f] >= (int)king - (int)WhiteKing + (int)WhitePawn)
1997 switch(gameInfo.variant) { // [HGM] losers: extinction wins
1998 case VariantShatranj:
1999 if(hisPieces == 1) return myPieces > 1 ? MT_BARE : MT_DRAW;
2003 if(nrKing == 0) return MT_NOKING;
2006 if(myPieces == 1) return MT_BARE;
2009 inCheck = GenLegal(board, flags, MateTestCallback, (VOIDSTAR) &cl, EmptySquare);
2010 // [HGM] 3check: yet to do!
2012 return inCheck ? MT_CHECK : MT_NONE;
2014 if(gameInfo.holdingsWidth && gameInfo.variant != VariantSuper && gameInfo.variant != VariantGreat
2015 && gameInfo.variant != VariantSChess && gameInfo.variant != VariantGrand) { // drop game
2016 int r, f, n, holdings = flags & F_WHITE_ON_MOVE ? BOARD_WIDTH-1 : 0;
2017 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++) if(board[r][f] == EmptySquare) // all empty squares
2018 for(n=0; n<BOARD_HEIGHT; n++) // all pieces in hand
2019 if(board[n][holdings] != EmptySquare) {
2020 int moveType = LegalDrop(board, flags, board[n][holdings], r, f);
2021 if(moveType == WhiteDrop || moveType == BlackDrop) return (inCheck ? MT_CHECK : MT_NONE); // we have legal drop
2024 if(gameInfo.variant == VariantSuicide) // [HGM] losers: always stalemate, since no check, but result varies
2025 return myPieces == hisPieces ? MT_STALEMATE :
2026 myPieces > hisPieces ? MT_STAINMATE : MT_STEALMATE;
2027 else if(gameInfo.variant == VariantLosers) return inCheck ? MT_TRICKMATE : MT_STEALMATE;
2028 else if(gameInfo.variant == VariantGiveaway) return MT_STEALMATE; // no check exists, stalemated = win
2030 return inCheck ? MT_CHECKMATE
2031 : (gameInfo.variant == VariantXiangqi || gameInfo.variant == VariantShatranj || IS_SHOGI(gameInfo.variant)) ?
2032 MT_STAINMATE : MT_STALEMATE;
2037 extern void DisambiguateCallback P((Board board, int flags, ChessMove kind,
2038 int rf, int ff, int rt, int ft,
2042 DisambiguateCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
2044 register DisambiguateClosure *cl = (DisambiguateClosure *) closure;
2045 int wildCard = FALSE; ChessSquare piece = board[rf][ff];
2046 extern int kifu; // in parser.c
2048 // [HGM] wild: for wild-card pieces rt and rf are dummies
2049 if(piece == WhiteFalcon || piece == BlackFalcon ||
2050 piece == WhiteCobra || piece == BlackCobra)
2053 if ((cl->pieceIn == EmptySquare || cl->pieceIn == board[rf][ff]
2054 || PieceToChar(board[rf][ff]) == '~'
2055 && cl->pieceIn == (ChessSquare)(DEMOTED(board[rf][ff]))
2057 (cl->rfIn == -1 || cl->rfIn == rf) &&
2058 (cl->ffIn == -1 || cl->ffIn == ff) &&
2059 (cl->rtIn == -1 || cl->rtIn == rt || wildCard) &&
2060 (cl->ftIn == -1 || cl->ftIn == ft || wildCard)) {
2062 if(cl->count && rf == cl->rf && ff == cl->ff) return; // duplicate move
2064 if(cl->count == 1 && kifu & 0x7E && cl->rfIn == -1 && cl->ffIn == -1) { // traditional Shogi disambiguation required
2065 int this = 1, other = 1;
2066 if(kifu & 2) this &= (flags & 1 ? rt > rf : rt < rf), other &= (flags & 1 ? cl->rt > cl->rf : cl->rt < cl->rf);
2067 if(kifu & 4) this &= (flags & 1 ? rt < rf : rt > rf), other &= (flags & 1 ? cl->rt < cl->rf : cl->rt > cl->rf);
2068 if(kifu & 8) this &= (rf == rt), other &= (cl->rt == cl->rf);
2069 if(kifu & 0x10) this &= (flags & 1 ? ft <= ff : ft >= ff), other &= (flags & 1 ? cl->ft <= cl->ff : cl->ft >= cl->ff);
2070 if(kifu & 0x20) this &= (flags & 1 ? ft >= ff : ft <= ff), other &= (flags & 1 ? cl->ft >= cl->ff : cl->ft <= cl->ff);
2071 if(kifu & 0x40) this &= (ft == ff), other &= (cl->ft == cl->ff); // should never be used
2072 if(!other) cl->count--; // the old move did not satisfy the requested relative position, erase it
2073 if(!this) return; // the current move does not satisfy the requested relative position, ignore it
2077 if(cl->count == 1 || board[rt][ft] != EmptySquare) {
2078 // [HGM] oneclick: if multiple moves, be sure we remember capture
2079 cl->piece = board[rf][ff];
2082 cl->rt = wildCard ? cl->rtIn : rt;
2083 cl->ft = wildCard ? cl->ftIn : ft;
2086 cl->captures += (board[rt][ft] != EmptySquare); // [HGM] oneclick: count captures
2091 Disambiguate (Board board, int flags, DisambiguateClosure *closure)
2093 int illegal = 0; char c = closure->promoCharIn;
2095 if(quickFlag) flags = flags & ~1 | quickFlag & 1; // [HGM] speed: in quick mode quickFlag specifies side-to-move.
2096 closure->count = closure->captures = 0;
2097 closure->rf = closure->ff = closure->rt = closure->ft = 0;
2098 closure->kind = ImpossibleMove;
2099 rFilter = closure->rtIn; // [HGM] speed: only consider moves to given to-square
2100 fFilter = closure->ftIn;
2101 if(quickFlag) { // [HGM] speed: try without check test first, because if that is not ambiguous, we are happy
2102 GenLegal(board, flags|F_IGNORE_CHECK, DisambiguateCallback, (VOIDSTAR) closure, closure->pieceIn);
2103 if(closure->count > 1) { // gamble did not pay off. retry with check test to resolve ambiguity
2104 closure->count = closure->captures = 0;
2105 closure->rf = closure->ff = closure->rt = closure->ft = 0;
2106 closure->kind = ImpossibleMove;
2107 GenLegal(board, flags, DisambiguateCallback, (VOIDSTAR) closure, closure->pieceIn); // [HGM] speed: only pieces of requested type
2110 GenLegal(board, flags, DisambiguateCallback, (VOIDSTAR) closure, closure->pieceIn); // [HGM] speed: only pieces of requested type
2111 if (closure->count == 0) {
2112 /* See if it's an illegal move due to check */
2114 GenLegal(board, flags|F_IGNORE_CHECK, DisambiguateCallback, (VOIDSTAR) closure, closure->pieceIn);
2115 if (closure->count == 0) {
2116 /* No, it's not even that */
2117 if(!appData.testLegality && !pieceDefs && closure->pieceIn != EmptySquare) {
2118 int f, r; // if there is only a single piece of the requested type on the board, use that
2119 closure->rt = closure->rtIn, closure->ft = closure->ftIn;
2120 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++)
2121 if(board[r][f] == closure->pieceIn) closure->count++, closure->rf = r, closure->ff = f;
2122 if(closure->count > 1) illegal = 0; // ambiguous
2124 if(closure->count == 0) {
2125 if (appData.debugMode) { int i, j;
2126 for(i=BOARD_HEIGHT-1; i>=0; i--) {
2127 for(j=0; j<BOARD_WIDTH; j++)
2128 fprintf(debugFP, "%3d", (int) board[i][j]);
2129 fprintf(debugFP, "\n");
2135 } else if(pieceDefs && closure->count > 1) { // [HGM] gen: move is ambiguous under engine-defined rules
2136 DisambiguateClosure spare = *closure;
2137 pieceDefs = FALSE; spare.count = 0; // See if the (erroneous) built-in rules would resolve that
2138 GenLegal(board, flags, DisambiguateCallback, (VOIDSTAR) &spare, closure->pieceIn);
2139 if(spare.count == 1) *closure = spare; // It does, so use those in stead (game from file saved before gen patch?)
2143 if (c == 'x') c = NULLCHAR; // get rid of any 'x' (which should never happen?)
2144 if(gameInfo.variant == VariantSChess && c && c != '=' && closure->piece != WhitePawn && closure->piece != BlackPawn) {
2145 if(closure->piece < BlackPawn) { // white
2146 if(closure->rf != 0) closure->kind = IllegalMove; // must be on back rank
2147 if(!(board[VIRGIN][closure->ff] & VIRGIN_W)) closure->kind = IllegalMove; // non-virgin
2148 if(board[PieceToNumber(CharToPiece(ToUpper(c)))][BOARD_WIDTH-2] == 0) closure->kind = ImpossibleMove;// must be in stock
2149 if(closure->kind == WhiteHSideCastleFR && (closure->ff == BOARD_RGHT-2 || closure->ff == BOARD_RGHT-3)) closure->kind = ImpossibleMove;
2150 if(closure->kind == WhiteASideCastleFR && (closure->ff == BOARD_LEFT+2 || closure->ff == BOARD_LEFT+3)) closure->kind = ImpossibleMove;
2152 if(closure->rf != BOARD_HEIGHT-1) closure->kind = IllegalMove;
2153 if(!(board[VIRGIN][closure->ff] & VIRGIN_B)) closure->kind = IllegalMove; // non-virgin
2154 if(board[BOARD_HEIGHT-1-PieceToNumber(CharToPiece(ToLower(c)))][1] == 0) closure->kind = ImpossibleMove;
2155 if(closure->kind == BlackHSideCastleFR && (closure->ff == BOARD_RGHT-2 || closure->ff == BOARD_RGHT-3)) closure->kind = ImpossibleMove;
2156 if(closure->kind == BlackASideCastleFR && (closure->ff == BOARD_LEFT+2 || closure->ff == BOARD_LEFT+3)) closure->kind = ImpossibleMove;
2159 if(gameInfo.variant == VariantChu) {
2160 if(c == '+') closure->kind = (flags & F_WHITE_ON_MOVE ? WhitePromotion : BlackPromotion); // for now, accept any
2162 if(gameInfo.variant == VariantShogi) {
2163 /* [HGM] Shogi promotions. On input, '=' means defer, '+' promote. Afterwards, c is set to '+' for promotions, NULL other */
2164 if(closure->rfIn != DROP_RANK && closure->kind == NormalMove) {
2165 ChessSquare piece = closure->piece;
2166 int zone = BOARD_HEIGHT/3 + (BOARD_HEIGHT == 8);
2167 if (c == 'd' && (piece == WhiteRook || piece == BlackRook) ||
2168 c == 'h' && (piece == WhiteBishop || piece == BlackBishop) ||
2169 c == 'g' && (piece <= WhiteFerz || piece <= BlackFerz && piece >= BlackPawn) )
2170 c = '+'; // allowed ICS notations
2171 if(c != NULLCHAR && c != '+' && c != '=') closure->kind = IllegalMove; // otherwise specifying a piece is illegal
2172 else if(flags & F_WHITE_ON_MOVE) {
2173 if( (int) piece < (int) WhiteWazir &&
2174 (closure->rf >= BOARD_HEIGHT-zone || closure->rt >= BOARD_HEIGHT-zone) ) {
2175 if( (piece == WhitePawn || piece == WhiteQueen) && closure->rt > BOARD_HEIGHT-2 ||
2176 piece == WhiteKnight && closure->rt > BOARD_HEIGHT-3) /* promotion mandatory */
2177 closure->kind = c == '=' ? IllegalMove : WhitePromotion;
2178 else /* promotion optional, default is defer */
2179 closure->kind = c == '+' ? WhitePromotion : WhiteNonPromotion;
2180 } else closure->kind = c == '+' ? IllegalMove : NormalMove;
2182 if( (int) piece < (int) BlackWazir && (closure->rf < zone || closure->rt < zone) ) {
2183 if( (piece == BlackPawn || piece == BlackQueen) && closure->rt < 1 ||
2184 piece == BlackKnight && closure->rt < 2 ) /* promotion obligatory */
2185 closure->kind = c == '=' ? IllegalMove : BlackPromotion;
2186 else /* promotion optional, default is defer */
2187 closure->kind = c == '+' ? BlackPromotion : BlackNonPromotion;
2188 } else closure->kind = c == '+' ? IllegalMove : NormalMove;
2191 if(closure->kind == WhitePromotion || closure->kind == BlackPromotion) c = '+'; else
2192 if(closure->kind == WhiteNonPromotion || closure->kind == BlackNonPromotion) c = '=';
2194 if (closure->kind == WhitePromotion || closure->kind == BlackPromotion) {
2195 if(c == NULLCHAR) { // missing promoChar on mandatory promotion; use default for variant
2196 if(gameInfo.variant == VariantShatranj || gameInfo.variant == VariantCourier ||
2197 gameInfo.variant == VariantMakruk)
2198 c = PieceToChar(BlackFerz);
2199 else if(gameInfo.variant == VariantASEAN)
2200 c = PieceToChar(BlackRook);
2201 else if(gameInfo.variant == VariantGreat)
2202 c = PieceToChar(BlackMan);
2203 else if(gameInfo.variant == VariantGrand)
2204 closure->kind = closure->rt != 0 && closure->rt != BOARD_HEIGHT-1 ? NormalMove : AmbiguousMove; // no default in Grand Chess
2206 c = PieceToChar(BlackQueen);
2207 } else if(c == '=') closure->kind = IllegalMove; // no deferral outside Shogi
2208 else if(c == 'l' && gameInfo.variant == VariantChuChess && HasLion(board, flags)) closure->kind = IllegalMove;
2209 } else if (c == '+') { // '+' outside shogi, check if pieceToCharTable enabled it
2210 ChessSquare p = closure->piece;
2211 if(p > WhiteMan && p < BlackPawn || p > BlackMan || PieceToChar(PROMOTED(p)) != '+')
2212 closure->kind = ImpossibleMove; // used on non-promotable piece
2213 else if(gameInfo.variant == VariantChuChess && HasLion(board, flags)) closure->kind = IllegalMove;
2214 } else if (c != NULLCHAR) closure->kind = IllegalMove;
2216 closure->promoChar = ToLower(c); // this can be NULLCHAR! Note we keep original promoChar even if illegal.
2217 if(c != '+' && c != '=' && c != NULLCHAR && CharToPiece(flags & F_WHITE_ON_MOVE ? ToUpper(c) : ToLower(c)) == EmptySquare)
2218 closure->kind = ImpossibleMove; // but we cannot handle non-existing piece types!
2219 if (closure->count > 1) {
2220 closure->kind = AmbiguousMove;
2223 /* Note: If more than one illegal move matches, but no legal
2224 moves, we return IllegalMove, not AmbiguousMove. Caller
2225 can look at closure->count to detect this.
2227 closure->kind = IllegalMove;
2241 } CoordsToAlgebraicClosure;
2243 extern void CoordsToAlgebraicCallback P((Board board, int flags,
2244 ChessMove kind, int rf, int ff,
2245 int rt, int ft, VOIDSTAR closure));
2248 CoordsToAlgebraicCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
2250 register CoordsToAlgebraicClosure *cl =
2251 (CoordsToAlgebraicClosure *) closure;
2253 if ((rt == cl->rt && ft == cl->ft || rt == rf && ft == ff) && // [HGM] null move matches any toSquare
2254 (board[rf][ff] == cl->piece
2255 || PieceToChar(board[rf][ff]) == '~' &&
2256 (ChessSquare) (DEMOTED(board[rf][ff])) == cl->piece)
2260 cl->kind = kind; /* this is the move we want */
2262 cl->file++; /* need file to rule out this move */
2266 cl->rank++; /* need rank to rule out this move */
2268 cl->either++; /* rank or file will rule out this move */
2274 /* Convert coordinates to normal algebraic notation.
2275 promoChar must be NULLCHAR or 'x' if not a promotion.
2278 CoordsToAlgebraic (Board board, int flags, int rf, int ff, int rt, int ft, int promoChar, char out[MOVE_LEN])
2282 char *outp = out, c, capture;
2283 CoordsToAlgebraicClosure cl;
2285 if (rf == DROP_RANK) {
2286 if(ff == EmptySquare) { strncpy(outp, "--",3); return NormalMove; } // [HGM] pass
2287 /* Bughouse piece drop */
2288 *outp++ = ToUpper(PieceToChar((ChessSquare) ff));
2293 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2295 return (flags & F_WHITE_ON_MOVE) ? WhiteDrop : BlackDrop;
2298 if (promoChar == 'x') promoChar = NULLCHAR;
2299 piece = board[rf][ff];
2300 if(PieceToChar(piece)=='~') piece = (ChessSquare)(DEMOTED(piece));
2305 kind = LegalityTest(board, flags, rf, ff, rt, ft, promoChar);
2306 if (kind == IllegalMove && !(flags&F_IGNORE_CHECK)) {
2307 /* Keep short notation if move is illegal only because it
2308 leaves the player in check, but still return IllegalMove */
2309 kind = LegalityTest(board, flags|F_IGNORE_CHECK, rf, ff, rt, ft, promoChar);
2310 if (kind == IllegalMove) break;
2315 capture = board[rt][ft] != EmptySquare || kind == WhiteCapturesEnPassant || kind == BlackCapturesEnPassant;
2316 if (ff == ft && !capture) { /* [HGM] Xiangqi has straight noncapts! */
2317 /* Non-capture; use style "e5" */
2320 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2322 /* Capture; use style "exd5" */
2324 *outp++ = 'x'; /* [HGM] Xiangqi has sideway noncaptures across river! */
2328 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2330 /* Use promotion suffix style "=Q" */
2332 if (promoChar != NULLCHAR) {
2333 if(IS_SHOGI(gameInfo.variant)) {
2334 /* [HGM] ... but not in Shogi! */
2335 *outp++ = promoChar == '=' ? '=' : '+';
2338 *outp++ = ToUpper(promoChar);
2347 /* Fabien moved code: FRC castling first (if KxR), wild castling second */
2348 /* Code added by Tord: FRC castling. */
2349 if((piece == WhiteKing && board[rt][ft] == WhiteRook) ||
2350 (piece == BlackKing && board[rt][ft] == BlackRook)) {
2352 safeStrCpy(out, "O-O", MOVE_LEN);
2354 safeStrCpy(out, "O-O-O", MOVE_LEN);
2355 return LegalityTest(board, flags, rf, ff, rt, ft, promoChar);
2357 /* End of code added by Tord */
2358 /* Test for castling or ICS wild castling */
2359 /* Use style "O-O" (oh-oh) for PGN compatibility */
2360 else if (rf == rt &&
2361 rf == ((piece == WhiteKing) ? 0 : BOARD_HEIGHT-1) &&
2362 (ft - ff > 1 || ff - ft > 1) && // No castling if legal King move (on narrow boards!)
2363 ((ff == BOARD_WIDTH>>1 && (ft == BOARD_LEFT+2 || ft == BOARD_RGHT-2)) ||
2364 (ff == (BOARD_WIDTH-1)>>1 && (ft == BOARD_LEFT+1 || ft == BOARD_RGHT-3)))) {
2365 if(ft==BOARD_LEFT+1 || ft==BOARD_RGHT-2)
2366 snprintf(out, MOVE_LEN, "O-O%c%c", promoChar ? '/' : 0, ToUpper(promoChar));
2368 snprintf(out, MOVE_LEN, "O-O-O%c%c", promoChar ? '/' : 0, ToUpper(promoChar));
2370 /* This notation is always unambiguous, unless there are
2371 kings on both the d and e files, with "wild castling"
2372 possible for the king on the d file and normal castling
2373 possible for the other. ICS rules for wild 9
2374 effectively make castling illegal for either king in
2375 this situation. So I am not going to worry about it;
2376 I'll just generate an ambiguous O-O in this case.
2378 return LegalityTest(board, flags, rf, ff, rt, ft, promoChar);
2381 /* else fall through */
2386 cl.rt = rFilter = rt; // [HGM] speed: filter on to-square
2387 cl.ft = fFilter = ft;
2389 cl.kind = IllegalMove;
2390 cl.rank = cl.file = cl.either = 0;
2391 c = PieceToChar(piece) ;
2392 GenLegal(board, flags, CoordsToAlgebraicCallback, (VOIDSTAR) &cl, c!='~' ? piece : (DEMOTED(piece))); // [HGM] speed
2394 if (cl.kind == IllegalMove && !(flags&F_IGNORE_CHECK)) {
2395 /* Generate pretty moves for moving into check, but
2396 still return IllegalMove.
2398 GenLegal(board, flags|F_IGNORE_CHECK, CoordsToAlgebraicCallback, (VOIDSTAR) &cl, c!='~' ? piece : (DEMOTED(piece)));
2399 if (cl.kind == IllegalMove) break;
2400 cl.kind = IllegalMove;
2403 /* Style is "Nf3" or "Nxf7" if this is unambiguous,
2404 else "Ngf3" or "Ngxf7",
2405 else "N1f3" or "N5xf7",
2406 else "Ng1f3" or "Ng5xf7".
2408 if( c == '~' || c == '+') {
2409 /* [HGM] print nonexistent piece as its demoted version */
2410 piece = (ChessSquare) (CHUDEMOTED(piece));
2412 if(c=='+') *outp++ = c;
2413 *outp++ = ToUpper(PieceToChar(piece));
2414 if(*outp = PieceSuffix(piece)) outp++;
2416 if (cl.file || (cl.either && !cl.rank)) {
2422 else { *outp++ = (rf+ONE-'0')/10 + '0';*outp++ = (rf+ONE-'0')%10 + '0'; }
2425 if(board[rt][ft] != EmptySquare)
2431 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2432 if (IS_SHOGI(gameInfo.variant)) {
2433 /* [HGM] in Shogi non-pawns can promote */
2434 *outp++ = promoChar; // Don't bother to correct move type, return value is never used!
2436 else if (gameInfo.variant == VariantChuChess && promoChar ||
2437 gameInfo.variant != VariantSuper && promoChar &&
2438 (piece == WhiteLance || piece == BlackLance) ) { // Lance sometimes represents Pawn
2440 *outp++ = ToUpper(promoChar);
2442 else if (gameInfo.variant == VariantSChess && promoChar) { // and in S-Chess we have gating
2444 *outp++ = ToUpper(promoChar);
2450 /* Moving a nonexistent piece */
2454 /* Not a legal move, even ignoring check.
2455 If there was a piece on the from square,
2456 use style "Ng1g3" or "Ng1xe8";
2457 if there was a pawn or nothing (!),
2458 use style "g1g3" or "g1xe8". Use "x"
2459 if a piece was on the to square, even
2460 a piece of the same color.
2464 if (piece != EmptySquare && piece != WhitePawn && piece != BlackPawn) {
2466 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<=BOARD_RGHT; f++)
2467 c += (board[r][f] == piece); // count on-board pieces of given type
2468 *outp = PieceToChar(piece);
2469 if(*outp == '+') outp++, piece = CHUDEMOTED(piece);
2470 *outp++ = ToUpper(PieceToChar(piece));
2471 if(*outp = PieceSuffix(piece)) outp++;
2473 if(c != 1) { // [HGM] but if there is only one piece of the mentioned type, no from-square, thank you!
2477 else { *outp++ = (rf+ONE-'0')/10 + '0';*outp++ = (rf+ONE-'0')%10 + '0'; }
2479 if (board[rt][ft] != EmptySquare) *outp++ = 'x';
2483 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2484 /* Use promotion suffix style "=Q" */
2485 if (promoChar != NULLCHAR && promoChar != 'x') {
2487 *outp++ = ToUpper(promoChar);
2494 // [HGM] XQ: the following code serves to detect perpetual chasing (Asian rules)
2503 // I guess the following variables logically belong in the closure too, but I was too lazy and used globals
2505 int preyStackPointer, chaseStackPointer;
2508 unsigned char rf, ff, rt, ft;
2512 unsigned char rank, file;
2518 // there are three new callbacks for use with GenLegal: for adding captures, deleting them, and finding a recapture
2520 extern void AtacksCallback P((Board board, int flags, ChessMove kind,
2521 int rf, int ff, int rt, int ft,
2525 AttacksCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
2526 { // For adding captures that can lead to chase indictment to the chaseStack
2527 if(board[rt][ft] == EmptySquare) return; // non-capture
2528 if(board[rt][ft] == WhitePawn && rt < BOARD_HEIGHT/2) return; // Pawn before river can be chased
2529 if(board[rt][ft] == BlackPawn && rt >= BOARD_HEIGHT/2) return; // Pawn before river can be chased
2530 if(board[rf][ff] == WhitePawn || board[rf][ff] == BlackPawn) return; // Pawns are allowed to chase
2531 if(board[rf][ff] == WhiteWazir || board[rf][ff] == BlackWazir) return; // King is allowed to chase
2532 // move cannot be excluded from being a chase trivially (based on attacker and victim); save it on chaseStack
2533 chaseStack[chaseStackPointer].rf = rf;
2534 chaseStack[chaseStackPointer].ff = ff;
2535 chaseStack[chaseStackPointer].rt = rt;
2536 chaseStack[chaseStackPointer].ft = ft;
2537 chaseStackPointer++;
2540 extern void ExistingAtacksCallback P((Board board, int flags, ChessMove kind,
2541 int rf, int ff, int rt, int ft,
2545 ExistingAttacksCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
2546 { // for removing pre-exsting captures from the chaseStack, to be left with newly created ones
2548 register ChaseClosure *cl = (ChaseClosure *) closure; //closure tells us the move played in the repeat loop
2550 if(board[rt][ft] == EmptySquare) return; // no capture
2551 if(rf == cl->rf && ff == cl->ff) { // attacks with same piece from new position are not considered new
2552 rf = cl->rt; ff = cl->ft; // doctor their fromSquare so they will be recognized in chaseStack
2554 // search move in chaseStack, and delete it if it occurred there (as we know now it is not a new capture)
2555 for(i=0; i<chaseStackPointer; i++) {
2556 if(chaseStack[i].rf == rf && chaseStack[i].ff == ff &&
2557 chaseStack[i].rt == rt && chaseStack[i].ft == ft ) {
2558 // move found on chaseStack, delete it by overwriting with move popped from top of chaseStack
2559 chaseStack[i] = chaseStack[--chaseStackPointer];
2565 extern void ProtectedCallback P((Board board, int flags, ChessMove kind,
2566 int rf, int ff, int rt, int ft,
2570 ProtectedCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
2571 { // for determining if a piece (given through the closure) is protected
2572 register ChaseClosure *cl = (ChaseClosure *) closure; // closure tells us where to recapture
2574 if(rt == cl->rt && ft == cl->ft) cl->recaptures++; // count legal recaptures to this square
2575 if(appData.debugMode && board[rt][ft] != EmptySquare)
2576 fprintf(debugFP, "try %c%c%c%c=%d\n", ff+AAA, rf+ONE,ft+AAA, rt+ONE, cl->recaptures);
2579 extern char moveList[MAX_MOVES][MOVE_LEN];
2582 PerpetualChase (int first, int last)
2583 { // this routine detects if the side to move in the 'first' position is perpetually chasing (when not checking)
2586 ChessSquare captured;
2588 preyStackPointer = 0; // clear stack of chased pieces
2589 for(i=first; i<last; i+=2) { // for all positions with same side to move
2590 if(appData.debugMode) fprintf(debugFP, "judge position %i\n", i);
2591 chaseStackPointer = 0; // clear stack that is going to hold possible chases
2592 // determine all captures possible after the move, and put them on chaseStack
2593 GenLegal(boards[i+1], PosFlags(i), AttacksCallback, &cl, EmptySquare);
2594 if(appData.debugMode) { int n;
2595 for(n=0; n<chaseStackPointer; n++)
2596 fprintf(debugFP, "%c%c%c%c ", chaseStack[n].ff+AAA, chaseStack[n].rf+ONE,
2597 chaseStack[n].ft+AAA, chaseStack[n].rt+ONE);
2598 fprintf(debugFP, ": all capts\n");
2600 // determine all captures possible before the move, and delete them from chaseStack
2601 cl.rf = moveList[i][1]-ONE; // prepare closure to pass move that led from i to i+1
2602 cl.ff = moveList[i][0]-AAA+BOARD_LEFT;
2603 cl.rt = moveList[i][3]-ONE;
2604 cl.ft = moveList[i][2]-AAA+BOARD_LEFT;
2605 CopyBoard(xqCheckers, nullBoard); xqCheckers[EP_STATUS] = 1; // giant kludge to make GenLegal ignore pre-existing checks
2606 GenLegal(boards[i], PosFlags(i), ExistingAttacksCallback, &cl, EmptySquare);
2607 xqCheckers[EP_STATUS] = 0; // disable the generation of quasi-legal moves again
2608 if(appData.debugMode) { int n;
2609 for(n=0; n<chaseStackPointer; n++)
2610 fprintf(debugFP, "%c%c%c%c ", chaseStack[n].ff+AAA, chaseStack[n].rf+ONE,
2611 chaseStack[n].ft+AAA, chaseStack[n].rt+ONE);
2612 fprintf(debugFP, ": new capts after %c%c%c%c\n", cl.ff+AAA, cl.rf+ONE, cl.ft+AAA, cl.rt+ONE);
2614 // chaseSack now contains all captures made possible by the move
2615 for(j=0; j<chaseStackPointer; j++) { // run through chaseStack to identify true chases
2616 int attacker = (int)boards[i+1][chaseStack[j].rf][chaseStack[j].ff];
2617 int victim = (int)boards[i+1][chaseStack[j].rt][chaseStack[j].ft];
2619 if(attacker >= (int) BlackPawn) attacker = BLACK_TO_WHITE attacker; // convert to white, as piecee type
2620 if(victim >= (int) BlackPawn) victim = BLACK_TO_WHITE victim;
2622 if((attacker == WhiteKnight || attacker == WhiteCannon) && victim == WhiteRook)
2623 continue; // C or H attack on R is always chase; leave on chaseStack
2625 if(attacker == victim) {
2626 if(LegalityTest(boards[i+1], PosFlags(i+1), chaseStack[j].rt,
2627 chaseStack[j].ft, chaseStack[j].rf, chaseStack[j].ff, NULLCHAR) == NormalMove) {
2628 // we can capture back with equal piece, so this is no chase but a sacrifice
2629 chaseStack[j] = chaseStack[--chaseStackPointer]; // delete the capture from the chaseStack
2630 j--; /* ! */ continue;
2635 // the attack is on a lower piece, or on a pinned or blocked equal one
2636 CopyBoard(xqCheckers, nullBoard); xqCheckers[EP_STATUS] = 1;
2637 CheckTest(boards[i+1], PosFlags(i+1), -1, -1, -1, -1, FALSE); // if we deliver check with our move, the checkers get marked
2638 // test if the victim is protected by a true protector. First make the capture.
2639 captured = boards[i+1][chaseStack[j].rt][chaseStack[j].ft];
2640 boards[i+1][chaseStack[j].rt][chaseStack[j].ft] = boards[i+1][chaseStack[j].rf][chaseStack[j].ff];
2641 boards[i+1][chaseStack[j].rf][chaseStack[j].ff] = EmptySquare;
2642 // Then test if the opponent can recapture
2643 cl.recaptures = 0; // prepare closure to pass recapture square and count moves to it
2644 cl.rt = chaseStack[j].rt;
2645 cl.ft = chaseStack[j].ft;
2646 if(appData.debugMode) {
2647 fprintf(debugFP, "test if we can recapture %c%c\n", cl.ft+AAA, cl.rt+ONE);
2649 xqCheckers[EP_STATUS] = 2; // causes GenLegal to ignore the checks we delivered with the move, in real life evaded before we captured
2650 GenLegal(boards[i+1], PosFlags(i+1), ProtectedCallback, &cl, EmptySquare); // try all moves
2651 xqCheckers[EP_STATUS] = 0; // disable quasi-legal moves again
2652 // unmake the capture
2653 boards[i+1][chaseStack[j].rf][chaseStack[j].ff] = boards[i+1][chaseStack[j].rt][chaseStack[j].ft];
2654 boards[i+1][chaseStack[j].rt][chaseStack[j].ft] = captured;
2655 // if a recapture was found, piece is protected, and we are not chasing it.
2656 if(cl.recaptures) { // attacked piece was defended by true protector, no chase
2657 chaseStack[j] = chaseStack[--chaseStackPointer]; // so delete from chaseStack
2661 // chaseStack now contains all moves that chased
2662 if(appData.debugMode) { int n;
2663 for(n=0; n<chaseStackPointer; n++)
2664 fprintf(debugFP, "%c%c%c%c ", chaseStack[n].ff+AAA, chaseStack[n].rf+ONE,
2665 chaseStack[n].ft+AAA, chaseStack[n].rt+ONE);
2666 fprintf(debugFP, ": chases\n");
2668 if(i == first) { // copy all people chased by first move of repeat cycle to preyStack
2669 for(j=0; j<chaseStackPointer; j++) {
2670 preyStack[j].rank = chaseStack[j].rt;
2671 preyStack[j].file = chaseStack[j].ft;
2673 preyStackPointer = chaseStackPointer;
2676 for(j=0; j<chaseStackPointer; j++) {
2677 for(k=0; k<preyStackPointer; k++) {
2678 // search the victim of each chase move on the preyStack (first occurrence)
2679 if(chaseStack[j].ft == preyStack[k].file && chaseStack[j].rt == preyStack[k].rank ) {
2680 if(k < tail) break; // piece was already identified as still being chased
2681 preyStack[preyStackPointer] = preyStack[tail]; // move chased piece to bottom part of preyStack
2682 preyStack[tail] = preyStack[k]; // by swapping
2683 preyStack[k] = preyStack[preyStackPointer];
2689 preyStackPointer = tail; // keep bottom part of preyStack, popping pieces unchased on move i.
2690 if(appData.debugMode) { int n;
2691 for(n=0; n<preyStackPointer; n++)
2692 fprintf(debugFP, "%c%c ", preyStack[n].file+AAA, preyStack[n].rank+ONE);
2693 fprintf(debugFP, "always chased upto ply %d\n", i);
2695 // now adjust the location of the chased pieces according to opponent move
2696 for(j=0; j<preyStackPointer; j++) {
2697 if(preyStack[j].rank == moveList[i+1][1]-ONE &&
2698 preyStack[j].file == moveList[i+1][0]-AAA+BOARD_LEFT) {
2699 preyStack[j].rank = moveList[i+1][3]-ONE;
2700 preyStack[j].file = moveList[i+1][2]-AAA+BOARD_LEFT;
2705 return preyStackPointer ? 256*(preyStack[preyStackPointer].file - BOARD_LEFT + AAA) + (preyStack[preyStackPointer].rank + ONE)
2706 : 0; // if any piece was left on preyStack, it has been perpetually chased,and we return the