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);
75 extern signed char initialRights[BOARD_FILES]; /* [HGM] all rights enabled, set in InitPosition */
77 char *pieceDesc[EmptySquare];
78 char *defaultDesc[EmptySquare] = {
79 "fmWfceFifmnD", "N", "B", "R", "Q",
80 "F", "A", "BN", "RN", "W", "K",
81 "mRcpR", "N0", "BW", "RF", "gQ",
82 "", "", "QN", "", "N", "",
84 "", "", "", "", "", "",
86 "", "", "", "", "", "K"
90 WhitePiece (ChessSquare piece)
92 return (int) piece >= (int) WhitePawn && (int) piece < (int) BlackPawn;
96 BlackPiece (ChessSquare piece)
98 return (int) piece >= (int) BlackPawn && (int) piece < (int) EmptySquare;
103 SameColor (ChessSquare piece1, ChessSquare piece2)
105 return ((int) piece1 >= (int) WhitePawn && /* [HGM] can be > King ! */
106 (int) piece1 < (int) BlackPawn &&
107 (int) piece2 >= (int) WhitePawn &&
108 (int) piece2 < (int) BlackPawn)
109 || ((int) piece1 >= (int) BlackPawn &&
110 (int) piece1 < (int) EmptySquare &&
111 (int) piece2 >= (int) BlackPawn &&
112 (int) piece2 < (int) EmptySquare);
115 #define SameColor(piece1, piece2) (piece1 < EmptySquare && piece2 < EmptySquare && (piece1 < BlackPawn) == (piece2 < BlackPawn) || piece1 == DarkSquare || piece2 == DarkSquare)
118 unsigned char pieceToChar[EmptySquare+1] = {
119 'P', 'N', 'B', 'R', 'Q', 'F', 'E', 'A', 'C', 'W', 'M',
120 'O', 'H', 'I', 'J', 'G', 'D', 'V', 'L', 'S', 'U', 'K',
121 'p', 'n', 'b', 'r', 'q', 'f', 'e', 'a', 'c', 'w', 'm',
122 'o', 'h', 'i', 'j', 'g', 'd', 'v', 'l', 's', 'u', 'k',
124 unsigned char pieceNickName[EmptySquare];
127 PieceToChar (ChessSquare p)
130 if((int)p < 0 || (int)p >= (int)EmptySquare) return('x'); /* [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];
209 char *m, c, d, *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] == toupper(c)
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(toupper(d)) != 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];
229 snprintf(buf+len, MSG_SIZ-len, "%s%s%c:%s", len ? ";" : "", c == '+' ? "+" : "", d, m);
234 // [HGM] gen: configurable move generation from Betza notation sent by engine.
235 // Some notes about two-leg moves: GenPseudoLegal() works in two modes, depending on whether a 'kill-
236 // square has been set: without one is generates all moves, and a global int legNr flags in bits 0 and 1
237 // if the move has 1 or 2 legs. Only the marking of squares makes use of this info, by only marking
238 // target squares of leg 1 (rejecting null move). A dummy move with MoveType 'FirstLeg' to the relay square
239 // is generated, so a cyan marker can be put there, and other functions can ignore such a move. When the
240 // user selects this square, it becomes the kill-square. Once a kill-square is set, only 2-leg moves are
241 // generated that use that square as relay, plus 1-leg moves, so the 1-leg move that goes to the kill-square
242 // can be marked during 2nd-leg entry to terminate the move there. For judging the pseudo-legality of the
243 // 2nd leg, the from-square has to be considered empty, although the moving piece is still on it.
247 // alphabet "abcdefghijklmnopqrstuvwxyz"
248 char symmetry[] = "FBNW.FFW.NKN.NW.QR....W..N";
249 char xStep[] = "2110.130.102.10.00....0..2";
250 char yStep[] = "2132.133.313.20.11....1..3";
251 char dirType[] = "01000104000200000260050000";
252 char upgrade[] = "AFCD.BGH.JQL.NO.KW....R..Z";
253 char rotate[] = "DRCA.WHG.JKL.NO.QB....F..Z";
255 // 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 "
256 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 };
257 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 };
258 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 };
259 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 };
261 int rot[][4] = { // rotation matrices for each direction
273 OK (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR cl)
279 MovesFromString (Board board, int flags, int f, int r, int tx, int ty, int angle, char *desc, MoveCallback cb, VOIDSTAR cl)
281 char buf[80], *p = desc, *atom = NULL;
282 int mine, his, dir, bit, occup, i, ep, promoRank = -1;
283 ChessMove promo= NormalMove; ChessSquare pc = board[r][f];
284 if(pc == DarkSquare) return; // this is not a piece, but a 'hole' in the board
285 if(flags & F_WHITE_ON_MOVE) his = 2, mine = 1; else his = 1, mine = 2;
286 if(pc == WhitePawn || pc == WhiteLance) promo = WhitePromotion, promoRank = BOARD_HEIGHT-1; else
287 if(pc == BlackPawn || pc == BlackLance) promo = BlackPromotion, promoRank = 0;
288 while(*p) { // more moves to go
289 int expo = 1, dx, dy, x, y, mode, dirSet, ds2=0, retry=0, initial=0, jump=1, skip = 0, all = 0;
291 if(*p == 'i') initial = 1, desc = ++p;
292 while(islower(*p)) p++; // skip prefixes
293 if(!isupper(*p)) return; // syntax error: no atom
294 dx = xStep[*p-'A'] - '0';// step vector of atom
295 dy = yStep[*p-'A'] - '0';
296 dirSet = 0; // build direction set based on atom symmetry
297 switch(symmetry[*p-'A']) {
298 case 'B': expo = 0; // bishop, slide
299 case 'F': all = 0xAA; // diagonal atom (degenerate 4-fold)
300 if(tx >= 0) goto king; // continuation legs specified in K/Q system!
301 while(islower(*desc) && (i = dirType[*desc-'a']) != '0') {
302 int b = dirs1[*desc-'a']; // use wide version
303 if( islower(desc[1]) &&
304 ((i | dirType[desc[1]-'a']) & 3) == 3) { // combinable (perpendicular dim)
305 b = dirs1[*desc-'a'] & dirs1[desc[1]-'a']; // intersect wide & perp wide
310 dirSet &= 0xAA; if(!dirSet) dirSet = 0xAA;
312 case 'R': expo = 0; // rook, slide
313 case 'W': all = 0x55; // orthogonal atom (non-deg 4-fold)
314 if(tx >= 0) goto king; // continuation legs specified in K/Q system!
315 while(islower(*desc) && (dirType[*desc-'a'] & ~4) != '0') dirSet |= dirs2[*desc++-'a'];
316 dirSet &= 0x55; if(!dirSet) dirSet = 0x55;
317 dirSet = (dirSet << angle | dirSet >> 8-angle) & 255; // re-orient direction system
319 case 'N': all = 0xFF; // oblique atom (degenerate 8-fold)
320 if(tx >= 0) goto king; // continuation legs specified in K/Q system!
321 if(*desc == 'h') { // chiral direction sets 'hr' and 'hl'
322 dirSet = (desc[1] == 'r' ? 0x55 : 0xAA); desc += 2;
324 while(islower(*desc) && (i = dirType[*desc-'a']) != '0') {
325 int b = dirs2[*desc-'a']; // when alone, use narrow version
326 if(desc[1] == 'h') b = dirs1[*desc-'a'], desc += 2; // dirs1 is wide version
327 else if(*desc == desc[1] || islower(desc[1]) && i < '4'
328 && ((i | dirType[desc[1]-'a']) & 3) == 3) { // combinable (perpendicular dim or same)
329 b = dirs1[*desc-'a'] & dirs2[desc[1]-'a']; // intersect wide & perp narrow
334 if(!dirSet) dirSet = 0xFF;
336 case 'Q': expo = 0; // queen, slide
337 case 'K': all = 0xFF; // non-deg (pseudo) 8-fold
339 while(islower(*desc) && (i = dirType[*desc-'a']) != '0') {
340 int b = dirs4[*desc-'a']; // when alone, use narrow version
341 if(desc[1] == *desc) desc++; // doubling forces alone
342 else if(islower(desc[1]) && i < '4'
343 && ((i | dirType[desc[1]-'a']) & 3) == 3) { // combinable (perpendicular dim or same)
344 b = dirs3[*desc-'a'] & dirs3[desc[1]-'a']; // intersect wide & perp wide
349 if(!dirSet) dirSet = (tx < 0 ? 0xFF // default is all directions, but in continuation leg
350 : all == 0xFF ? 0xEF : 0x45); // omits backward, and for 4-fold atoms also diags
351 dirSet = (dirSet << angle | dirSet >> 8-angle) & 255; // re-orient direction system
352 ds2 = dirSet & 0xAA; // extract diagonal directions
353 if(dirSet &= 0x55) // start with orthogonal moves, if present
354 retry = 1, dx = 0; // and schedule the diagonal moves for later
355 else dx = dy, dirSet = ds2; // if no orthogonal directions, do diagonal immediately
356 break; // should not have direction indicators
357 default: return; // syntax error: invalid atom
359 if(mine == 2 && tx < 0) dirSet = dirSet >> 4 | dirSet << 4 & 255; // invert black moves
360 mode = 0; // build mode mask
361 if(*desc == 'm') mode |= 4, desc++; // move to empty
362 if(*desc == 'c') mode |= his, desc++; // capture foe
363 if(*desc == 'd') mode |= mine, desc++; // destroy (capture friend)
364 if(*desc == 'e') mode |= 8, desc++; // e.p. capture last mover
365 if(*desc == 't') mode |= 16, desc++; // exclude enemies as hop platform ('test')
366 if(*desc == 'p') mode |= 32, desc++; // hop over occupied
367 if(*desc == 'g') mode |= 64, desc++; // hop and toggle range
368 if(*desc == 'o') mode |= 128, desc++; // wrap around cylinder board
369 if(*desc == 'y') mode |= 512, desc++; // toggle range on empty square
370 if(*desc == 'n') jump = 0, desc++; // non-jumping
371 while(*desc == 'j') jump++, desc++; // must jump (on B,R,Q: skip first square)
372 if(*desc == 'a') cont = ++desc; // move again after doing what preceded it
373 if(isdigit(*++p)) expo = atoi(p++); // read exponent
374 if(expo > 9) p++; // allow double-digit
375 desc = p; // this is start of next move
376 if(initial && (board[r][f] != initialPosition[r][f] ||
377 r == 0 && board[TOUCHED_W] & 1<<f ||
378 r == BOARD_HEIGHT-1 && board[TOUCHED_B] & 1<<f ) ) continue;
379 if(expo > 1 && dx == 0 && dy == 0) { // castling indicated by O + number
380 mode |= 1024; dy = 1;
383 if(!(mode & 15)) mode |= his + 4; // no mode spec, use default = mc
385 strncpy(buf, cont, 80); cont = buf; // copy next leg(s), so we can modify
386 atom = buf; while(islower(*atom)) atom++; // skip to atom
387 if(mode & 32) mode ^= 256 + 32; // in non-final legs 'p' means 'pass through'
388 if(mode & 64 + 512) {
389 mode |= 256; // and 'g' too, but converts leaper <-> slider
390 if(mode & 512) mode ^= 0x304; // and 'y' is m-like 'g'
391 *atom = upgrade[*atom-'A']; // replace atom, BRQ <-> FWK
392 atom[1] = atom[2] = '\0'; // make sure any old range is stripped off
393 if(expo == 1) atom[1] = '0'; // turn other leapers into riders
395 if(!(mode & 0x30F)) mode |= 4; // and default of this leg = m
397 if(dy == 1) skip = jump - 1, jump = 1; // on W & F atoms 'j' = skip first square
399 for(dir=0, bit=1; dir<8; dir++, bit += bit) { // loop over directions
400 int i = expo, j = skip, hop = mode, vx, vy, loop = 0;
401 if(!(bit & dirSet)) continue; // does not move in this direction
402 if(dy != 1 || mode & 1024) j = 0; //
403 vx = dx*rot[dir][0] + dy*rot[dir][1]; // rotate step vector
404 vy = dx*rot[dir][2] + dy*rot[dir][3];
405 if(tx < 0) x = f, y = r; // start square
406 else x = tx, y = ty; // from previous to-square if continuation
408 x += vx; y += vy; // step to next square
409 if(y < 0 || y >= BOARD_HEIGHT) break; // vertically off-board: always done
410 if(x < BOARD_LEFT) { if(mode & 128) x += BOARD_RGHT - BOARD_LEFT, loop++; else break; }
411 if(x >= BOARD_RGHT) { if(mode & 128) x -= BOARD_RGHT - BOARD_LEFT, loop++; else break; }
412 if(board[y][x] == DarkSquare) break; // black squares are supposed to be off board
413 if(j) { j--; continue; } // skip irrespective of occupation
414 if(!jump && board[y - vy + vy/2][x - vx + vx/2] != EmptySquare) break; // blocked
415 if(jump > 1 && board[y - vy + vy/2][x - vx + vx/2] == EmptySquare) break; // no hop
416 if(x == f && y == r && !loop) occup = 4; else // start square counts as empty (if not around cylinder!)
417 if(board[y][x] < BlackPawn) occup = 0x101; else
418 if(board[y][x] < EmptySquare) occup = 0x102; else
420 if(cont) { // non-final leg
421 if(mode&16 && his&occup) occup &= 3;// suppress hopping foe in t-mode
422 if(occup & mode) { // valid intermediate square, do continuation
423 char origAtom = *atom;
424 if(!(bit & all)) *atom = rotate[*atom - 'A']; // orth-diag interconversion to make direction valid
425 if(occup & mode & 0x104) // no side effects, merge legs to one move
426 MovesFromString(board, flags, f, r, x, y, dir, cont, cb, cl);
427 if(occup & mode & 3 && (killX < 0 || killX == x && killY == y)) { // destructive first leg
429 MovesFromString(board, flags, f, r, x, y, dir, cont, &OK, &cnt); // count possible continuations
430 if(cnt) { // and if there are
431 if(killX < 0) cb(board, flags, FirstLeg, r, f, y, x, cl); // then generate their first leg
433 MovesFromString(board, flags, f, r, x, y, dir, cont, cb, cl);
437 *atom = origAtom; // undo any interconversion
439 if(occup != 4) break; // occupied squares always terminate the leg
442 if(hop & 32+64) { if(occup != 4) { if(hop & 64 && i != 1) i = 2; hop &= 31; } continue; } // hopper
444 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)
445 cb(board, flags, mine == 1 ? WhiteCapturesEnPassant : BlackCapturesEnPassant, r, f, y, x, cl);
447 if(mode & 1024) { // castling
448 i = 2; // kludge to elongate move indefinitely
449 if(occup == 4) continue; // skip empty squares
450 if((x == BOARD_LEFT + skip || x > BOARD_LEFT + skip && vx < 0 && board[y][x-1-skip] == DarkSquare)
451 && board[y][x] == initialPosition[y][x]) { // reached initial corner piece
452 if(pc != WhiteKing && pc != BlackKing) { // non-royal castling (to be entered as two-leg move via 'Rook')
453 if(killX < 0) cb(board, flags, FirstLeg, r, f, y, x, cl); if(killX < f)
454 legNr <<= 1, cb(board, flags, NormalMove, r, f, y, f - expo, cl), legNr >>= 1;
456 cb(board, flags, mine == 1 ? WhiteQueenSideCastle : BlackQueenSideCastle, r, f, y, f - expo, cl);
458 if((x == BOARD_RGHT-1-skip || x < BOARD_RGHT-1-skip && vx > 0 && board[y][x+1+skip] == DarkSquare)
459 && board[y][x] == initialPosition[y][x]) {
460 if(pc != WhiteKing && pc != BlackKing) {
461 if(killX < 0) cb(board, flags, FirstLeg, r, f, y, x, cl); if(killX > f)
462 legNr <<= 1, cb(board, flags, NormalMove, r, f, y, f + expo, cl), legNr >>= 1;
464 cb(board, flags, mine == 1 ? WhiteKingSideCastle : BlackKingSideCastle, r, f, y, f + expo, cl);
468 if(mode & 16 && (board[y][x] == WhiteKing || board[y][x] == BlackKing)) break; // tame piece, cannot capture royal
469 if(occup & mode) cb(board, flags, y == promoRank ? promo : NormalMove, r, f, y, x, cl); // allowed, generate
470 if(occup != 4) break; // not valid transit square
473 dx = dy; dirSet = ds2; // prepare for diagonal moves of K,Q
474 } while(retry-- && ds2); // and start doing them
475 if(tx >= 0) break; // don't do other atoms in continuation legs
479 // [HGM] move generation now based on hierarchy of subroutines for rays and combinations of rays
482 SlideForward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
487 if (rt >= BOARD_HEIGHT) break;
488 if (SameColor(board[rf][ff], board[rt][ft])) break;
489 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
490 if (board[rt][ft] != EmptySquare) break;
495 SlideBackward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
501 if (SameColor(board[rf][ff], board[rt][ft])) break;
502 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
503 if (board[rt][ft] != EmptySquare) break;
508 SlideVertical (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
510 SlideForward(board, flags, rf, ff, callback, closure);
511 SlideBackward(board, flags, rf, ff, callback, closure);
515 SlideSideways (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
517 int i, s, rt = rf, ft;
518 for(s = -1; s <= 1; s+= 2) {
521 if (ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
522 if (SameColor(board[rf][ff], board[rt][ft])) break;
523 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
524 if (board[rt][ft] != EmptySquare) break;
530 SlideDiagForward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
533 for(s = -1; s <= 1; s+= 2) {
537 if (rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
538 if (SameColor(board[rf][ff], board[rt][ft])) break;
539 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
540 if (board[rt][ft] != EmptySquare) break;
546 SlideDiagBackward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
549 for(s = -1; s <= 1; s+= 2) {
553 if (rt < 0 || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
554 if (SameColor(board[rf][ff], board[rt][ft])) break;
555 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
556 if (board[rt][ft] != EmptySquare) break;
562 Rook (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
564 SlideVertical(board, flags, rf, ff, callback, closure);
565 SlideSideways(board, flags, rf, ff, callback, closure);
569 Bishop (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
571 SlideDiagForward(board, flags, rf, ff, callback, closure);
572 SlideDiagBackward(board, flags, rf, ff, callback, closure);
576 Sting (Board board, int flags, int rf, int ff, int dy, int dx, MoveCallback callback, VOIDSTAR closure)
577 { // Lion-like move of Horned Falcon and Souring Eagle
578 int ft = ff + dx, rt = rf + dy;
579 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) return;
581 if (!SameColor(board[rf][ff], board[rt][ft]))
582 callback(board, flags, board[rt][ft] != EmptySquare ? FirstLeg : NormalMove, rf, ff, rt, ft, closure);
585 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) return;
587 if (!SameColor(board[rf][ff], board[rt][ft]))
588 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
589 if (!SameColor(board[rf][ff], board[rf+dy][ff+dx]))
590 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
595 StepForward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
597 int ft = ff, rt = rf + 1;
598 if (rt >= BOARD_HEIGHT) return;
599 if (SameColor(board[rf][ff], board[rt][ft])) return;
600 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
604 StepBackward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
606 int ft = ff, rt = rf - 1;
608 if (SameColor(board[rf][ff], board[rt][ft])) return;
609 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
613 StepSideways (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
617 if (!(rt >= BOARD_HEIGHT || ft >= BOARD_RGHT) && !SameColor(board[rf][ff], board[rt][ft]))
618 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
620 if (!(rt >= BOARD_HEIGHT || ft < BOARD_LEFT) && !SameColor(board[rf][ff], board[rt][ft]))
621 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
625 StepDiagForward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
628 if (rt >= BOARD_HEIGHT) return;
630 if (!(rt >= BOARD_HEIGHT || ft >= BOARD_RGHT) && !SameColor(board[rf][ff], board[rt][ft]))
631 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
633 if (!(rt >= BOARD_HEIGHT || ft < BOARD_LEFT) && !SameColor(board[rf][ff], board[rt][ft]))
634 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
638 StepDiagBackward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
643 if (!(rt < 0 || ft >= BOARD_RGHT) && !SameColor(board[rf][ff], board[rt][ft]))
644 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
646 if (!(rt < 0 || ft < BOARD_LEFT) && !SameColor(board[rf][ff], board[rt][ft]))
647 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
651 StepVertical (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
653 StepForward(board, flags, rf, ff, callback, closure);
654 StepBackward(board, flags, rf, ff, callback, closure);
658 Ferz (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
660 StepDiagForward(board, flags, rf, ff, callback, closure);
661 StepDiagBackward(board, flags, rf, ff, callback, closure);
665 Wazir (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
667 StepVertical(board, flags, rf, ff, callback, closure);
668 StepSideways(board, flags, rf, ff, callback, closure);
672 Knight (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
675 for (i = -1; i <= 1; i += 2)
676 for (j = -1; j <= 1; j += 2)
677 for (s = 1; s <= 2; s++) {
680 if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
681 && ( gameInfo.variant != VariantXiangqi || board[rf+i*(s-1)][ff+j*(2-s)] == EmptySquare)
682 && !SameColor(board[rf][ff], board[rt][ft]))
683 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
687 /* Call callback once for each pseudo-legal move in the given
688 position, except castling moves. A move is pseudo-legal if it is
689 legal, or if it would be legal except that it leaves the king in
690 check. In the arguments, epfile is EP_NONE if the previous move
691 was not a double pawn push, or the file 0..7 if it was, or
692 EP_UNKNOWN if we don't know and want to allow all e.p. captures.
693 Promotion moves generated are to Queen only.
696 GenPseudoLegal (Board board, int flags, MoveCallback callback, VOIDSTAR closure, ChessSquare filter)
697 // speed: only do moves with this piece type
700 int i, j, d, s, fs, rs, rt, ft, m;
701 int epfile = (signed char)board[EP_STATUS]; // [HGM] gamestate: extract ep status from board
702 int promoRank = gameInfo.variant == VariantMakruk || gameInfo.variant == VariantGrand || gameInfo.variant == VariantChuChess ? 3 : 1;
704 for (rf = 0; rf < BOARD_HEIGHT; rf++)
705 for (ff = BOARD_LEFT; ff < BOARD_RGHT; ff++) {
708 if(board[rf][ff] == EmptySquare) continue;
709 if ((flags & F_WHITE_ON_MOVE) != (board[rf][ff] < BlackPawn)) continue; // [HGM] speed: wrong color
710 m = 0; piece = board[rf][ff];
711 if(PieceToChar(piece) == '~')
712 piece = (ChessSquare) ( DEMOTED piece );
713 if(filter != EmptySquare && piece != filter) continue;
714 if(pieceDefs && pieceDesc[piece]) { // [HGM] gen: use engine-defined moves
715 MovesFromString(board, flags, ff, rf, -1, -1, 0, pieceDesc[piece], callback, closure);
718 if(IS_SHOGI(gameInfo.variant))
719 piece = (ChessSquare) ( SHOGI piece );
721 switch ((int)piece) {
722 /* case EmptySquare: [HGM] this is nonsense, and conflicts with Shogi cases */
724 /* can't happen ([HGM] except for faries...) */
728 if(gameInfo.variant == VariantXiangqi) {
729 /* [HGM] capture and move straight ahead in Xiangqi */
730 if (rf < BOARD_HEIGHT-1 &&
731 !SameColor(board[rf][ff], board[rf + 1][ff]) ) {
732 callback(board, flags, NormalMove,
733 rf, ff, rf + 1, ff, closure);
735 /* and move sideways when across the river */
736 for (s = -1; s <= 1; s += 2) {
737 if (rf >= BOARD_HEIGHT>>1 &&
738 ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
739 !WhitePiece(board[rf][ff+s]) ) {
740 callback(board, flags, NormalMove,
741 rf, ff, rf, ff+s, closure);
746 if (rf < BOARD_HEIGHT-1 && board[rf + 1][ff] == EmptySquare) {
747 callback(board, flags,
748 rf >= BOARD_HEIGHT-1-promoRank ? WhitePromotion : NormalMove,
749 rf, ff, rf + 1, ff, closure);
751 if (rf <= (BOARD_HEIGHT>>1)-3 && board[rf+1][ff] == EmptySquare && // [HGM] grand: also on 3rd rank on 10-board
752 gameInfo.variant != VariantShatranj && /* [HGM] */
753 gameInfo.variant != VariantCourier && /* [HGM] */
754 board[rf+2][ff] == EmptySquare ) {
755 callback(board, flags, NormalMove,
756 rf, ff, rf+2, ff, closure);
758 for (s = -1; s <= 1; s += 2) {
759 if (rf < BOARD_HEIGHT-1 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
760 ((flags & F_KRIEGSPIEL_CAPTURE) ||
761 BlackPiece(board[rf + 1][ff + s]))) {
762 callback(board, flags,
763 rf >= BOARD_HEIGHT-1-promoRank ? WhitePromotion : NormalMove,
764 rf, ff, rf + 1, ff + s, closure);
766 if (rf >= BOARD_HEIGHT+1>>1) {// [HGM] grand: 4th & 5th rank on 10-board
767 if (ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
768 (epfile == ff + s || epfile == EP_UNKNOWN) && rf < BOARD_HEIGHT-3 &&
769 board[rf][ff + s] == BlackPawn &&
770 board[rf+1][ff + s] == EmptySquare) {
771 callback(board, flags, WhiteCapturesEnPassant,
772 rf, ff, rf+1, ff + s, closure);
779 if(gameInfo.variant == VariantXiangqi) {
780 /* [HGM] capture straight ahead in Xiangqi */
781 if (rf > 0 && !SameColor(board[rf][ff], board[rf - 1][ff]) ) {
782 callback(board, flags, NormalMove,
783 rf, ff, rf - 1, ff, closure);
785 /* and move sideways when across the river */
786 for (s = -1; s <= 1; s += 2) {
787 if (rf < BOARD_HEIGHT>>1 &&
788 ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
789 !BlackPiece(board[rf][ff+s]) ) {
790 callback(board, flags, NormalMove,
791 rf, ff, rf, ff+s, closure);
796 if (rf > 0 && board[rf - 1][ff] == EmptySquare) {
797 callback(board, flags,
798 rf <= promoRank ? BlackPromotion : NormalMove,
799 rf, ff, rf - 1, ff, closure);
801 if (rf >= (BOARD_HEIGHT+1>>1)+2 && board[rf-1][ff] == EmptySquare && // [HGM] grand
802 gameInfo.variant != VariantShatranj && /* [HGM] */
803 gameInfo.variant != VariantCourier && /* [HGM] */
804 board[rf-2][ff] == EmptySquare) {
805 callback(board, flags, NormalMove,
806 rf, ff, rf-2, ff, closure);
808 for (s = -1; s <= 1; s += 2) {
809 if (rf > 0 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
810 ((flags & F_KRIEGSPIEL_CAPTURE) ||
811 WhitePiece(board[rf - 1][ff + s]))) {
812 callback(board, flags,
813 rf <= promoRank ? BlackPromotion : NormalMove,
814 rf, ff, rf - 1, ff + s, closure);
816 if (rf < BOARD_HEIGHT>>1) {
817 if (ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
818 (epfile == ff + s || epfile == EP_UNKNOWN) && rf > 2 &&
819 board[rf][ff + s] == WhitePawn &&
820 board[rf-1][ff + s] == EmptySquare) {
821 callback(board, flags, BlackCapturesEnPassant,
822 rf, ff, rf-1, ff + s, closure);
832 for (i = -1; i <= 1; i += 2)
833 for (j = -1; j <= 1; j += 2)
834 for (s = 1; s <= 2; s++) {
837 if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
838 && ( gameInfo.variant != VariantXiangqi || board[rf+i*(s-1)][ff+j*(2-s)] == EmptySquare)
839 && !SameColor(board[rf][ff], board[rt][ft]))
840 callback(board, flags, NormalMove,
841 rf, ff, rt, ft, closure);
845 case SHOGI WhiteKnight:
846 for (s = -1; s <= 1; s += 2) {
847 if (rf < BOARD_HEIGHT-2 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
848 !SameColor(board[rf][ff], board[rf + 2][ff + s])) {
849 callback(board, flags, NormalMove,
850 rf, ff, rf + 2, ff + s, closure);
855 case SHOGI BlackKnight:
856 for (s = -1; s <= 1; s += 2) {
857 if (rf > 1 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
858 !SameColor(board[rf][ff], board[rf - 2][ff + s])) {
859 callback(board, flags, NormalMove,
860 rf, ff, rf - 2, ff + s, closure);
867 for (d = 0; d <= 1; d++)
868 for (s = -1; s <= 1; s += 2) {
871 rt = rf + (i * s) * d;
872 ft = ff + (i * s) * (1 - d);
873 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
874 if (m == 0 && board[rt][ft] == EmptySquare)
875 callback(board, flags, NormalMove,
876 rf, ff, rt, ft, closure);
877 if (m == 1 && board[rt][ft] != EmptySquare &&
878 !SameColor(board[rf][ff], board[rt][ft]) )
879 callback(board, flags, NormalMove,
880 rf, ff, rt, ft, closure);
881 if (board[rt][ft] != EmptySquare && m++) break;
886 /* Gold General (and all its promoted versions) . First do the */
887 /* diagonal forward steps, then proceed as normal Wazir */
888 case SHOGI (PROMOTED WhitePawn):
889 if(gameInfo.variant == VariantShogi) goto WhiteGold;
890 case SHOGI (PROMOTED BlackPawn):
891 if(gameInfo.variant == VariantShogi) goto BlackGold;
892 SlideVertical(board, flags, rf, ff, callback, closure);
895 case SHOGI (PROMOTED WhiteKnight):
896 if(gameInfo.variant == VariantShogi) goto WhiteGold;
897 case SHOGI BlackDrunk:
898 case SHOGI BlackAlfil:
899 Ferz(board, flags, rf, ff, callback, closure);
900 StepSideways(board, flags, rf, ff, callback, closure);
901 StepBackward(board, flags, rf, ff, callback, closure);
904 case SHOGI (PROMOTED BlackKnight):
905 if(gameInfo.variant == VariantShogi) goto BlackGold;
906 case SHOGI WhiteDrunk:
907 case SHOGI WhiteAlfil:
908 Ferz(board, flags, rf, ff, callback, closure);
909 StepSideways(board, flags, rf, ff, callback, closure);
910 StepForward(board, flags, rf, ff, callback, closure);
914 case SHOGI WhiteStag:
915 case SHOGI BlackStag:
916 if(gameInfo.variant == VariantShogi) goto BlackGold;
917 SlideVertical(board, flags, rf, ff, callback, closure);
918 Ferz(board, flags, rf, ff, callback, closure);
919 StepSideways(board, flags, rf, ff, callback, closure);
922 case SHOGI (PROMOTED WhiteQueen):
923 case SHOGI WhiteTokin:
924 case SHOGI WhiteWazir:
926 StepDiagForward(board, flags, rf, ff, callback, closure);
927 Wazir(board, flags, rf, ff, callback, closure);
930 case SHOGI (PROMOTED BlackQueen):
931 case SHOGI BlackTokin:
932 case SHOGI BlackWazir:
934 StepDiagBackward(board, flags, rf, ff, callback, closure);
935 Wazir(board, flags, rf, ff, callback, closure);
940 Wazir(board, flags, rf, ff, callback, closure);
943 case SHOGI WhiteMarshall:
944 case SHOGI BlackMarshall:
945 Ferz(board, flags, rf, ff, callback, closure);
946 for (d = 0; d <= 1; d++)
947 for (s = -2; s <= 2; s += 4) {
949 ft = ff + s * (1 - d);
950 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) continue;
951 if (!SameColor(board[rf][ff], board[rt][ft]) )
952 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
956 case SHOGI WhiteAngel:
957 case SHOGI BlackAngel:
958 Wazir(board, flags, rf, ff, callback, closure);
962 /* [HGM] support Shatranj pieces */
963 for (rs = -1; rs <= 1; rs += 2)
964 for (fs = -1; fs <= 1; fs += 2) {
967 if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
968 && ( gameInfo.variant != VariantXiangqi ||
969 board[rf+rs][ff+fs] == EmptySquare && (2*rf < BOARD_HEIGHT) == (2*rt < BOARD_HEIGHT) )
971 && !SameColor(board[rf][ff], board[rt][ft]))
972 callback(board, flags, NormalMove,
973 rf, ff, rt, ft, closure);
974 if(gameInfo.variant == VariantShatranj || gameInfo.variant == VariantCourier ||
975 gameInfo.variant == VariantChu || gameInfo.variant == VariantXiangqi) continue; // classical Alfil
976 rt = rf + rs; // in unknown variant we assume Modern Elephant, which can also do one step
978 if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
979 && !SameColor(board[rf][ff], board[rt][ft]))
980 callback(board, flags, NormalMove,
981 rf, ff, rt, ft, closure);
983 if(gameInfo.variant == VariantSpartan)
984 for(fs = -1; fs <= 1; fs += 2) {
986 if (!(ft < BOARD_LEFT || ft >= BOARD_RGHT) && board[rf][ft] == EmptySquare)
987 callback(board, flags, NormalMove, rf, ff, rf, ft, closure);
991 /* Make Dragon-Horse also do Dababba moves outside Shogi, for better disambiguation in variant Fairy */
994 if(gameInfo.variant == VariantChuChess) goto DragonHorse;
995 for (d = 0; d <= 1; d++) // Dababba moves that Rook cannot do
996 for (s = -2; s <= 2; s += 4) {
998 ft = ff + s * (1 - d);
999 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) continue;
1000 if (SameColor(board[rf][ff], board[rt][ft])) continue;
1001 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
1004 /* Shogi Dragon Horse has to continue with Wazir after Bishop */
1005 case SHOGI WhiteCardinal:
1006 case SHOGI BlackCardinal:
1007 case SHOGI WhitePCardinal:
1008 case SHOGI BlackPCardinal:
1010 Bishop(board, flags, rf, ff, callback, closure);
1011 Wazir(board, flags, rf, ff, callback, closure);
1014 /* Capablanca Archbishop continues as Knight */
1017 Knight(board, flags, rf, ff, callback, closure);
1019 /* Shogi Bishops are ordinary Bishops */
1020 case SHOGI WhiteBishop:
1021 case SHOGI BlackBishop:
1022 case SHOGI WhitePBishop:
1023 case SHOGI BlackPBishop:
1026 Bishop(board, flags, rf, ff, callback, closure);
1029 /* Shogi Lance is unlike anything, and asymmetric at that */
1030 case SHOGI WhiteQueen:
1031 if(gameInfo.variant == VariantChu) goto doQueen;
1035 if (rt >= BOARD_HEIGHT) break;
1036 if (SameColor(board[rf][ff], board[rt][ft])) break;
1037 callback(board, flags, NormalMove,
1038 rf, ff, rt, ft, closure);
1039 if (board[rt][ft] != EmptySquare) break;
1043 case SHOGI BlackQueen:
1044 if(gameInfo.variant == VariantChu) goto doQueen;
1049 if (SameColor(board[rf][ff], board[rt][ft])) break;
1050 callback(board, flags, NormalMove,
1051 rf, ff, rt, ft, closure);
1052 if (board[rt][ft] != EmptySquare) break;
1056 /* Make Dragon-King Dababba & Rook-like outside Shogi, for better disambiguation in variant Fairy */
1059 if(gameInfo.variant == VariantChuChess) goto DragonKing;
1060 for (d = 0; d <= 1; d++) // Dababba moves that Rook cannot do
1061 for (s = -2; s <= 2; s += 4) {
1063 ft = ff + s * (1 - d);
1064 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) continue;
1065 if (board[rf+rt>>1][ff+ft>>1] == EmptySquare && gameInfo.variant != VariantSpartan) continue;
1066 if (SameColor(board[rf][ff], board[rt][ft])) continue;
1067 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
1069 if(gameInfo.variant == VariantSpartan) // in Spartan Chess restrict range to modern Dababba
1070 Wazir(board, flags, rf, ff, callback, closure);
1072 Rook(board, flags, rf, ff, callback, closure);
1075 /* Shogi Dragon King has to continue as Ferz after Rook moves */
1076 case SHOGI WhiteDragon:
1077 case SHOGI BlackDragon:
1078 case SHOGI WhitePDragon:
1079 case SHOGI BlackPDragon:
1081 Rook(board, flags, rf, ff, callback, closure);
1082 Ferz(board, flags, rf, ff, callback, closure);
1086 /* Capablanca Chancellor sets flag to continue as Knight */
1089 Rook(board, flags, rf, ff, callback, closure);
1090 if(gameInfo.variant == VariantSpartan) // in Spartan Chess Chancellor is used for Dragon King.
1091 Ferz(board, flags, rf, ff, callback, closure);
1093 Knight(board, flags, rf, ff, callback, closure);
1096 /* Shogi Rooks are ordinary Rooks */
1097 case SHOGI WhiteRook:
1098 case SHOGI BlackRook:
1099 case SHOGI WhitePRook:
1100 case SHOGI BlackPRook:
1103 Rook(board, flags, rf, ff, callback, closure);
1108 case SHOGI WhiteMother:
1109 case SHOGI BlackMother:
1111 Rook(board, flags, rf, ff, callback, closure);
1112 Bishop(board, flags, rf, ff, callback, closure);
1115 case SHOGI WhitePawn:
1116 StepForward(board, flags, rf, ff, callback, closure);
1119 case SHOGI BlackPawn:
1120 StepBackward(board, flags, rf, ff, callback, closure);
1124 if(gameInfo.variant != VariantMakruk && gameInfo.variant != VariantASEAN) goto commoner;
1125 case SHOGI WhiteFerz:
1126 Ferz(board, flags, rf, ff, callback, closure);
1127 StepForward(board, flags, rf, ff, callback, closure);
1131 if(gameInfo.variant != VariantMakruk && gameInfo.variant != VariantASEAN) goto commoner;
1132 case SHOGI BlackFerz:
1133 StepBackward(board, flags, rf, ff, callback, closure);
1137 /* [HGM] support Shatranj pieces */
1138 Ferz(board, flags, rf, ff, callback, closure);
1143 Knight(board, flags, rf, ff, callback, closure); // [HGM] superchess: use for Centaur
1146 case SHOGI WhiteMonarch:
1147 case SHOGI BlackMonarch:
1148 case SHOGI WhiteKing:
1149 case SHOGI BlackKing:
1152 Ferz(board, flags, rf, ff, callback, closure);
1153 Wazir(board, flags, rf, ff, callback, closure);
1156 case WhiteNightrider:
1157 case BlackNightrider:
1158 for (i = -1; i <= 1; i += 2)
1159 for (j = -1; j <= 1; j += 2)
1160 for (s = 1; s <= 2; s++) { int k;
1163 ft = ff + k*j*(3-s);
1164 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
1165 if (SameColor(board[rf][ff], board[rt][ft])) break;
1166 callback(board, flags, NormalMove,
1167 rf, ff, rt, ft, closure);
1168 if (board[rt][ft] != EmptySquare) break;
1174 Bishop(board, flags, rf, ff, callback, closure);
1175 Rook(board, flags, rf, ff, callback, closure);
1176 Knight(board, flags, rf, ff, callback, closure);
1179 // Use Lance as Berolina / Spartan Pawn.
1181 if(gameInfo.variant == VariantSuper) goto Amazon;
1182 if (rf < BOARD_HEIGHT-1 && BlackPiece(board[rf + 1][ff]))
1183 callback(board, flags,
1184 rf >= BOARD_HEIGHT-1-promoRank ? WhitePromotion : NormalMove,
1185 rf, ff, rf + 1, ff, closure);
1186 for (s = -1; s <= 1; s += 2) {
1187 if (rf < BOARD_HEIGHT-1 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT && board[rf + 1][ff + s] == EmptySquare)
1188 callback(board, flags,
1189 rf >= BOARD_HEIGHT-1-promoRank ? WhitePromotion : NormalMove,
1190 rf, ff, rf + 1, ff + s, closure);
1191 if (rf == 1 && ff + 2*s >= BOARD_LEFT && ff + 2*s < BOARD_RGHT && board[3][ff + 2*s] == EmptySquare )
1192 callback(board, flags, NormalMove, rf, ff, 3, ff + 2*s, closure);
1197 if(gameInfo.variant == VariantSuper) goto Amazon;
1198 if (rf > 0 && WhitePiece(board[rf - 1][ff]))
1199 callback(board, flags,
1200 rf <= promoRank ? BlackPromotion : NormalMove,
1201 rf, ff, rf - 1, ff, closure);
1202 for (s = -1; s <= 1; s += 2) {
1203 if (rf > 0 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT && board[rf - 1][ff + s] == EmptySquare)
1204 callback(board, flags,
1205 rf <= promoRank ? BlackPromotion : NormalMove,
1206 rf, ff, rf - 1, ff + s, closure);
1207 if (rf == BOARD_HEIGHT-2 && ff + 2*s >= BOARD_LEFT && ff + 2*s < BOARD_RGHT && board[rf-2][ff + 2*s] == EmptySquare )
1208 callback(board, flags, NormalMove, rf, ff, rf-2, ff + 2*s, closure);
1212 case SHOGI WhiteNothing:
1213 case SHOGI BlackNothing:
1214 case SHOGI WhiteLion:
1215 case SHOGI BlackLion:
1218 for(rt = rf - 2; rt <= rf + 2; rt++) for(ft = ff - 2; ft <= ff + 2; ft++) {
1219 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) continue;
1220 if (!(ff == ft && rf == rt) && SameColor(board[rf][ff], board[rt][ft])) continue;
1221 i = (killX >= 0 && (rt-killY)*(rt-killY) + (killX-ft)*(killX-ft) < 3); legNr += 2*i;
1222 callback(board, flags, (rt-rf)*(rt-rf) + (ff-ft)*(ff-ft) < 3 && board[rt][ft] != EmptySquare ? FirstLeg : NormalMove,
1223 rf, ff, rt, ft, closure);
1228 case SHOGI WhiteFalcon:
1229 case SHOGI BlackFalcon:
1230 case SHOGI WhitePDagger:
1231 case SHOGI BlackPDagger:
1232 SlideSideways(board, flags, rf, ff, callback, closure);
1233 StepVertical(board, flags, rf, ff, callback, closure);
1236 case SHOGI WhiteCobra:
1237 case SHOGI BlackCobra:
1238 StepVertical(board, flags, rf, ff, callback, closure);
1241 case SHOGI (PROMOTED WhiteFerz):
1242 if(gameInfo.variant == VariantShogi) goto WhiteGold;
1243 case SHOGI (PROMOTED BlackFerz):
1244 if(gameInfo.variant == VariantShogi) goto BlackGold;
1245 case SHOGI WhitePSword:
1246 case SHOGI BlackPSword:
1247 SlideVertical(board, flags, rf, ff, callback, closure);
1248 StepSideways(board, flags, rf, ff, callback, closure);
1251 case SHOGI WhiteUnicorn:
1252 case SHOGI BlackUnicorn:
1253 Ferz(board, flags, rf, ff, callback, closure);
1254 StepVertical(board, flags, rf, ff, callback, closure);
1257 case SHOGI WhiteMan:
1258 StepDiagForward(board, flags, rf, ff, callback, closure);
1259 StepVertical(board, flags, rf, ff, callback, closure);
1262 case SHOGI BlackMan:
1263 StepDiagBackward(board, flags, rf, ff, callback, closure);
1264 StepVertical(board, flags, rf, ff, callback, closure);
1267 case SHOGI WhiteHCrown:
1268 case SHOGI BlackHCrown:
1269 Bishop(board, flags, rf, ff, callback, closure);
1270 SlideSideways(board, flags, rf, ff, callback, closure);
1273 case SHOGI WhiteCrown:
1274 case SHOGI BlackCrown:
1275 Bishop(board, flags, rf, ff, callback, closure);
1276 SlideVertical(board, flags, rf, ff, callback, closure);
1279 case SHOGI WhiteHorned:
1280 Sting(board, flags, rf, ff, 1, 0, callback, closure);
1281 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1282 if(killX >= 0) break;
1283 Bishop(board, flags, rf, ff, callback, closure);
1284 SlideSideways(board, flags, rf, ff, callback, closure);
1285 SlideBackward(board, flags, rf, ff, callback, closure);
1288 case SHOGI BlackHorned:
1289 Sting(board, flags, rf, ff, -1, 0, callback, closure);
1290 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1291 if(killX >= 0) break;
1292 Bishop(board, flags, rf, ff, callback, closure);
1293 SlideSideways(board, flags, rf, ff, callback, closure);
1294 SlideForward(board, flags, rf, ff, callback, closure);
1297 case SHOGI WhiteEagle:
1298 Sting(board, flags, rf, ff, 1, 1, callback, closure);
1299 Sting(board, flags, rf, ff, 1, -1, callback, closure);
1300 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1301 if(killX >= 0) break;
1302 Rook(board, flags, rf, ff, callback, closure);
1303 SlideDiagBackward(board, flags, rf, ff, callback, closure);
1306 case SHOGI BlackEagle:
1307 Sting(board, flags, rf, ff, -1, 1, callback, closure);
1308 Sting(board, flags, rf, ff, -1, -1, callback, closure);
1309 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1310 if(killX >= 0) break;
1311 Rook(board, flags, rf, ff, callback, closure);
1312 SlideDiagForward(board, flags, rf, ff, callback, closure);
1315 case SHOGI WhiteDolphin:
1316 case SHOGI BlackHorse:
1317 SlideDiagBackward(board, flags, rf, ff, callback, closure);
1318 SlideVertical(board, flags, rf, ff, callback, closure);
1321 case SHOGI BlackDolphin:
1322 case SHOGI WhiteHorse:
1323 SlideDiagForward(board, flags, rf, ff, callback, closure);
1324 SlideVertical(board, flags, rf, ff, callback, closure);
1327 case SHOGI WhiteLance:
1328 SlideForward(board, flags, rf, ff, callback, closure);
1331 case SHOGI BlackLance:
1332 SlideBackward(board, flags, rf, ff, callback, closure);
1335 case WhiteFalcon: // [HGM] wild: for wildcards, self-capture symbolizes move to anywhere
1339 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1352 int rFilter, fFilter; // [HGM] speed: sorry, but I get a bit tired of this closure madness
1353 Board xqCheckers, nullBoard;
1355 extern void GenLegalCallback P((Board board, int flags, ChessMove kind,
1356 int rf, int ff, int rt, int ft,
1360 GenLegalCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1362 register GenLegalClosure *cl = (GenLegalClosure *) closure;
1364 if(rFilter >= 0 && rFilter != rt || fFilter >= 0 && fFilter != ft) return; // [HGM] speed: ignore moves with wrong to-square
1366 if (board[EP_STATUS] == EP_IRON_LION && (board[rt][ft] == WhiteLion || board[rt][ft] == BlackLion)) return; //[HGM] lion
1368 if (!(flags & F_IGNORE_CHECK) ) {
1369 int check, promo = (gameInfo.variant == VariantSpartan && kind == BlackPromotion);
1372 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++)
1373 kings += (board[r][f] == BlackKing);
1377 board[rf][ff] = BlackKing; // [HGM] spartan: promote to King before check-test
1379 check = CheckTest(board, flags, rf, ff, rt, ft,
1380 kind == WhiteCapturesEnPassant ||
1381 kind == BlackCapturesEnPassant);
1382 if(promo) board[rf][ff] = BlackLance;
1385 if (flags & F_ATOMIC_CAPTURE) {
1386 if (board[rt][ft] != EmptySquare ||
1387 kind == WhiteCapturesEnPassant || kind == BlackCapturesEnPassant) {
1389 ChessSquare king = (flags & F_WHITE_ON_MOVE) ? WhiteKing : BlackKing;
1390 if (board[rf][ff] == king) return;
1391 for (r = rt-1; r <= rt+1; r++) {
1392 for (f = ft-1; f <= ft+1; f++) {
1393 if (r >= 0 && r < BOARD_HEIGHT && f >= BOARD_LEFT && f < BOARD_RGHT &&
1394 board[r][f] == king) return;
1399 cl->cb(board, flags, kind, rf, ff, rt, ft, cl->cl);
1406 int captures; // [HGM] losers
1407 } LegalityTestClosure;
1410 /* Like GenPseudoLegal, but (1) include castling moves, (2) unless
1411 F_IGNORE_CHECK is set in the flags, omit moves that would leave the
1412 king in check, and (3) if F_ATOMIC_CAPTURE is set in the flags, omit
1413 moves that would destroy your own king. The CASTLE_OK flags are
1414 true if castling is not yet ruled out by a move of the king or
1415 rook. Return TRUE if the player on move is currently in check and
1416 F_IGNORE_CHECK is not set. [HGM] add castlingRights parameter */
1418 GenLegal (Board board, int flags, MoveCallback callback, VOIDSTAR closure, ChessSquare filter)
1421 int ff, ft, k, left, right, swap;
1422 int ignoreCheck = (flags & F_IGNORE_CHECK) != 0;
1423 ChessSquare wKing = WhiteKing, bKing = BlackKing, *castlingRights = board[CASTLING];
1424 int inCheck = !ignoreCheck && CheckTest(board, flags, -1, -1, -1, -1, FALSE); // kludge alert: this would mark pre-existing checkers if status==1
1429 xqCheckers[EP_STATUS] *= 2; // quasi: if previous CheckTest has been marking, we now set flag for suspending same checkers
1430 if(filter == EmptySquare) rFilter = fFilter = -1; // [HGM] speed: do not filter on square if we do not filter on piece
1431 GenPseudoLegal(board, flags, GenLegalCallback, (VOIDSTAR) &cl, filter);
1433 if (inCheck) return TRUE;
1435 /* Generate castling moves */
1436 if(gameInfo.variant == VariantKnightmate) { /* [HGM] Knightmate */
1437 wKing = WhiteUnicorn; bKing = BlackUnicorn;
1440 p = (flags & F_WHITE_ON_MOVE ? pieceDesc[wKing] : pieceDesc[bKing]);
1441 if(p && strchr(p, 'O')) return FALSE; // [HGM] gen: castlings were already generated from string
1443 for (ff = BOARD_WIDTH>>1; ff >= (BOARD_WIDTH-1)>>1; ff-- /*ics wild 1*/) {
1444 if ((flags & F_WHITE_ON_MOVE) &&
1445 (flags & F_WHITE_KCASTLE_OK) &&
1446 board[0][ff] == wKing &&
1447 board[0][ff + 1] == EmptySquare &&
1448 board[0][ff + 2] == EmptySquare &&
1449 board[0][BOARD_RGHT-3] == EmptySquare &&
1450 board[0][BOARD_RGHT-2] == EmptySquare &&
1451 board[0][BOARD_RGHT-1] == WhiteRook &&
1452 castlingRights[0] != NoRights && /* [HGM] check rights */
1453 ( castlingRights[2] == ff || castlingRights[6] == ff ) &&
1455 (!CheckTest(board, flags, 0, ff, 0, ff + 1, FALSE) &&
1456 !CheckTest(board, flags, 0, ff, 0, BOARD_RGHT-3, FALSE) &&
1457 (gameInfo.variant != VariantJanus || !CheckTest(board, flags, 0, ff, 0, BOARD_RGHT-2, FALSE)) &&
1458 !CheckTest(board, flags, 0, ff, 0, ff + 2, FALSE)))) {
1460 callback(board, flags,
1461 ff==BOARD_WIDTH>>1 ? WhiteKingSideCastle : WhiteKingSideCastleWild,
1462 0, ff, 0, ff + ((gameInfo.boardWidth+2)>>2) + (gameInfo.variant == VariantJanus), closure);
1464 if ((flags & F_WHITE_ON_MOVE) &&
1465 (flags & F_WHITE_QCASTLE_OK) &&
1466 board[0][ff] == wKing &&
1467 board[0][ff - 1] == EmptySquare &&
1468 board[0][ff - 2] == EmptySquare &&
1469 board[0][BOARD_LEFT+2] == EmptySquare &&
1470 board[0][BOARD_LEFT+1] == EmptySquare &&
1471 board[0][BOARD_LEFT+0] == WhiteRook &&
1472 castlingRights[1] != NoRights && /* [HGM] check rights */
1473 ( castlingRights[2] == ff || castlingRights[6] == ff ) &&
1475 (!CheckTest(board, flags, 0, ff, 0, ff - 1, FALSE) &&
1476 !CheckTest(board, flags, 0, ff, 0, BOARD_LEFT+3, FALSE) &&
1477 !CheckTest(board, flags, 0, ff, 0, ff - 2, FALSE)))) {
1479 callback(board, flags,
1480 ff==BOARD_WIDTH>>1 ? WhiteQueenSideCastle : WhiteQueenSideCastleWild,
1481 0, ff, 0, ff - ((gameInfo.boardWidth+2)>>2), closure);
1483 if (!(flags & F_WHITE_ON_MOVE) &&
1484 (flags & F_BLACK_KCASTLE_OK) &&
1485 board[BOARD_HEIGHT-1][ff] == bKing &&
1486 board[BOARD_HEIGHT-1][ff + 1] == EmptySquare &&
1487 board[BOARD_HEIGHT-1][ff + 2] == EmptySquare &&
1488 board[BOARD_HEIGHT-1][BOARD_RGHT-3] == EmptySquare &&
1489 board[BOARD_HEIGHT-1][BOARD_RGHT-2] == EmptySquare &&
1490 board[BOARD_HEIGHT-1][BOARD_RGHT-1] == BlackRook &&
1491 castlingRights[3] != NoRights && /* [HGM] check rights */
1492 ( castlingRights[5] == ff || castlingRights[7] == ff ) &&
1494 (!CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff + 1, FALSE) &&
1495 !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, BOARD_RGHT-3, FALSE) &&
1496 (gameInfo.variant != VariantJanus || !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, BOARD_RGHT-2, FALSE)) &&
1497 !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff + 2, FALSE)))) {
1499 callback(board, flags,
1500 ff==BOARD_WIDTH>>1 ? BlackKingSideCastle : BlackKingSideCastleWild,
1501 BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff + ((gameInfo.boardWidth+2)>>2) + (gameInfo.variant == VariantJanus), closure);
1503 if (!(flags & F_WHITE_ON_MOVE) &&
1504 (flags & F_BLACK_QCASTLE_OK) &&
1505 board[BOARD_HEIGHT-1][ff] == bKing &&
1506 board[BOARD_HEIGHT-1][ff - 1] == EmptySquare &&
1507 board[BOARD_HEIGHT-1][ff - 2] == EmptySquare &&
1508 board[BOARD_HEIGHT-1][BOARD_LEFT+2] == EmptySquare &&
1509 board[BOARD_HEIGHT-1][BOARD_LEFT+1] == EmptySquare &&
1510 board[BOARD_HEIGHT-1][BOARD_LEFT+0] == BlackRook &&
1511 castlingRights[4] != NoRights && /* [HGM] check rights */
1512 ( castlingRights[5] == ff || castlingRights[7] == ff ) &&
1514 (!CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff - 1, FALSE) &&
1515 !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, BOARD_LEFT+3, FALSE) &&
1516 !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff - 2, FALSE)))) {
1518 callback(board, flags,
1519 ff==BOARD_WIDTH>>1 ? BlackQueenSideCastle : BlackQueenSideCastleWild,
1520 BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff - ((gameInfo.boardWidth+2)>>2), closure);
1524 if((swap = gameInfo.variant == VariantSChess) || flags & F_FRC_TYPE_CASTLING) {
1526 /* generate all potential FRC castling moves (KxR), ignoring flags */
1527 /* [HGM] test if the Rooks we find have castling rights */
1528 /* In S-Chess we generate RxK for allowed castlings, for gating at Rook square */
1531 if ((flags & F_WHITE_ON_MOVE) != 0) {
1532 ff = castlingRights[2]; /* King file if we have any rights */
1533 if(ff != NoRights && board[0][ff] == WhiteKing) {
1534 if (appData.debugMode) {
1535 fprintf(debugFP, "FRC castling, %d %d %d %d %d %d\n",
1536 castlingRights[0],castlingRights[1],ff,castlingRights[3],castlingRights[4],castlingRights[5]);
1538 ft = castlingRights[0]; /* Rook file if we have H-side rights */
1540 right = BOARD_RGHT-2;
1541 if(ff == BOARD_RGHT-2) left = right = ff-1; /* special case */
1542 for(k=left; k<=right && ft != NoRights; k++) /* first test if blocked */
1543 if(k != ft && board[0][k] != EmptySquare) ft = NoRights;
1544 for(k=left; k<right && ft != NoRights; k++) /* then if not checked */
1545 if(!ignoreCheck && CheckTest(board, flags, 0, ff, 0, k, FALSE)) ft = NoRights;
1546 if(ft != NoRights && board[0][ft] == WhiteRook) {
1547 if(flags & F_FRC_TYPE_CASTLING) callback(board, flags, WhiteHSideCastleFR, 0, ff, 0, ft, closure);
1548 if(swap) callback(board, flags, WhiteHSideCastleFR, 0, ft, 0, ff, closure);
1551 ft = castlingRights[1]; /* Rook file if we have A-side rights */
1552 left = BOARD_LEFT+2;
1554 if(ff <= BOARD_LEFT+2) { left = ff+1; right = BOARD_LEFT+3; }
1555 for(k=left; k<=right && ft != NoRights; k++) /* first test if blocked */
1556 if(k != ft && board[0][k] != EmptySquare) ft = NoRights;
1557 if(ft == 0 && ff != 1 && board[0][1] != EmptySquare) ft = NoRights; /* Rook can be blocked on b1 */
1558 if(ff > BOARD_LEFT+2)
1559 for(k=left+1; k<=right && ft != NoRights; k++) /* then if not checked */
1560 if(!ignoreCheck && CheckTest(board, flags, 0, ff, 0, k, FALSE)) ft = NoRights;
1561 if(ft != NoRights && board[0][ft] == WhiteRook) {
1562 if(flags & F_FRC_TYPE_CASTLING) callback(board, flags, WhiteASideCastleFR, 0, ff, 0, ft, closure);
1563 if(swap) callback(board, flags, WhiteASideCastleFR, 0, ft, 0, ff, closure);
1567 ff = castlingRights[5]; /* King file if we have any rights */
1568 if(ff != NoRights && board[BOARD_HEIGHT-1][ff] == BlackKing) {
1569 ft = castlingRights[3]; /* Rook file if we have H-side rights */
1571 right = BOARD_RGHT-2;
1572 if(ff == BOARD_RGHT-2) left = right = ff-1; /* special case */
1573 for(k=left; k<=right && ft != NoRights; k++) /* first test if blocked */
1574 if(k != ft && board[BOARD_HEIGHT-1][k] != EmptySquare) ft = NoRights;
1575 for(k=left; k<right && ft != NoRights; k++) /* then if not checked */
1576 if(!ignoreCheck && CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, k, FALSE)) ft = NoRights;
1577 if(ft != NoRights && board[BOARD_HEIGHT-1][ft] == BlackRook) {
1578 if(flags & F_FRC_TYPE_CASTLING) callback(board, flags, BlackHSideCastleFR, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ft, closure);
1579 if(swap) callback(board, flags, BlackHSideCastleFR, BOARD_HEIGHT-1, ft, BOARD_HEIGHT-1, ff, closure);
1582 ft = castlingRights[4]; /* Rook file if we have A-side rights */
1583 left = BOARD_LEFT+2;
1585 if(ff <= BOARD_LEFT+2) { left = ff+1; right = BOARD_LEFT+3; }
1586 for(k=left; k<=right && ft != NoRights; k++) /* first test if blocked */
1587 if(k != ft && board[BOARD_HEIGHT-1][k] != EmptySquare) ft = NoRights;
1588 if(ft == 0 && ff != 1 && board[BOARD_HEIGHT-1][1] != EmptySquare) ft = NoRights; /* Rook can be blocked on b8 */
1589 if(ff > BOARD_LEFT+2)
1590 for(k=left+1; k<=right && ft != NoRights; k++) /* then if not checked */
1591 if(!ignoreCheck && CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, k, FALSE)) ft = NoRights;
1592 if(ft != NoRights && board[BOARD_HEIGHT-1][ft] == BlackRook) {
1593 if(flags & F_FRC_TYPE_CASTLING) callback(board, flags, BlackASideCastleFR, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ft, closure);
1594 if(swap) callback(board, flags, BlackASideCastleFR, BOARD_HEIGHT-1, ft, BOARD_HEIGHT-1, ff, closure);
1611 extern void CheckTestCallback P((Board board, int flags, ChessMove kind,
1612 int rf, int ff, int rt, int ft,
1617 CheckTestCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1619 register CheckTestClosure *cl = (CheckTestClosure *) closure;
1621 if (rt == cl->rking && ft == cl->fking) {
1622 if(xqCheckers[EP_STATUS] >= 2 && xqCheckers[rf][ff]) return; // checker is piece with suspended checking power
1624 xqCheckers[rf][ff] = xqCheckers[EP_STATUS] & 1; // remember who is checking (if status == 1)
1626 if( board[EP_STATUS] == EP_ROYAL_LION && (board[rt][ft] == WhiteLion || board[rt][ft] == BlackLion)
1627 && (gameInfo.variant != VariantLion || board[rf][ff] != WhiteKing && board[rf][ff] != BlackKing) )
1628 cl->check++; // [HGM] lion: forbidden counterstrike against Lion equated to putting yourself in check
1632 /* If the player on move were to move from (rf, ff) to (rt, ft), would
1633 he leave himself in check? Or if rf == -1, is the player on move
1634 in check now? enPassant must be TRUE if the indicated move is an
1635 e.p. capture. The possibility of castling out of a check along the
1636 back rank is not accounted for (i.e., we still return nonzero), as
1637 this is illegal anyway. Return value is the number of times the
1638 king is in check. */
1640 CheckTest (Board board, int flags, int rf, int ff, int rt, int ft, int enPassant)
1642 CheckTestClosure cl;
1643 ChessSquare king = flags & F_WHITE_ON_MOVE ? WhiteKing : BlackKing;
1644 ChessSquare captured = EmptySquare, ep=0, trampled=0;
1645 int saveKill = killX;
1646 /* Suppress warnings on uninitialized variables */
1648 if(gameInfo.variant == VariantXiangqi)
1649 king = flags & F_WHITE_ON_MOVE ? WhiteWazir : BlackWazir;
1650 if(gameInfo.variant == VariantKnightmate)
1651 king = flags & F_WHITE_ON_MOVE ? WhiteUnicorn : BlackUnicorn;
1652 if(gameInfo.variant == VariantChu || gameInfo.variant == VariantShogi) { // strictly speaking this is not needed, as Chu officially has no check
1653 int r, f, k = king, royals=0, prince = flags & F_WHITE_ON_MOVE ? WhiteMonarch : BlackMonarch;
1654 if(gameInfo.variant == VariantShogi) prince -= 11; // White/BlackFalcon
1655 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++) {
1656 if(board[r][f] == k || board[r][f] == prince) {
1657 if(++royals > 1) return FALSE; // no check if we have two royals (ignores double captureby Lion!)
1658 king = board[r][f]; // remember hich one we had
1665 captured = board[rf][ft];
1666 board[rf][ft] = EmptySquare;
1668 captured = board[rt][ft];
1669 if(killX >= 0) { trampled = board[killY][killX]; board[killY][killX] = EmptySquare; killX = -1; }
1671 if(rf == DROP_RANK) board[rt][ft] = ff; else { // [HGM] drop
1672 board[rt][ft] = board[rf][ff];
1673 if(rf != rt || ff != ft) board[rf][ff] = EmptySquare;
1675 ep = board[EP_STATUS];
1676 if( captured == WhiteLion || captured == BlackLion ) { // [HGM] lion: Chu Lion-capture rules
1677 ChessSquare victim = killX < 0 ? EmptySquare : trampled;
1678 if( (board[rt][ft] == WhiteLion || board[rt][ft] == BlackLion) && // capturer is Lion
1679 (ff - ft > 1 || ft - ff > 1 || rf - rt > 1 || rt - rf > 1) && // captures from a distance
1680 (victim == EmptySquare || victim == WhitePawn || victim == BlackPawn) ) // no or worthless 'bridge'
1681 board[EP_STATUS] = EP_ROYAL_LION; // on distant Lion x Lion victim must not be pseudo-legally protected
1685 /* For compatibility with ICS wild 9, we scan the board in the
1686 order a1, a2, a3, ... b1, b2, ..., h8 to find the first king,
1687 and we test only whether that one is in check. */
1688 for (cl.fking = BOARD_LEFT+0; cl.fking < BOARD_RGHT; cl.fking++)
1689 for (cl.rking = 0; cl.rking < BOARD_HEIGHT; cl.rking++) {
1690 if (board[cl.rking][cl.fking] == king) {
1692 if(gameInfo.variant == VariantXiangqi) {
1693 /* [HGM] In Xiangqi opposing Kings means check as well */
1695 dir = (king >= BlackPawn) ? -1 : 1;
1696 for( i=cl.rking+dir; i>=0 && i<BOARD_HEIGHT &&
1697 board[i][cl.fking] == EmptySquare; i+=dir );
1698 if(i>=0 && i<BOARD_HEIGHT &&
1699 board[i][cl.fking] == (dir>0 ? BlackWazir : WhiteWazir) )
1702 GenPseudoLegal(board, flags ^ F_WHITE_ON_MOVE, CheckTestCallback, (VOIDSTAR) &cl, EmptySquare);
1703 if(gameInfo.variant != VariantSpartan || cl.check == 0) // in Spartan Chess go on to test if other King is checked too
1704 goto undo_move; /* 2-level break */
1711 if(rf != DROP_RANK) // [HGM] drop
1712 board[rf][ff] = board[rt][ft];
1714 board[rf][ft] = captured;
1715 board[rt][ft] = EmptySquare;
1717 if(saveKill >= 0) board[killY][killX = saveKill] = trampled;
1718 board[rt][ft] = captured;
1720 board[EP_STATUS] = ep;
1723 return cl.fking < BOARD_RGHT ? cl.check : 1000; // [HGM] atomic: return 1000 if we have no king
1727 HasLion (Board board, int flags)
1729 int lion = F_WHITE_ON_MOVE & flags ? WhiteLion : BlackLion;
1731 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++)
1732 if(board[r][f] == lion) return 1;
1737 LegalDrop (Board board, int flags, ChessSquare piece, int rt, int ft)
1738 { // [HGM] put drop legality testing in separate routine for clarity
1740 if(appData.debugMode) fprintf(debugFP, "LegalDrop: %d @ %d,%d)\n", piece, ft, rt);
1741 if(board[rt][ft] != EmptySquare) return ImpossibleMove; // must drop to empty square
1742 n = PieceToNumber(piece);
1743 if((gameInfo.holdingsWidth == 0 || (flags & F_WHITE_ON_MOVE ? board[n][BOARD_WIDTH-1] : board[BOARD_HEIGHT-1-n][0]) != piece)
1744 && gameInfo.variant != VariantBughouse) // in bughouse we don't check for availability, because ICS doesn't always tell us
1745 return ImpossibleMove; // piece not available
1746 if(gameInfo.variant == VariantShogi) { // in Shogi lots of drops are forbidden!
1747 if((piece == WhitePawn || piece == WhiteQueen) && rt == BOARD_HEIGHT-1 ||
1748 (piece == BlackPawn || piece == BlackQueen) && rt == 0 ||
1749 piece == WhiteKnight && rt > BOARD_HEIGHT-3 ||
1750 piece == BlackKnight && rt < 2 ) return IllegalMove; // e.g. where dropped piece has no moves
1751 if(piece == WhitePawn || piece == BlackPawn) {
1752 int r, max = 1 + (BOARD_HEIGHT == 7); // two Pawns per file in Tori!
1753 for(r=1; r<BOARD_HEIGHT-1; r++)
1754 if(!(max -= (board[r][ft] == piece))) return IllegalMove; // or there already is a Pawn in file
1755 // should still test if we mate with this Pawn
1757 } else if(gameInfo.variant == VariantSChess) { // only back-rank drops
1758 if (rt != (piece < BlackPawn ? 0 : BOARD_HEIGHT-1)) return IllegalMove;
1760 if( (piece == WhitePawn || piece == BlackPawn) &&
1761 (rt == 0 || rt == BOARD_HEIGHT -1 ) )
1762 return IllegalMove; /* no pawn drops on 1st/8th */
1764 if(appData.debugMode) fprintf(debugFP, "LegalDrop: %d @ %d,%d)\n", piece, ft, rt);
1765 if (!(flags & F_IGNORE_CHECK) &&
1766 CheckTest(board, flags, DROP_RANK, piece, rt, ft, FALSE) ) return IllegalMove;
1767 return flags & F_WHITE_ON_MOVE ? WhiteDrop : BlackDrop;
1770 extern void LegalityTestCallback P((Board board, int flags, ChessMove kind,
1771 int rf, int ff, int rt, int ft,
1775 LegalityTestCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1777 register LegalityTestClosure *cl = (LegalityTestClosure *) closure;
1779 if(board[rt][ft] != EmptySquare || kind==WhiteCapturesEnPassant || kind==BlackCapturesEnPassant)
1780 cl->captures++; // [HGM] losers: count legal captures
1781 if (rf == cl->rf && ff == cl->ff && rt == cl->rt && ft == cl->ft)
1786 LegalityTest (Board board, int flags, int rf, int ff, int rt, int ft, int promoChar)
1788 LegalityTestClosure cl; ChessSquare piece, filterPiece;
1790 if(quickFlag) flags = flags & ~1 | quickFlag & 1; // [HGM] speed: in quick mode quickFlag specifies side-to-move.
1791 if(rf == DROP_RANK) return LegalDrop(board, flags, ff, rt, ft);
1792 piece = filterPiece = board[rf][ff];
1793 if(PieceToChar(piece) == '~') filterPiece = DEMOTED piece;
1795 /* [HGM] Cobra and Falcon are wildcard pieces; consider all their moves legal */
1796 /* (perhaps we should disallow moves that obviously leave us in check?) */
1797 if((piece == WhiteFalcon || piece == BlackFalcon ||
1798 piece == WhiteCobra || piece == BlackCobra) && gameInfo.variant != VariantChu && !pieceDesc[piece])
1799 return CheckTest(board, flags, rf, ff, rt, ft, FALSE) ? IllegalMove : NormalMove;
1803 cl.rt = rFilter = rt; // [HGM] speed: filter on to-square
1804 cl.ft = fFilter = ft;
1805 cl.kind = IllegalMove;
1806 cl.captures = 0; // [HGM] losers: prepare to count legal captures.
1807 if(flags & F_MANDATORY_CAPTURE) filterPiece = EmptySquare; // [HGM] speed: do not filter in suicide, to find all captures
1808 GenLegal(board, flags, LegalityTestCallback, (VOIDSTAR) &cl, filterPiece);
1809 if((flags & F_MANDATORY_CAPTURE) && cl.captures && board[rt][ft] == EmptySquare
1810 && cl.kind != WhiteCapturesEnPassant && cl.kind != BlackCapturesEnPassant)
1811 return(IllegalMove); // [HGM] losers: if there are legal captures, non-capts are illegal
1813 if(promoChar == 'x') promoChar = NULLCHAR; // [HGM] is this ever the case?
1814 if(gameInfo.variant == VariantSChess && promoChar && promoChar != '=' && board[rf][ff] != WhitePawn && board[rf][ff] != BlackPawn) {
1815 if(board[rf][ff] < BlackPawn) { // white
1816 if(rf != 0) return IllegalMove; // must be on back rank
1817 if(!(board[VIRGIN][ff] & VIRGIN_W)) return IllegalMove; // non-virgin
1818 if(board[PieceToNumber(CharToPiece(ToUpper(promoChar)))][BOARD_WIDTH-2] == 0) return ImpossibleMove;// must be in stock
1819 if(cl.kind == WhiteHSideCastleFR && (ff == BOARD_RGHT-2 || ff == BOARD_RGHT-3)) return ImpossibleMove;
1820 if(cl.kind == WhiteASideCastleFR && (ff == BOARD_LEFT+2 || ff == BOARD_LEFT+3)) return ImpossibleMove;
1822 if(rf != BOARD_HEIGHT-1) return IllegalMove;
1823 if(!(board[VIRGIN][ff] & VIRGIN_B)) return IllegalMove; // non-virgin
1824 if(board[BOARD_HEIGHT-1-PieceToNumber(CharToPiece(ToLower(promoChar)))][1] == 0) return ImpossibleMove;
1825 if(cl.kind == BlackHSideCastleFR && (ff == BOARD_RGHT-2 || ff == BOARD_RGHT-3)) return ImpossibleMove;
1826 if(cl.kind == BlackASideCastleFR && (ff == BOARD_LEFT+2 || ff == BOARD_LEFT+3)) return ImpossibleMove;
1829 if(gameInfo.variant == VariantChu) {
1830 if(cl.kind != NormalMove || promoChar == NULLCHAR || promoChar == '=') return cl.kind;
1831 if(promoChar != '+')
1832 return CharToPiece(promoChar) == EmptySquare ? ImpossibleMove : IllegalMove;
1833 if(PieceToChar(CHUPROMOTED board[rf][ff]) != '+') {
1834 if(PieceToChar(CHUPROMOTED (board[rf][ff] < BlackPawn ? WhitePawn : BlackPawn)) != '.')
1835 return ImpossibleMove;
1837 return flags & F_WHITE_ON_MOVE ? WhitePromotion : BlackPromotion;
1839 if(gameInfo.variant == VariantShogi) {
1840 /* [HGM] Shogi promotions. '=' means defer */
1841 if(rf != DROP_RANK && cl.kind == NormalMove) {
1842 ChessSquare piece = board[rf][ff];
1843 int zone = BOARD_HEIGHT/3 + (BOARD_HEIGHT == 8);
1845 if(promoChar == PieceToChar(BlackQueen)) promoChar = NULLCHAR; /* [HGM] Kludge */
1846 if(promoChar == 'd' && (piece == WhiteRook || piece == BlackRook) ||
1847 promoChar == 'h' && (piece == WhiteBishop || piece == BlackBishop) ||
1848 promoChar == 'g' && (piece <= WhiteFerz || piece <= BlackFerz && piece >= BlackPawn) )
1849 promoChar = '+'; // allowed ICS notations
1850 if(appData.debugMode)fprintf(debugFP,"SHOGI promoChar = %c\n", promoChar ? promoChar : '-');
1851 if(promoChar != NULLCHAR && promoChar != '+' && promoChar != '=')
1852 return CharToPiece(promoChar) == EmptySquare ? ImpossibleMove : IllegalMove;
1853 else if(flags & F_WHITE_ON_MOVE) {
1854 if( (int) piece < (int) WhiteWazir &&
1855 (rf >= BOARD_HEIGHT - zone || rt >= BOARD_HEIGHT - zone) ) {
1856 if( (piece == WhitePawn || piece == WhiteQueen) && rt > BOARD_HEIGHT-2 ||
1857 piece == WhiteKnight && rt > BOARD_HEIGHT-3) /* promotion mandatory */
1858 cl.kind = promoChar == '=' ? IllegalMove : WhitePromotion;
1859 else /* promotion optional, default is defer */
1860 cl.kind = promoChar == '+' ? WhitePromotion : WhiteNonPromotion;
1861 } else cl.kind = promoChar == '+' ? IllegalMove : NormalMove;
1863 if( (int) piece < (int) BlackWazir && (rf < zone || rt < zone) ) {
1864 if( (piece == BlackPawn || piece == BlackQueen) && rt < 1 ||
1865 piece == BlackKnight && rt < 2 ) /* promotion obligatory */
1866 cl.kind = promoChar == '=' ? IllegalMove : BlackPromotion;
1867 else /* promotion optional, default is defer */
1868 cl.kind = promoChar == '+' ? BlackPromotion : BlackNonPromotion;
1869 } else cl.kind = promoChar == '+' ? IllegalMove : NormalMove;
1873 if (promoChar != NULLCHAR) {
1874 if(cl.kind == NormalMove && promoChar == '+') { // allow shogi-style promotion is pieceToChar specifies them
1875 ChessSquare piece = board[rf][ff];
1876 if(piece < BlackPawn ? piece > WhiteMan : piece > BlackMan) return ImpossibleMove; // already promoted
1877 // should test if in zone, really
1878 if(gameInfo.variant == VariantChuChess && (piece == WhiteKnight || piece == BlackKnight) && HasLion(board, flags))
1880 if(PieceToChar(PROMOTED piece) == '+') return flags & F_WHITE_ON_MOVE ? WhitePromotion : BlackPromotion;
1882 if(promoChar == '=') cl.kind = IllegalMove; else // [HGM] shogi: no deferred promotion outside Shogi
1883 if (cl.kind == WhitePromotion || cl.kind == BlackPromotion) {
1884 ChessSquare piece = CharToPiece(flags & F_WHITE_ON_MOVE ? ToUpper(promoChar) : ToLower(promoChar));
1885 if(piece == EmptySquare)
1886 cl.kind = ImpossibleMove; // non-existing piece
1887 if(gameInfo.variant == VariantChuChess && promoChar == 'l' && HasLion(board, flags)) {
1888 cl.kind = IllegalMove; // no two Lions
1889 } else if(gameInfo.variant == VariantSpartan && cl.kind == BlackPromotion ) {
1890 if(promoChar != PieceToChar(BlackKing)) {
1891 if(CheckTest(board, flags, rf, ff, rt, ft, FALSE)) cl.kind = IllegalMove; // [HGM] spartan: only promotion to King was possible
1892 if(piece == BlackLance) cl.kind = ImpossibleMove;
1893 } else { // promotion to King allowed only if we do not have two yet
1894 int r, f, kings = 0;
1895 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++) kings += (board[r][f] == BlackKing);
1896 if(kings == 2) cl.kind = IllegalMove;
1898 } else if(piece == WhitePawn && rt == BOARD_HEIGHT-1 ||
1899 piece == BlackPawn && rt == 0) cl.kind = IllegalMove; // cannot stay Pawn on last rank in any variant
1900 else if((piece == WhiteUnicorn || piece == BlackUnicorn) && gameInfo.variant == VariantKnightmate)
1901 cl.kind = IllegalMove; // promotion to Royal Knight not allowed
1902 else if((piece == WhiteKing || piece == BlackKing) && gameInfo.variant != VariantSuicide && gameInfo.variant != VariantGiveaway)
1903 cl.kind = IllegalMove; // promotion to King usually not allowed
1905 cl.kind = IllegalMove;
1915 extern void MateTestCallback P((Board board, int flags, ChessMove kind,
1916 int rf, int ff, int rt, int ft,
1920 MateTestCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1922 register MateTestClosure *cl = (MateTestClosure *) closure;
1927 /* Return MT_NONE, MT_CHECK, MT_CHECKMATE, or MT_STALEMATE */
1929 MateTest (Board board, int flags)
1932 int inCheck, r, f, myPieces=0, hisPieces=0, nrKing=0;
1933 ChessSquare king = flags & F_WHITE_ON_MOVE ? WhiteKing : BlackKing;
1935 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++) {
1936 // [HGM] losers: Count pieces and kings, to detect other unorthodox winning conditions
1937 nrKing += (board[r][f] == king); // stm has king
1938 if( board[r][f] != EmptySquare ) {
1939 if((int)board[r][f] <= (int)king && (int)board[r][f] >= (int)king - (int)WhiteKing + (int)WhitePawn)
1944 switch(gameInfo.variant) { // [HGM] losers: extinction wins
1945 case VariantShatranj:
1946 if(hisPieces == 1) return myPieces > 1 ? MT_BARE : MT_DRAW;
1950 if(nrKing == 0) return MT_NOKING;
1953 if(myPieces == 1) return MT_BARE;
1956 inCheck = GenLegal(board, flags, MateTestCallback, (VOIDSTAR) &cl, EmptySquare);
1957 // [HGM] 3check: yet to do!
1959 return inCheck ? MT_CHECK : MT_NONE;
1961 if(gameInfo.holdingsWidth && gameInfo.variant != VariantSuper && gameInfo.variant != VariantGreat
1962 && gameInfo.variant != VariantSChess && gameInfo.variant != VariantGrand) { // drop game
1963 int r, f, n, holdings = flags & F_WHITE_ON_MOVE ? BOARD_WIDTH-1 : 0;
1964 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++) if(board[r][f] == EmptySquare) // all empty squares
1965 for(n=0; n<BOARD_HEIGHT; n++) // all pieces in hand
1966 if(board[n][holdings] != EmptySquare) {
1967 int moveType = LegalDrop(board, flags, board[n][holdings], r, f);
1968 if(moveType == WhiteDrop || moveType == BlackDrop) return (inCheck ? MT_CHECK : MT_NONE); // we have legal drop
1971 if(gameInfo.variant == VariantSuicide) // [HGM] losers: always stalemate, since no check, but result varies
1972 return myPieces == hisPieces ? MT_STALEMATE :
1973 myPieces > hisPieces ? MT_STAINMATE : MT_STEALMATE;
1974 else if(gameInfo.variant == VariantLosers) return inCheck ? MT_TRICKMATE : MT_STEALMATE;
1975 else if(gameInfo.variant == VariantGiveaway) return MT_STEALMATE; // no check exists, stalemated = win
1977 return inCheck ? MT_CHECKMATE
1978 : (gameInfo.variant == VariantXiangqi || gameInfo.variant == VariantShatranj || IS_SHOGI(gameInfo.variant)) ?
1979 MT_STAINMATE : MT_STALEMATE;
1984 extern void DisambiguateCallback P((Board board, int flags, ChessMove kind,
1985 int rf, int ff, int rt, int ft,
1989 DisambiguateCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1991 register DisambiguateClosure *cl = (DisambiguateClosure *) closure;
1992 int wildCard = FALSE; ChessSquare piece = board[rf][ff];
1993 extern int kifu; // in parser.c
1995 // [HGM] wild: for wild-card pieces rt and rf are dummies
1996 if(piece == WhiteFalcon || piece == BlackFalcon ||
1997 piece == WhiteCobra || piece == BlackCobra)
2000 if ((cl->pieceIn == EmptySquare || cl->pieceIn == board[rf][ff]
2001 || PieceToChar(board[rf][ff]) == '~'
2002 && cl->pieceIn == (ChessSquare)(DEMOTED board[rf][ff])
2004 (cl->rfIn == -1 || cl->rfIn == rf) &&
2005 (cl->ffIn == -1 || cl->ffIn == ff) &&
2006 (cl->rtIn == -1 || cl->rtIn == rt || wildCard) &&
2007 (cl->ftIn == -1 || cl->ftIn == ft || wildCard)) {
2009 if(cl->count && rf == cl->rf && ff == cl->ff) return; // duplicate move
2011 if(cl->count == 1 && kifu & 0x7E && cl->rfIn == -1 && cl->ffIn == -1) { // traditional Shogi disambiguation required
2012 int this = 1, other = 1;
2013 if(kifu & 2) this &= (flags & 1 ? rt > rf : rt < rf), other &= (flags & 1 ? cl->rt > cl->rf : cl->rt < cl->rf);
2014 if(kifu & 4) this &= (flags & 1 ? rt < rf : rt > rf), other &= (flags & 1 ? cl->rt < cl->rf : cl->rt > cl->rf);
2015 if(kifu & 8) this &= (rf == rt), other &= (cl->rt == cl->rf);
2016 if(kifu & 0x10) this &= (flags & 1 ? ft <= ff : ft >= ff), other &= (flags & 1 ? cl->ft <= cl->ff : cl->ft >= cl->ff);
2017 if(kifu & 0x20) this &= (flags & 1 ? ft >= ff : ft <= ff), other &= (flags & 1 ? cl->ft >= cl->ff : cl->ft <= cl->ff);
2018 if(kifu & 0x40) this &= (ft == ff), other &= (cl->ft == cl->ff); // should never be used
2019 if(!other) cl->count--; // the old move did not satisfy the requested relative position, erase it
2020 if(!this) return; // the current move does not satisfy the requested relative position, ignore it
2024 if(cl->count == 1 || board[rt][ft] != EmptySquare) {
2025 // [HGM] oneclick: if multiple moves, be sure we remember capture
2026 cl->piece = board[rf][ff];
2029 cl->rt = wildCard ? cl->rtIn : rt;
2030 cl->ft = wildCard ? cl->ftIn : ft;
2033 cl->captures += (board[rt][ft] != EmptySquare); // [HGM] oneclick: count captures
2038 Disambiguate (Board board, int flags, DisambiguateClosure *closure)
2040 int illegal = 0; char c = closure->promoCharIn;
2042 if(quickFlag) flags = flags & ~1 | quickFlag & 1; // [HGM] speed: in quick mode quickFlag specifies side-to-move.
2043 closure->count = closure->captures = 0;
2044 closure->rf = closure->ff = closure->rt = closure->ft = 0;
2045 closure->kind = ImpossibleMove;
2046 rFilter = closure->rtIn; // [HGM] speed: only consider moves to given to-square
2047 fFilter = closure->ftIn;
2048 if(quickFlag) { // [HGM] speed: try without check test first, because if that is not ambiguous, we are happy
2049 GenLegal(board, flags|F_IGNORE_CHECK, DisambiguateCallback, (VOIDSTAR) closure, closure->pieceIn);
2050 if(closure->count > 1) { // gamble did not pay off. retry with check test to resolve ambiguity
2051 closure->count = closure->captures = 0;
2052 closure->rf = closure->ff = closure->rt = closure->ft = 0;
2053 closure->kind = ImpossibleMove;
2054 GenLegal(board, flags, DisambiguateCallback, (VOIDSTAR) closure, closure->pieceIn); // [HGM] speed: only pieces of requested type
2057 GenLegal(board, flags, DisambiguateCallback, (VOIDSTAR) closure, closure->pieceIn); // [HGM] speed: only pieces of requested type
2058 if (closure->count == 0) {
2059 /* See if it's an illegal move due to check */
2061 GenLegal(board, flags|F_IGNORE_CHECK, DisambiguateCallback, (VOIDSTAR) closure, closure->pieceIn);
2062 if (closure->count == 0) {
2063 /* No, it's not even that */
2064 if(!appData.testLegality && !pieceDefs && closure->pieceIn != EmptySquare) {
2065 int f, r; // if there is only a single piece of the requested type on the board, use that
2066 closure->rt = closure->rtIn, closure->ft = closure->ftIn;
2067 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++)
2068 if(board[r][f] == closure->pieceIn) closure->count++, closure->rf = r, closure->ff = f;
2069 if(closure->count > 1) illegal = 0; // ambiguous
2071 if(closure->count == 0) {
2072 if (appData.debugMode) { int i, j;
2073 for(i=BOARD_HEIGHT-1; i>=0; i--) {
2074 for(j=0; j<BOARD_WIDTH; j++)
2075 fprintf(debugFP, "%3d", (int) board[i][j]);
2076 fprintf(debugFP, "\n");
2082 } else if(pieceDefs && closure->count > 1) { // [HGM] gen: move is ambiguous under engine-defined rules
2083 DisambiguateClosure spare = *closure;
2084 pieceDefs = FALSE; spare.count = 0; // See if the (erroneous) built-in rules would resolve that
2085 GenLegal(board, flags, DisambiguateCallback, (VOIDSTAR) &spare, closure->pieceIn);
2086 if(spare.count == 1) *closure = spare; // It does, so use those in stead (game from file saved before gen patch?)
2090 if (c == 'x') c = NULLCHAR; // get rid of any 'x' (which should never happen?)
2091 if(gameInfo.variant == VariantSChess && c && c != '=' && closure->piece != WhitePawn && closure->piece != BlackPawn) {
2092 if(closure->piece < BlackPawn) { // white
2093 if(closure->rf != 0) closure->kind = IllegalMove; // must be on back rank
2094 if(!(board[VIRGIN][closure->ff] & VIRGIN_W)) closure->kind = IllegalMove; // non-virgin
2095 if(board[PieceToNumber(CharToPiece(ToUpper(c)))][BOARD_WIDTH-2] == 0) closure->kind = ImpossibleMove;// must be in stock
2096 if(closure->kind == WhiteHSideCastleFR && (closure->ff == BOARD_RGHT-2 || closure->ff == BOARD_RGHT-3)) closure->kind = ImpossibleMove;
2097 if(closure->kind == WhiteASideCastleFR && (closure->ff == BOARD_LEFT+2 || closure->ff == BOARD_LEFT+3)) closure->kind = ImpossibleMove;
2099 if(closure->rf != BOARD_HEIGHT-1) closure->kind = IllegalMove;
2100 if(!(board[VIRGIN][closure->ff] & VIRGIN_B)) closure->kind = IllegalMove; // non-virgin
2101 if(board[BOARD_HEIGHT-1-PieceToNumber(CharToPiece(ToLower(c)))][1] == 0) closure->kind = ImpossibleMove;
2102 if(closure->kind == BlackHSideCastleFR && (closure->ff == BOARD_RGHT-2 || closure->ff == BOARD_RGHT-3)) closure->kind = ImpossibleMove;
2103 if(closure->kind == BlackASideCastleFR && (closure->ff == BOARD_LEFT+2 || closure->ff == BOARD_LEFT+3)) closure->kind = ImpossibleMove;
2106 if(gameInfo.variant == VariantChu) {
2107 if(c == '+') closure->kind = (flags & F_WHITE_ON_MOVE ? WhitePromotion : BlackPromotion); // for now, accept any
2109 if(gameInfo.variant == VariantShogi) {
2110 /* [HGM] Shogi promotions. On input, '=' means defer, '+' promote. Afterwards, c is set to '+' for promotions, NULL other */
2111 if(closure->rfIn != DROP_RANK && closure->kind == NormalMove) {
2112 ChessSquare piece = closure->piece;
2113 int zone = BOARD_HEIGHT/3 + (BOARD_HEIGHT == 8);
2114 if (c == 'd' && (piece == WhiteRook || piece == BlackRook) ||
2115 c == 'h' && (piece == WhiteBishop || piece == BlackBishop) ||
2116 c == 'g' && (piece <= WhiteFerz || piece <= BlackFerz && piece >= BlackPawn) )
2117 c = '+'; // allowed ICS notations
2118 if(c != NULLCHAR && c != '+' && c != '=') closure->kind = IllegalMove; // otherwise specifying a piece is illegal
2119 else if(flags & F_WHITE_ON_MOVE) {
2120 if( (int) piece < (int) WhiteWazir &&
2121 (closure->rf >= BOARD_HEIGHT-zone || closure->rt >= BOARD_HEIGHT-zone) ) {
2122 if( (piece == WhitePawn || piece == WhiteQueen) && closure->rt > BOARD_HEIGHT-2 ||
2123 piece == WhiteKnight && closure->rt > BOARD_HEIGHT-3) /* promotion mandatory */
2124 closure->kind = c == '=' ? IllegalMove : WhitePromotion;
2125 else /* promotion optional, default is defer */
2126 closure->kind = c == '+' ? WhitePromotion : WhiteNonPromotion;
2127 } else closure->kind = c == '+' ? IllegalMove : NormalMove;
2129 if( (int) piece < (int) BlackWazir && (closure->rf < zone || closure->rt < zone) ) {
2130 if( (piece == BlackPawn || piece == BlackQueen) && closure->rt < 1 ||
2131 piece == BlackKnight && closure->rt < 2 ) /* promotion obligatory */
2132 closure->kind = c == '=' ? IllegalMove : BlackPromotion;
2133 else /* promotion optional, default is defer */
2134 closure->kind = c == '+' ? BlackPromotion : BlackNonPromotion;
2135 } else closure->kind = c == '+' ? IllegalMove : NormalMove;
2138 if(closure->kind == WhitePromotion || closure->kind == BlackPromotion) c = '+'; else
2139 if(closure->kind == WhiteNonPromotion || closure->kind == BlackNonPromotion) c = '=';
2141 if (closure->kind == WhitePromotion || closure->kind == BlackPromotion) {
2142 if(c == NULLCHAR) { // missing promoChar on mandatory promotion; use default for variant
2143 if(gameInfo.variant == VariantShatranj || gameInfo.variant == VariantCourier ||
2144 gameInfo.variant == VariantMakruk)
2145 c = PieceToChar(BlackFerz);
2146 else if(gameInfo.variant == VariantASEAN)
2147 c = PieceToChar(BlackRook);
2148 else if(gameInfo.variant == VariantGreat)
2149 c = PieceToChar(BlackMan);
2150 else if(gameInfo.variant == VariantGrand)
2151 closure->kind = closure->rt != 0 && closure->rt != BOARD_HEIGHT-1 ? NormalMove : AmbiguousMove; // no default in Grand Chess
2153 c = PieceToChar(BlackQueen);
2154 } else if(c == '=') closure->kind = IllegalMove; // no deferral outside Shogi
2155 else if(c == 'l' && gameInfo.variant == VariantChuChess && HasLion(board, flags)) closure->kind = IllegalMove;
2156 } else if (c == '+') { // '+' outside shogi, check if pieceToCharTable enabled it
2157 ChessSquare p = closure->piece;
2158 if(p > WhiteMan && p < BlackPawn || p > BlackMan || PieceToChar(PROMOTED p) != '+')
2159 closure->kind = ImpossibleMove; // used on non-promotable piece
2160 else if(gameInfo.variant == VariantChuChess && HasLion(board, flags)) closure->kind = IllegalMove;
2161 } else if (c != NULLCHAR) closure->kind = IllegalMove;
2163 closure->promoChar = ToLower(c); // this can be NULLCHAR! Note we keep original promoChar even if illegal.
2164 if(c != '+' && c != '=' && c != NULLCHAR && CharToPiece(flags & F_WHITE_ON_MOVE ? ToUpper(c) : ToLower(c)) == EmptySquare)
2165 closure->kind = ImpossibleMove; // but we cannot handle non-existing piece types!
2166 if (closure->count > 1) {
2167 closure->kind = AmbiguousMove;
2170 /* Note: If more than one illegal move matches, but no legal
2171 moves, we return IllegalMove, not AmbiguousMove. Caller
2172 can look at closure->count to detect this.
2174 closure->kind = IllegalMove;
2188 } CoordsToAlgebraicClosure;
2190 extern void CoordsToAlgebraicCallback P((Board board, int flags,
2191 ChessMove kind, int rf, int ff,
2192 int rt, int ft, VOIDSTAR closure));
2195 CoordsToAlgebraicCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
2197 register CoordsToAlgebraicClosure *cl =
2198 (CoordsToAlgebraicClosure *) closure;
2200 if ((rt == cl->rt && ft == cl->ft || rt == rf && ft == ff) && // [HGM] null move matches any toSquare
2201 (board[rf][ff] == cl->piece
2202 || PieceToChar(board[rf][ff]) == '~' &&
2203 (ChessSquare) (DEMOTED board[rf][ff]) == cl->piece)
2207 cl->kind = kind; /* this is the move we want */
2209 cl->file++; /* need file to rule out this move */
2213 cl->rank++; /* need rank to rule out this move */
2215 cl->either++; /* rank or file will rule out this move */
2221 /* Convert coordinates to normal algebraic notation.
2222 promoChar must be NULLCHAR or 'x' if not a promotion.
2225 CoordsToAlgebraic (Board board, int flags, int rf, int ff, int rt, int ft, int promoChar, char out[MOVE_LEN])
2229 char *outp = out, c, capture;
2230 CoordsToAlgebraicClosure cl;
2232 if (rf == DROP_RANK) {
2233 if(ff == EmptySquare) { strncpy(outp, "--",3); return NormalMove; } // [HGM] pass
2234 /* Bughouse piece drop */
2235 *outp++ = ToUpper(PieceToChar((ChessSquare) ff));
2240 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2242 return (flags & F_WHITE_ON_MOVE) ? WhiteDrop : BlackDrop;
2245 if (promoChar == 'x') promoChar = NULLCHAR;
2246 piece = board[rf][ff];
2247 if(PieceToChar(piece)=='~') piece = (ChessSquare)(DEMOTED piece);
2252 kind = LegalityTest(board, flags, rf, ff, rt, ft, promoChar);
2253 if (kind == IllegalMove && !(flags&F_IGNORE_CHECK)) {
2254 /* Keep short notation if move is illegal only because it
2255 leaves the player in check, but still return IllegalMove */
2256 kind = LegalityTest(board, flags|F_IGNORE_CHECK, rf, ff, rt, ft, promoChar);
2257 if (kind == IllegalMove) break;
2262 capture = board[rt][ft] != EmptySquare || kind == WhiteCapturesEnPassant || kind == BlackCapturesEnPassant;
2263 if (ff == ft && !capture) { /* [HGM] Xiangqi has straight noncapts! */
2264 /* Non-capture; use style "e5" */
2267 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2269 /* Capture; use style "exd5" */
2271 *outp++ = 'x'; /* [HGM] Xiangqi has sideway noncaptures across river! */
2275 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2277 /* Use promotion suffix style "=Q" */
2279 if (promoChar != NULLCHAR) {
2280 if(IS_SHOGI(gameInfo.variant)) {
2281 /* [HGM] ... but not in Shogi! */
2282 *outp++ = promoChar == '=' ? '=' : '+';
2285 *outp++ = ToUpper(promoChar);
2294 /* Fabien moved code: FRC castling first (if KxR), wild castling second */
2295 /* Code added by Tord: FRC castling. */
2296 if((piece == WhiteKing && board[rt][ft] == WhiteRook) ||
2297 (piece == BlackKing && board[rt][ft] == BlackRook)) {
2299 safeStrCpy(out, "O-O", MOVE_LEN);
2301 safeStrCpy(out, "O-O-O", MOVE_LEN);
2302 return LegalityTest(board, flags, rf, ff, rt, ft, promoChar);
2304 /* End of code added by Tord */
2305 /* Test for castling or ICS wild castling */
2306 /* Use style "O-O" (oh-oh) for PGN compatibility */
2307 else if (rf == rt &&
2308 rf == ((piece == WhiteKing) ? 0 : BOARD_HEIGHT-1) &&
2309 (ft - ff > 1 || ff - ft > 1) && // No castling if legal King move (on narrow boards!)
2310 ((ff == BOARD_WIDTH>>1 && (ft == BOARD_LEFT+2 || ft == BOARD_RGHT-2)) ||
2311 (ff == (BOARD_WIDTH-1)>>1 && (ft == BOARD_LEFT+1 || ft == BOARD_RGHT-3)))) {
2312 if(ft==BOARD_LEFT+1 || ft==BOARD_RGHT-2)
2313 snprintf(out, MOVE_LEN, "O-O%c%c", promoChar ? '/' : 0, ToUpper(promoChar));
2315 snprintf(out, MOVE_LEN, "O-O-O%c%c", promoChar ? '/' : 0, ToUpper(promoChar));
2317 /* This notation is always unambiguous, unless there are
2318 kings on both the d and e files, with "wild castling"
2319 possible for the king on the d file and normal castling
2320 possible for the other. ICS rules for wild 9
2321 effectively make castling illegal for either king in
2322 this situation. So I am not going to worry about it;
2323 I'll just generate an ambiguous O-O in this case.
2325 return LegalityTest(board, flags, rf, ff, rt, ft, promoChar);
2328 /* else fall through */
2333 cl.rt = rFilter = rt; // [HGM] speed: filter on to-square
2334 cl.ft = fFilter = ft;
2336 cl.kind = IllegalMove;
2337 cl.rank = cl.file = cl.either = 0;
2338 c = PieceToChar(piece) ;
2339 GenLegal(board, flags, CoordsToAlgebraicCallback, (VOIDSTAR) &cl, c!='~' ? piece : (DEMOTED piece)); // [HGM] speed
2341 if (cl.kind == IllegalMove && !(flags&F_IGNORE_CHECK)) {
2342 /* Generate pretty moves for moving into check, but
2343 still return IllegalMove.
2345 GenLegal(board, flags|F_IGNORE_CHECK, CoordsToAlgebraicCallback, (VOIDSTAR) &cl, c!='~' ? piece : (DEMOTED piece));
2346 if (cl.kind == IllegalMove) break;
2347 cl.kind = IllegalMove;
2350 /* Style is "Nf3" or "Nxf7" if this is unambiguous,
2351 else "Ngf3" or "Ngxf7",
2352 else "N1f3" or "N5xf7",
2353 else "Ng1f3" or "Ng5xf7".
2355 if( c == '~' || c == '+') {
2356 /* [HGM] print nonexistent piece as its demoted version */
2357 piece = (ChessSquare) (DEMOTED piece - 11*(gameInfo.variant == VariantChu));
2359 if(c=='+') *outp++ = c;
2360 *outp++ = ToUpper(PieceToChar(piece));
2361 if(*outp = PieceSuffix(piece)) outp++;
2363 if (cl.file || (cl.either && !cl.rank)) {
2369 else { *outp++ = (rf+ONE-'0')/10 + '0';*outp++ = (rf+ONE-'0')%10 + '0'; }
2372 if(board[rt][ft] != EmptySquare)
2378 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2379 if (IS_SHOGI(gameInfo.variant)) {
2380 /* [HGM] in Shogi non-pawns can promote */
2381 *outp++ = promoChar; // Don't bother to correct move type, return value is never used!
2383 else if (gameInfo.variant == VariantChuChess && promoChar ||
2384 gameInfo.variant != VariantSuper && promoChar &&
2385 (piece == WhiteLance || piece == BlackLance) ) { // Lance sometimes represents Pawn
2387 *outp++ = ToUpper(promoChar);
2389 else if (gameInfo.variant == VariantSChess && promoChar) { // and in S-Chess we have gating
2391 *outp++ = ToUpper(promoChar);
2397 /* Moving a nonexistent piece */
2401 /* Not a legal move, even ignoring check.
2402 If there was a piece on the from square,
2403 use style "Ng1g3" or "Ng1xe8";
2404 if there was a pawn or nothing (!),
2405 use style "g1g3" or "g1xe8". Use "x"
2406 if a piece was on the to square, even
2407 a piece of the same color.
2411 if (piece != EmptySquare && piece != WhitePawn && piece != BlackPawn) {
2413 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<=BOARD_RGHT; f++)
2414 c += (board[r][f] == piece); // count on-board pieces of given type
2415 *outp++ = ToUpper(PieceToChar(piece));
2417 if(c != 1) { // [HGM] but if there is only one piece of the mentioned type, no from-square, thank you!
2421 else { *outp++ = (rf+ONE-'0')/10 + '0';*outp++ = (rf+ONE-'0')%10 + '0'; }
2423 if (board[rt][ft] != EmptySquare) *outp++ = 'x';
2427 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2428 /* Use promotion suffix style "=Q" */
2429 if (promoChar != NULLCHAR && promoChar != 'x') {
2431 *outp++ = ToUpper(promoChar);
2438 // [HGM] XQ: the following code serves to detect perpetual chasing (Asian rules)
2447 // I guess the following variables logically belong in the closure too, but I was too lazy and used globals
2449 int preyStackPointer, chaseStackPointer;
2452 unsigned char rf, ff, rt, ft;
2456 unsigned char rank, file;
2462 // there are three new callbacks for use with GenLegal: for adding captures, deleting them, and finding a recapture
2464 extern void AtacksCallback P((Board board, int flags, ChessMove kind,
2465 int rf, int ff, int rt, int ft,
2469 AttacksCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
2470 { // For adding captures that can lead to chase indictment to the chaseStack
2471 if(board[rt][ft] == EmptySquare) return; // non-capture
2472 if(board[rt][ft] == WhitePawn && rt < BOARD_HEIGHT/2) return; // Pawn before river can be chased
2473 if(board[rt][ft] == BlackPawn && rt >= BOARD_HEIGHT/2) return; // Pawn before river can be chased
2474 if(board[rf][ff] == WhitePawn || board[rf][ff] == BlackPawn) return; // Pawns are allowed to chase
2475 if(board[rf][ff] == WhiteWazir || board[rf][ff] == BlackWazir) return; // King is allowed to chase
2476 // move cannot be excluded from being a chase trivially (based on attacker and victim); save it on chaseStack
2477 chaseStack[chaseStackPointer].rf = rf;
2478 chaseStack[chaseStackPointer].ff = ff;
2479 chaseStack[chaseStackPointer].rt = rt;
2480 chaseStack[chaseStackPointer].ft = ft;
2481 chaseStackPointer++;
2484 extern void ExistingAtacksCallback P((Board board, int flags, ChessMove kind,
2485 int rf, int ff, int rt, int ft,
2489 ExistingAttacksCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
2490 { // for removing pre-exsting captures from the chaseStack, to be left with newly created ones
2492 register ChaseClosure *cl = (ChaseClosure *) closure; //closure tells us the move played in the repeat loop
2494 if(board[rt][ft] == EmptySquare) return; // no capture
2495 if(rf == cl->rf && ff == cl->ff) { // attacks with same piece from new position are not considered new
2496 rf = cl->rt; ff = cl->ft; // doctor their fromSquare so they will be recognized in chaseStack
2498 // search move in chaseStack, and delete it if it occurred there (as we know now it is not a new capture)
2499 for(i=0; i<chaseStackPointer; i++) {
2500 if(chaseStack[i].rf == rf && chaseStack[i].ff == ff &&
2501 chaseStack[i].rt == rt && chaseStack[i].ft == ft ) {
2502 // move found on chaseStack, delete it by overwriting with move popped from top of chaseStack
2503 chaseStack[i] = chaseStack[--chaseStackPointer];
2509 extern void ProtectedCallback P((Board board, int flags, ChessMove kind,
2510 int rf, int ff, int rt, int ft,
2514 ProtectedCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
2515 { // for determining if a piece (given through the closure) is protected
2516 register ChaseClosure *cl = (ChaseClosure *) closure; // closure tells us where to recapture
2518 if(rt == cl->rt && ft == cl->ft) cl->recaptures++; // count legal recaptures to this square
2519 if(appData.debugMode && board[rt][ft] != EmptySquare)
2520 fprintf(debugFP, "try %c%c%c%c=%d\n", ff+AAA, rf+ONE,ft+AAA, rt+ONE, cl->recaptures);
2523 extern char moveList[MAX_MOVES][MOVE_LEN];
2526 PerpetualChase (int first, int last)
2527 { // this routine detects if the side to move in the 'first' position is perpetually chasing (when not checking)
2530 ChessSquare captured;
2532 preyStackPointer = 0; // clear stack of chased pieces
2533 for(i=first; i<last; i+=2) { // for all positions with same side to move
2534 if(appData.debugMode) fprintf(debugFP, "judge position %i\n", i);
2535 chaseStackPointer = 0; // clear stack that is going to hold possible chases
2536 // determine all captures possible after the move, and put them on chaseStack
2537 GenLegal(boards[i+1], PosFlags(i), AttacksCallback, &cl, EmptySquare);
2538 if(appData.debugMode) { int n;
2539 for(n=0; n<chaseStackPointer; n++)
2540 fprintf(debugFP, "%c%c%c%c ", chaseStack[n].ff+AAA, chaseStack[n].rf+ONE,
2541 chaseStack[n].ft+AAA, chaseStack[n].rt+ONE);
2542 fprintf(debugFP, ": all capts\n");
2544 // determine all captures possible before the move, and delete them from chaseStack
2545 cl.rf = moveList[i][1]-ONE; // prepare closure to pass move that led from i to i+1
2546 cl.ff = moveList[i][0]-AAA+BOARD_LEFT;
2547 cl.rt = moveList[i][3]-ONE;
2548 cl.ft = moveList[i][2]-AAA+BOARD_LEFT;
2549 CopyBoard(xqCheckers, nullBoard); xqCheckers[EP_STATUS] = 1; // giant kludge to make GenLegal ignore pre-existing checks
2550 GenLegal(boards[i], PosFlags(i), ExistingAttacksCallback, &cl, EmptySquare);
2551 xqCheckers[EP_STATUS] = 0; // disable the generation of quasi-legal moves again
2552 if(appData.debugMode) { int n;
2553 for(n=0; n<chaseStackPointer; n++)
2554 fprintf(debugFP, "%c%c%c%c ", chaseStack[n].ff+AAA, chaseStack[n].rf+ONE,
2555 chaseStack[n].ft+AAA, chaseStack[n].rt+ONE);
2556 fprintf(debugFP, ": new capts after %c%c%c%c\n", cl.ff+AAA, cl.rf+ONE, cl.ft+AAA, cl.rt+ONE);
2558 // chaseSack now contains all captures made possible by the move
2559 for(j=0; j<chaseStackPointer; j++) { // run through chaseStack to identify true chases
2560 int attacker = (int)boards[i+1][chaseStack[j].rf][chaseStack[j].ff];
2561 int victim = (int)boards[i+1][chaseStack[j].rt][chaseStack[j].ft];
2563 if(attacker >= (int) BlackPawn) attacker = BLACK_TO_WHITE attacker; // convert to white, as piecee type
2564 if(victim >= (int) BlackPawn) victim = BLACK_TO_WHITE victim;
2566 if((attacker == WhiteKnight || attacker == WhiteCannon) && victim == WhiteRook)
2567 continue; // C or H attack on R is always chase; leave on chaseStack
2569 if(attacker == victim) {
2570 if(LegalityTest(boards[i+1], PosFlags(i+1), chaseStack[j].rt,
2571 chaseStack[j].ft, chaseStack[j].rf, chaseStack[j].ff, NULLCHAR) == NormalMove) {
2572 // we can capture back with equal piece, so this is no chase but a sacrifice
2573 chaseStack[j] = chaseStack[--chaseStackPointer]; // delete the capture from the chaseStack
2574 j--; /* ! */ continue;
2579 // the attack is on a lower piece, or on a pinned or blocked equal one
2580 CopyBoard(xqCheckers, nullBoard); xqCheckers[EP_STATUS] = 1;
2581 CheckTest(boards[i+1], PosFlags(i+1), -1, -1, -1, -1, FALSE); // if we deliver check with our move, the checkers get marked
2582 // test if the victim is protected by a true protector. First make the capture.
2583 captured = boards[i+1][chaseStack[j].rt][chaseStack[j].ft];
2584 boards[i+1][chaseStack[j].rt][chaseStack[j].ft] = boards[i+1][chaseStack[j].rf][chaseStack[j].ff];
2585 boards[i+1][chaseStack[j].rf][chaseStack[j].ff] = EmptySquare;
2586 // Then test if the opponent can recapture
2587 cl.recaptures = 0; // prepare closure to pass recapture square and count moves to it
2588 cl.rt = chaseStack[j].rt;
2589 cl.ft = chaseStack[j].ft;
2590 if(appData.debugMode) {
2591 fprintf(debugFP, "test if we can recapture %c%c\n", cl.ft+AAA, cl.rt+ONE);
2593 xqCheckers[EP_STATUS] = 2; // causes GenLegal to ignore the checks we delivered with the move, in real life evaded before we captured
2594 GenLegal(boards[i+1], PosFlags(i+1), ProtectedCallback, &cl, EmptySquare); // try all moves
2595 xqCheckers[EP_STATUS] = 0; // disable quasi-legal moves again
2596 // unmake the capture
2597 boards[i+1][chaseStack[j].rf][chaseStack[j].ff] = boards[i+1][chaseStack[j].rt][chaseStack[j].ft];
2598 boards[i+1][chaseStack[j].rt][chaseStack[j].ft] = captured;
2599 // if a recapture was found, piece is protected, and we are not chasing it.
2600 if(cl.recaptures) { // attacked piece was defended by true protector, no chase
2601 chaseStack[j] = chaseStack[--chaseStackPointer]; // so delete from chaseStack
2605 // chaseStack now contains all moves that chased
2606 if(appData.debugMode) { int n;
2607 for(n=0; n<chaseStackPointer; n++)
2608 fprintf(debugFP, "%c%c%c%c ", chaseStack[n].ff+AAA, chaseStack[n].rf+ONE,
2609 chaseStack[n].ft+AAA, chaseStack[n].rt+ONE);
2610 fprintf(debugFP, ": chases\n");
2612 if(i == first) { // copy all people chased by first move of repeat cycle to preyStack
2613 for(j=0; j<chaseStackPointer; j++) {
2614 preyStack[j].rank = chaseStack[j].rt;
2615 preyStack[j].file = chaseStack[j].ft;
2617 preyStackPointer = chaseStackPointer;
2620 for(j=0; j<chaseStackPointer; j++) {
2621 for(k=0; k<preyStackPointer; k++) {
2622 // search the victim of each chase move on the preyStack (first occurrence)
2623 if(chaseStack[j].ft == preyStack[k].file && chaseStack[j].rt == preyStack[k].rank ) {
2624 if(k < tail) break; // piece was already identified as still being chased
2625 preyStack[preyStackPointer] = preyStack[tail]; // move chased piece to bottom part of preyStack
2626 preyStack[tail] = preyStack[k]; // by swapping
2627 preyStack[k] = preyStack[preyStackPointer];
2633 preyStackPointer = tail; // keep bottom part of preyStack, popping pieces unchased on move i.
2634 if(appData.debugMode) { int n;
2635 for(n=0; n<preyStackPointer; n++)
2636 fprintf(debugFP, "%c%c ", preyStack[n].file+AAA, preyStack[n].rank+ONE);
2637 fprintf(debugFP, "always chased upto ply %d\n", i);
2639 // now adjust the location of the chased pieces according to opponent move
2640 for(j=0; j<preyStackPointer; j++) {
2641 if(preyStack[j].rank == moveList[i+1][1]-ONE &&
2642 preyStack[j].file == moveList[i+1][0]-AAA+BOARD_LEFT) {
2643 preyStack[j].rank = moveList[i+1][3]-ONE;
2644 preyStack[j].file = moveList[i+1][2]-AAA+BOARD_LEFT;
2649 return preyStackPointer ? 256*(preyStack[preyStackPointer].file - BOARD_LEFT + AAA) + (preyStack[preyStackPointer].rank + ONE)
2650 : 0; // if any piece was left on preyStack, it has been perpetually chased,and we return the