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 Free Software Foundation, Inc.
10 * Enhancements Copyright 2005 Alessandro Scotti
12 * The following terms apply to Digital Equipment Corporation's copyright
14 * ------------------------------------------------------------------------
17 * Permission to use, copy, modify, and distribute this software and its
18 * documentation for any purpose and without fee is hereby granted,
19 * provided that the above copyright notice appear in all copies and that
20 * both that copyright notice and this permission notice appear in
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22 * used in advertising or publicity pertaining to distribution of the
23 * software without specific, written prior permission.
25 * DIGITAL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING
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29 * WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
30 * ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
32 * ------------------------------------------------------------------------
34 * The following terms apply to the enhanced version of XBoard
35 * distributed by the Free Software Foundation:
36 * ------------------------------------------------------------------------
38 * GNU XBoard is free software: you can redistribute it and/or modify
39 * it under the terms of the GNU General Public License as published by
40 * the Free Software Foundation, either version 3 of the License, or (at
41 * your option) any later version.
43 * GNU XBoard is distributed in the hope that it will be useful, but
44 * WITHOUT ANY WARRANTY; without even the implied warranty of
45 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
46 * General Public License for more details.
48 * You should have received a copy of the GNU General Public License
49 * along with this program. If not, see http://www.gnu.org/licenses/. *
51 *------------------------------------------------------------------------
52 ** See the file ChangeLog for a revision history. */
61 #else /* not HAVE_STRING_H */
63 #endif /* not HAVE_STRING_H */
69 int WhitePiece P((ChessSquare));
70 int BlackPiece P((ChessSquare));
71 int SameColor P((ChessSquare, ChessSquare));
72 int PosFlags(int index);
74 extern signed char initialRights[BOARD_FILES]; /* [HGM] all rights enabled, set in InitPosition */
76 char *pieceDesc[EmptySquare];
77 char *defaultDesc[EmptySquare] = {
78 "fmWfceFifmnD", "N", "B", "R", "Q",
79 "F", "A", "BN", "RN", "W", "K",
80 "mRcpR", "N0", "BW", "RF", "gQ",
81 "", "", "QN", "", "N", "",
83 "", "", "", "", "", "",
85 "", "", "", "", "", "K"
89 WhitePiece (ChessSquare piece)
91 return (int) piece >= (int) WhitePawn && (int) piece < (int) BlackPawn;
95 BlackPiece (ChessSquare piece)
97 return (int) piece >= (int) BlackPawn && (int) piece < (int) EmptySquare;
102 SameColor (ChessSquare piece1, ChessSquare piece2)
104 return ((int) piece1 >= (int) WhitePawn && /* [HGM] can be > King ! */
105 (int) piece1 < (int) BlackPawn &&
106 (int) piece2 >= (int) WhitePawn &&
107 (int) piece2 < (int) BlackPawn)
108 || ((int) piece1 >= (int) BlackPawn &&
109 (int) piece1 < (int) EmptySquare &&
110 (int) piece2 >= (int) BlackPawn &&
111 (int) piece2 < (int) EmptySquare);
114 #define SameColor(piece1, piece2) (piece1 < EmptySquare && piece2 < EmptySquare && (piece1 < BlackPawn) == (piece2 < BlackPawn) || piece1 == DarkSquare || piece2 == DarkSquare)
117 unsigned char pieceToChar[EmptySquare+1] = {
118 'P', 'N', 'B', 'R', 'Q', 'F', 'E', 'A', 'C', 'W', 'M',
119 'O', 'H', 'I', 'J', 'G', 'D', 'V', 'L', 'S', 'U', 'K',
120 'p', 'n', 'b', 'r', 'q', 'f', 'e', 'a', 'c', 'w', 'm',
121 'o', 'h', 'i', 'j', 'g', 'd', 'v', 'l', 's', 'u', 'k',
123 unsigned char pieceNickName[EmptySquare];
124 int promoPartner[EmptySquare];
127 PieceToChar (ChessSquare p)
130 if((int)p < 0 || (int)p >= (int)EmptySquare) return('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 while(*p == 'i') initial++, 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 == 2) { if(board[r][f] != initialPosition[r-2*his+3][f]) continue; } else
377 if(initial && (board[r][f] != initialPosition[r][f] ||
378 r == 0 && board[TOUCHED_W] & 1<<f ||
379 r == BOARD_HEIGHT-1 && board[TOUCHED_B] & 1<<f ) ) continue;
380 if(expo > 0 && dx == 0 && dy == 0) { // castling indicated by O + number
381 mode |= 1024; dy = 1;
383 if(expo < 0) expo = 1; // use 1 for default
385 if(!(mode & 15)) mode |= his + 4; // no mode spec, use default = mc
387 strncpy(buf, cont, 80); cont = buf; // copy next leg(s), so we can modify
388 atom = buf; while(islower(*atom)) atom++; // skip to atom
389 if(mode & 32) mode ^= 256 + 32; // in non-final legs 'p' means 'pass through'
390 if(mode & 64 + 512) {
391 mode |= 256; // and 'g' too, but converts leaper <-> slider
392 if(mode & 512) mode ^= 0x304; // and 'y' is m-like 'g'
393 *atom = upgrade[*atom-'A']; // replace atom, BRQ <-> FWK
394 atom[1] = atom[2] = '\0'; // make sure any old range is stripped off
395 if(expo == 1) atom[1] = '0'; // turn other leapers into riders
397 if(!(mode & 0x30F)) mode |= 4; // and default of this leg = m
399 if(dy == 1) skip = jump - 1, jump = 1; // on W & F atoms 'j' = skip first square
401 for(dir=0, bit=1; dir<8; dir++, bit += bit) { // loop over directions
402 int i = expo, j = skip, hop = mode, vx, vy, loop = 0;
403 if(!(bit & dirSet)) continue; // does not move in this direction
404 if(dy != 1 || mode & 1024) j = 0; //
405 vx = dx*rot[dir][0] + dy*rot[dir][1]; // rotate step vector
406 vy = dx*rot[dir][2] + dy*rot[dir][3];
407 if(tx < 0) x = f, y = r; // start square
408 else x = tx, y = ty; // from previous to-square if continuation
410 x += vx; y += vy; // step to next square
411 if(y < 0 || y >= BOARD_HEIGHT) break; // vertically off-board: always done
412 if(x < BOARD_LEFT) { if(mode & 128) x += BOARD_RGHT - BOARD_LEFT, loop++; else break; }
413 if(x >= BOARD_RGHT) { if(mode & 128) x -= BOARD_RGHT - BOARD_LEFT, loop++; else break; }
414 if(j) { j--; continue; } // skip irrespective of occupation
415 if(board[y][x] == DarkSquare) break; // black squares are supposed to be off board
416 if(!jump && board[y - vy + vy/2][x - vx + vx/2] != EmptySquare) break; // blocked
417 if(jump > 1 && board[y - vy + vy/2][x - vx + vx/2] == EmptySquare) break; // no hop
418 if(x == f && y == r && !loop) occup = 4; else // start square counts as empty (if not around cylinder!)
419 if(board[y][x] < BlackPawn) occup = 0x101; else
420 if(board[y][x] < EmptySquare) occup = 0x102; else
422 if(cont) { // non-final leg
423 if(mode&16 && his&occup) occup &= 3;// suppress hopping foe in t-mode
424 if(occup & mode) { // valid intermediate square, do continuation
425 char origAtom = *atom;
426 if(!(bit & all)) *atom = rotate[*atom - 'A']; // orth-diag interconversion to make direction valid
427 if(occup & mode & 0x104) // no side effects, merge legs to one move
428 MovesFromString(board, flags, f, r, x, y, dir, cont, cb, cl);
429 if(occup & mode & 3 && (killX < 0 || killX == x && killY == y)) { // destructive first leg
431 MovesFromString(board, flags, f, r, x, y, dir, cont, &OK, &cnt); // count possible continuations
432 if(cnt) { // and if there are
433 if(killX < 0) cb(board, flags, FirstLeg, r, f, y, x, cl); // then generate their first leg
435 MovesFromString(board, flags, f, r, x, y, dir, cont, cb, cl);
439 *atom = origAtom; // undo any interconversion
441 if(occup != 4) break; // occupied squares always terminate the leg
444 if(hop & 32+64) { if(occup != 4) { if(hop & 64 && i != 1) i = 2; hop &= 31; } continue; } // hopper
446 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)
447 cb(board, flags, mine == 1 ? WhiteCapturesEnPassant : BlackCapturesEnPassant, r, f, y, x, cl);
449 if(mode & 1024) { // castling
450 i = 2; // kludge to elongate move indefinitely
451 if(occup == 4) continue; // skip empty squares
452 if((x == BOARD_LEFT + skip || x > BOARD_LEFT + skip && vx < 0 && board[y][x-1-skip] == DarkSquare)
453 && board[y][x] == initialPosition[y][x]) { // reached initial corner piece
454 if(pc != WhiteKing && pc != BlackKing || expo == 1) { // non-royal castling (to be entered as two-leg move via 'Rook')
455 if(killX < 0) cb(board, flags, FirstLeg, r, f, y, x, cl); if(killX < f)
456 legNr <<= 1, cb(board, flags, NormalMove, r, f, y, f - expo, cl), legNr >>= 1;
458 cb(board, flags, mine == 1 ? WhiteQueenSideCastle : BlackQueenSideCastle, r, f, y, f - expo, cl);
460 if((x == BOARD_RGHT-1-skip || x < BOARD_RGHT-1-skip && vx > 0 && board[y][x+1+skip] == DarkSquare)
461 && board[y][x] == initialPosition[y][x]) {
462 if(pc != WhiteKing && pc != BlackKing || expo == 1) {
463 if(killX < 0) cb(board, flags, FirstLeg, r, f, y, x, cl); if(killX > f)
464 legNr <<= 1, cb(board, flags, NormalMove, r, f, y, f + expo, cl), legNr >>= 1;
466 cb(board, flags, mine == 1 ? WhiteKingSideCastle : BlackKingSideCastle, r, f, y, f + expo, cl);
470 if(mode & 16 && (board[y][x] == WhiteKing || board[y][x] == BlackKing)) break; // tame piece, cannot capture royal
471 if(occup & mode) cb(board, flags, y == promoRank ? promo : NormalMove, r, f, y, x, cl); // allowed, generate
472 if(occup != 4) break; // not valid transit square
475 dx = dy; dirSet = ds2; // prepare for diagonal moves of K,Q
476 } while(retry-- && ds2); // and start doing them
477 if(tx >= 0) break; // don't do other atoms in continuation legs
481 // [HGM] move generation now based on hierarchy of subroutines for rays and combinations of rays
484 SlideForward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
489 if (rt >= BOARD_HEIGHT) break;
490 if (SameColor(board[rf][ff], board[rt][ft])) break;
491 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
492 if (board[rt][ft] != EmptySquare) break;
497 SlideBackward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
503 if (SameColor(board[rf][ff], board[rt][ft])) break;
504 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
505 if (board[rt][ft] != EmptySquare) break;
510 SlideVertical (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
512 SlideForward(board, flags, rf, ff, callback, closure);
513 SlideBackward(board, flags, rf, ff, callback, closure);
517 SlideSideways (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
519 int i, s, rt = rf, ft;
520 for(s = -1; s <= 1; s+= 2) {
523 if (ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
524 if (SameColor(board[rf][ff], board[rt][ft])) break;
525 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
526 if (board[rt][ft] != EmptySquare) break;
532 SlideDiagForward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
535 for(s = -1; s <= 1; s+= 2) {
539 if (rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
540 if (SameColor(board[rf][ff], board[rt][ft])) break;
541 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
542 if (board[rt][ft] != EmptySquare) break;
548 SlideDiagBackward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
551 for(s = -1; s <= 1; s+= 2) {
555 if (rt < 0 || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
556 if (SameColor(board[rf][ff], board[rt][ft])) break;
557 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
558 if (board[rt][ft] != EmptySquare) break;
564 Rook (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
566 SlideVertical(board, flags, rf, ff, callback, closure);
567 SlideSideways(board, flags, rf, ff, callback, closure);
571 Bishop (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
573 SlideDiagForward(board, flags, rf, ff, callback, closure);
574 SlideDiagBackward(board, flags, rf, ff, callback, closure);
578 Sting (Board board, int flags, int rf, int ff, int dy, int dx, MoveCallback callback, VOIDSTAR closure)
579 { // Lion-like move of Horned Falcon and Souring Eagle
580 int ft = ff + dx, rt = rf + dy;
581 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) return;
583 if (!SameColor(board[rf][ff], board[rt][ft]))
584 callback(board, flags, board[rt][ft] != EmptySquare ? FirstLeg : NormalMove, rf, ff, rt, ft, closure);
587 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) return;
589 if (!SameColor(board[rf][ff], board[rt][ft]))
590 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
591 if (!SameColor(board[rf][ff], board[rf+dy][ff+dx]))
592 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
597 StepForward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
599 int ft = ff, rt = rf + 1;
600 if (rt >= BOARD_HEIGHT) return;
601 if (SameColor(board[rf][ff], board[rt][ft])) return;
602 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
606 StepBackward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
608 int ft = ff, rt = rf - 1;
610 if (SameColor(board[rf][ff], board[rt][ft])) return;
611 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
615 StepSideways (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
619 if (!(rt >= BOARD_HEIGHT || ft >= BOARD_RGHT) && !SameColor(board[rf][ff], board[rt][ft]))
620 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
622 if (!(rt >= BOARD_HEIGHT || ft < BOARD_LEFT) && !SameColor(board[rf][ff], board[rt][ft]))
623 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
627 StepDiagForward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
630 if (rt >= BOARD_HEIGHT) return;
632 if (!(rt >= BOARD_HEIGHT || ft >= BOARD_RGHT) && !SameColor(board[rf][ff], board[rt][ft]))
633 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
635 if (!(rt >= BOARD_HEIGHT || ft < BOARD_LEFT) && !SameColor(board[rf][ff], board[rt][ft]))
636 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
640 StepDiagBackward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
645 if (!(rt < 0 || ft >= BOARD_RGHT) && !SameColor(board[rf][ff], board[rt][ft]))
646 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
648 if (!(rt < 0 || ft < BOARD_LEFT) && !SameColor(board[rf][ff], board[rt][ft]))
649 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
653 StepVertical (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
655 StepForward(board, flags, rf, ff, callback, closure);
656 StepBackward(board, flags, rf, ff, callback, closure);
660 Ferz (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
662 StepDiagForward(board, flags, rf, ff, callback, closure);
663 StepDiagBackward(board, flags, rf, ff, callback, closure);
667 Wazir (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
669 StepVertical(board, flags, rf, ff, callback, closure);
670 StepSideways(board, flags, rf, ff, callback, closure);
674 Knight (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
677 for (i = -1; i <= 1; i += 2)
678 for (j = -1; j <= 1; j += 2)
679 for (s = 1; s <= 2; s++) {
682 if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
683 && ( gameInfo.variant != VariantXiangqi || board[rf+i*(s-1)][ff+j*(2-s)] == EmptySquare)
684 && !SameColor(board[rf][ff], board[rt][ft]))
685 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
689 /* Call callback once for each pseudo-legal move in the given
690 position, except castling moves. A move is pseudo-legal if it is
691 legal, or if it would be legal except that it leaves the king in
692 check. In the arguments, epfile is EP_NONE if the previous move
693 was not a double pawn push, or the file 0..7 if it was, or
694 EP_UNKNOWN if we don't know and want to allow all e.p. captures.
695 Promotion moves generated are to Queen only.
698 GenPseudoLegal (Board board, int flags, MoveCallback callback, VOIDSTAR closure, ChessSquare filter)
699 // speed: only do moves with this piece type
702 int i, j, d, s, fs, rs, rt, ft, m;
703 int epfile = (signed char)board[EP_STATUS]; // [HGM] gamestate: extract ep status from board
704 int promoRank = gameInfo.variant == VariantMakruk || gameInfo.variant == VariantGrand || gameInfo.variant == VariantChuChess ? 3 : 1;
706 for (rf = 0; rf < BOARD_HEIGHT; rf++)
707 for (ff = BOARD_LEFT; ff < BOARD_RGHT; ff++) {
710 if(board[rf][ff] == EmptySquare) continue;
711 if ((flags & F_WHITE_ON_MOVE) != (board[rf][ff] < BlackPawn)) continue; // [HGM] speed: wrong color
712 m = 0; piece = board[rf][ff];
713 if(PieceToChar(piece) == '~')
714 piece = (ChessSquare) ( DEMOTED(piece) );
715 if(filter != EmptySquare && piece != filter) continue;
716 if(pieceDefs && pieceDesc[piece]) { // [HGM] gen: use engine-defined moves
717 MovesFromString(board, flags, ff, rf, -1, -1, 0, pieceDesc[piece], callback, closure);
720 if(IS_SHOGI(gameInfo.variant))
721 piece = (ChessSquare) ( SHOGI piece );
723 switch ((int)piece) {
724 /* case EmptySquare: [HGM] this is nonsense, and conflicts with Shogi cases */
726 /* can't happen ([HGM] except for faries...) */
730 if(gameInfo.variant == VariantXiangqi) {
731 /* [HGM] capture and move straight ahead in Xiangqi */
732 if (rf < BOARD_HEIGHT-1 &&
733 !SameColor(board[rf][ff], board[rf + 1][ff]) ) {
734 callback(board, flags, NormalMove,
735 rf, ff, rf + 1, ff, closure);
737 /* and move sideways when across the river */
738 for (s = -1; s <= 1; s += 2) {
739 if (rf >= BOARD_HEIGHT>>1 &&
740 ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
741 !WhitePiece(board[rf][ff+s]) ) {
742 callback(board, flags, NormalMove,
743 rf, ff, rf, ff+s, closure);
748 if (rf < BOARD_HEIGHT-1 && board[rf + 1][ff] == EmptySquare) {
749 callback(board, flags,
750 rf >= BOARD_HEIGHT-1-promoRank ? WhitePromotion : NormalMove,
751 rf, ff, rf + 1, ff, closure);
753 if (rf <= (BOARD_HEIGHT>>1)-3 && board[rf+1][ff] == EmptySquare && // [HGM] grand: also on 3rd rank on 10-board
754 gameInfo.variant != VariantShatranj && /* [HGM] */
755 gameInfo.variant != VariantCourier && /* [HGM] */
756 board[rf+2][ff] == EmptySquare ) {
757 callback(board, flags, NormalMove,
758 rf, ff, rf+2, ff, closure);
760 for (s = -1; s <= 1; s += 2) {
761 if (rf < BOARD_HEIGHT-1 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
762 ((flags & F_KRIEGSPIEL_CAPTURE) ||
763 BlackPiece(board[rf + 1][ff + s]))) {
764 callback(board, flags,
765 rf >= BOARD_HEIGHT-1-promoRank ? WhitePromotion : NormalMove,
766 rf, ff, rf + 1, ff + s, closure);
768 if (rf >= BOARD_HEIGHT+1>>1) {// [HGM] grand: 4th & 5th rank on 10-board
769 if (ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
770 (epfile == ff + s || epfile == EP_UNKNOWN) && rf < BOARD_HEIGHT-3 &&
771 board[rf][ff + s] == BlackPawn &&
772 board[rf+1][ff + s] == EmptySquare) {
773 callback(board, flags, WhiteCapturesEnPassant,
774 rf, ff, rf+1, ff + s, closure);
781 if(gameInfo.variant == VariantXiangqi) {
782 /* [HGM] capture straight ahead in Xiangqi */
783 if (rf > 0 && !SameColor(board[rf][ff], board[rf - 1][ff]) ) {
784 callback(board, flags, NormalMove,
785 rf, ff, rf - 1, ff, closure);
787 /* and move sideways when across the river */
788 for (s = -1; s <= 1; s += 2) {
789 if (rf < BOARD_HEIGHT>>1 &&
790 ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
791 !BlackPiece(board[rf][ff+s]) ) {
792 callback(board, flags, NormalMove,
793 rf, ff, rf, ff+s, closure);
798 if (rf > 0 && board[rf - 1][ff] == EmptySquare) {
799 callback(board, flags,
800 rf <= promoRank ? BlackPromotion : NormalMove,
801 rf, ff, rf - 1, ff, closure);
803 if (rf >= (BOARD_HEIGHT+1>>1)+2 && board[rf-1][ff] == EmptySquare && // [HGM] grand
804 gameInfo.variant != VariantShatranj && /* [HGM] */
805 gameInfo.variant != VariantCourier && /* [HGM] */
806 board[rf-2][ff] == EmptySquare) {
807 callback(board, flags, NormalMove,
808 rf, ff, rf-2, ff, closure);
810 for (s = -1; s <= 1; s += 2) {
811 if (rf > 0 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
812 ((flags & F_KRIEGSPIEL_CAPTURE) ||
813 WhitePiece(board[rf - 1][ff + s]))) {
814 callback(board, flags,
815 rf <= promoRank ? BlackPromotion : NormalMove,
816 rf, ff, rf - 1, ff + s, closure);
818 if (rf < BOARD_HEIGHT>>1) {
819 if (ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
820 (epfile == ff + s || epfile == EP_UNKNOWN) && rf > 2 &&
821 board[rf][ff + s] == WhitePawn &&
822 board[rf-1][ff + s] == EmptySquare) {
823 callback(board, flags, BlackCapturesEnPassant,
824 rf, ff, rf-1, ff + s, closure);
834 for (i = -1; i <= 1; i += 2)
835 for (j = -1; j <= 1; j += 2)
836 for (s = 1; s <= 2; s++) {
839 if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
840 && ( gameInfo.variant != VariantXiangqi || board[rf+i*(s-1)][ff+j*(2-s)] == EmptySquare)
841 && !SameColor(board[rf][ff], board[rt][ft]))
842 callback(board, flags, NormalMove,
843 rf, ff, rt, ft, closure);
847 case SHOGI WhiteKnight:
848 for (s = -1; s <= 1; s += 2) {
849 if (rf < BOARD_HEIGHT-2 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
850 !SameColor(board[rf][ff], board[rf + 2][ff + s])) {
851 callback(board, flags, NormalMove,
852 rf, ff, rf + 2, ff + s, closure);
857 case SHOGI BlackKnight:
858 for (s = -1; s <= 1; s += 2) {
859 if (rf > 1 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
860 !SameColor(board[rf][ff], board[rf - 2][ff + s])) {
861 callback(board, flags, NormalMove,
862 rf, ff, rf - 2, ff + s, closure);
869 for (d = 0; d <= 1; d++)
870 for (s = -1; s <= 1; s += 2) {
873 rt = rf + (i * s) * d;
874 ft = ff + (i * s) * (1 - d);
875 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
876 if (m == 0 && board[rt][ft] == EmptySquare)
877 callback(board, flags, NormalMove,
878 rf, ff, rt, ft, closure);
879 if (m == 1 && board[rt][ft] != EmptySquare &&
880 !SameColor(board[rf][ff], board[rt][ft]) )
881 callback(board, flags, NormalMove,
882 rf, ff, rt, ft, closure);
883 if (board[rt][ft] != EmptySquare && m++) break;
888 /* Gold General (and all its promoted versions) . First do the */
889 /* diagonal forward steps, then proceed as normal Wazir */
890 case SHOGI (PROMO WhitePawn):
891 if(gameInfo.variant == VariantShogi) goto WhiteGold;
892 case SHOGI (PROMO BlackPawn):
893 if(gameInfo.variant == VariantShogi) goto BlackGold;
894 SlideVertical(board, flags, rf, ff, callback, closure);
897 case SHOGI (PROMO WhiteKnight):
898 if(gameInfo.variant == VariantShogi) goto WhiteGold;
899 case SHOGI BlackDrunk:
900 case SHOGI BlackAlfil:
901 Ferz(board, flags, rf, ff, callback, closure);
902 StepSideways(board, flags, rf, ff, callback, closure);
903 StepBackward(board, flags, rf, ff, callback, closure);
906 case SHOGI (PROMO BlackKnight):
907 if(gameInfo.variant == VariantShogi) goto BlackGold;
908 case SHOGI WhiteDrunk:
909 case SHOGI WhiteAlfil:
910 Ferz(board, flags, rf, ff, callback, closure);
911 StepSideways(board, flags, rf, ff, callback, closure);
912 StepForward(board, flags, rf, ff, callback, closure);
916 case SHOGI WhiteStag:
917 case SHOGI BlackStag:
918 if(gameInfo.variant == VariantShogi) goto BlackGold;
919 SlideVertical(board, flags, rf, ff, callback, closure);
920 Ferz(board, flags, rf, ff, callback, closure);
921 StepSideways(board, flags, rf, ff, callback, closure);
924 case SHOGI (PROMO WhiteQueen):
925 case SHOGI WhiteTokin:
926 case SHOGI WhiteWazir:
928 StepDiagForward(board, flags, rf, ff, callback, closure);
929 Wazir(board, flags, rf, ff, callback, closure);
932 case SHOGI (PROMO BlackQueen):
933 case SHOGI BlackTokin:
934 case SHOGI BlackWazir:
936 StepDiagBackward(board, flags, rf, ff, callback, closure);
937 Wazir(board, flags, rf, ff, callback, closure);
942 Wazir(board, flags, rf, ff, callback, closure);
945 case SHOGI WhiteMarshall:
946 case SHOGI BlackMarshall:
947 Ferz(board, flags, rf, ff, callback, closure);
948 for (d = 0; d <= 1; d++)
949 for (s = -2; s <= 2; s += 4) {
951 ft = ff + s * (1 - d);
952 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) continue;
953 if (!SameColor(board[rf][ff], board[rt][ft]) )
954 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
958 case SHOGI WhiteAngel:
959 case SHOGI BlackAngel:
960 Wazir(board, flags, rf, ff, callback, closure);
964 /* [HGM] support Shatranj pieces */
965 for (rs = -1; rs <= 1; rs += 2)
966 for (fs = -1; fs <= 1; fs += 2) {
969 if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
970 && ( gameInfo.variant != VariantXiangqi ||
971 board[rf+rs][ff+fs] == EmptySquare && (2*rf < BOARD_HEIGHT) == (2*rt < BOARD_HEIGHT) )
973 && !SameColor(board[rf][ff], board[rt][ft]))
974 callback(board, flags, NormalMove,
975 rf, ff, rt, ft, closure);
976 if(gameInfo.variant == VariantShatranj || gameInfo.variant == VariantCourier ||
977 gameInfo.variant == VariantChu || gameInfo.variant == VariantXiangqi) continue; // classical Alfil
978 rt = rf + rs; // in unknown variant we assume Modern Elephant, which can also do one step
980 if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
981 && !SameColor(board[rf][ff], board[rt][ft]))
982 callback(board, flags, NormalMove,
983 rf, ff, rt, ft, closure);
985 if(gameInfo.variant == VariantSpartan)
986 for(fs = -1; fs <= 1; fs += 2) {
988 if (!(ft < BOARD_LEFT || ft >= BOARD_RGHT) && board[rf][ft] == EmptySquare)
989 callback(board, flags, NormalMove, rf, ff, rf, ft, closure);
993 /* Make Dragon-Horse also do Dababba moves outside Shogi, for better disambiguation in variant Fairy */
996 if(gameInfo.variant == VariantChuChess) goto DragonHorse;
997 for (d = 0; d <= 1; d++) // Dababba moves that Rook cannot do
998 for (s = -2; s <= 2; s += 4) {
1000 ft = ff + s * (1 - d);
1001 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) continue;
1002 if (SameColor(board[rf][ff], board[rt][ft])) continue;
1003 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
1006 /* Shogi Dragon Horse has to continue with Wazir after Bishop */
1007 case SHOGI WhiteCardinal:
1008 case SHOGI BlackCardinal:
1009 case SHOGI WhitePCardinal:
1010 case SHOGI BlackPCardinal:
1012 Bishop(board, flags, rf, ff, callback, closure);
1013 Wazir(board, flags, rf, ff, callback, closure);
1016 /* Capablanca Archbishop continues as Knight */
1019 Knight(board, flags, rf, ff, callback, closure);
1021 /* Shogi Bishops are ordinary Bishops */
1022 case SHOGI WhiteBishop:
1023 case SHOGI BlackBishop:
1024 case SHOGI WhitePBishop:
1025 case SHOGI BlackPBishop:
1028 Bishop(board, flags, rf, ff, callback, closure);
1031 /* Shogi Lance is unlike anything, and asymmetric at that */
1032 case SHOGI WhiteQueen:
1033 if(gameInfo.variant == VariantChu) goto doQueen;
1037 if (rt >= BOARD_HEIGHT) break;
1038 if (SameColor(board[rf][ff], board[rt][ft])) break;
1039 callback(board, flags, NormalMove,
1040 rf, ff, rt, ft, closure);
1041 if (board[rt][ft] != EmptySquare) break;
1045 case SHOGI BlackQueen:
1046 if(gameInfo.variant == VariantChu) goto doQueen;
1051 if (SameColor(board[rf][ff], board[rt][ft])) break;
1052 callback(board, flags, NormalMove,
1053 rf, ff, rt, ft, closure);
1054 if (board[rt][ft] != EmptySquare) break;
1058 /* Make Dragon-King Dababba & Rook-like outside Shogi, for better disambiguation in variant Fairy */
1061 if(gameInfo.variant == VariantChuChess) goto DragonKing;
1062 for (d = 0; d <= 1; d++) // Dababba moves that Rook cannot do
1063 for (s = -2; s <= 2; s += 4) {
1065 ft = ff + s * (1 - d);
1066 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) continue;
1067 if (board[rf+rt>>1][ff+ft>>1] == EmptySquare && gameInfo.variant != VariantSpartan) continue;
1068 if (SameColor(board[rf][ff], board[rt][ft])) continue;
1069 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
1071 if(gameInfo.variant == VariantSpartan) // in Spartan Chess restrict range to modern Dababba
1072 Wazir(board, flags, rf, ff, callback, closure);
1074 Rook(board, flags, rf, ff, callback, closure);
1077 /* Shogi Dragon King has to continue as Ferz after Rook moves */
1078 case SHOGI WhiteDragon:
1079 case SHOGI BlackDragon:
1080 case SHOGI WhitePDragon:
1081 case SHOGI BlackPDragon:
1083 Rook(board, flags, rf, ff, callback, closure);
1084 Ferz(board, flags, rf, ff, callback, closure);
1088 /* Capablanca Chancellor sets flag to continue as Knight */
1091 Rook(board, flags, rf, ff, callback, closure);
1092 if(gameInfo.variant == VariantSpartan) // in Spartan Chess Chancellor is used for Dragon King.
1093 Ferz(board, flags, rf, ff, callback, closure);
1095 Knight(board, flags, rf, ff, callback, closure);
1098 /* Shogi Rooks are ordinary Rooks */
1099 case SHOGI WhiteRook:
1100 case SHOGI BlackRook:
1101 case SHOGI WhitePRook:
1102 case SHOGI BlackPRook:
1105 Rook(board, flags, rf, ff, callback, closure);
1110 case SHOGI WhiteMother:
1111 case SHOGI BlackMother:
1113 Rook(board, flags, rf, ff, callback, closure);
1114 Bishop(board, flags, rf, ff, callback, closure);
1117 case SHOGI WhitePawn:
1118 StepForward(board, flags, rf, ff, callback, closure);
1121 case SHOGI BlackPawn:
1122 StepBackward(board, flags, rf, ff, callback, closure);
1126 if(gameInfo.variant != VariantMakruk && gameInfo.variant != VariantASEAN) goto commoner;
1127 case SHOGI WhiteFerz:
1128 Ferz(board, flags, rf, ff, callback, closure);
1129 StepForward(board, flags, rf, ff, callback, closure);
1133 if(gameInfo.variant != VariantMakruk && gameInfo.variant != VariantASEAN) goto commoner;
1134 case SHOGI BlackFerz:
1135 StepBackward(board, flags, rf, ff, callback, closure);
1139 /* [HGM] support Shatranj pieces */
1140 Ferz(board, flags, rf, ff, callback, closure);
1145 Knight(board, flags, rf, ff, callback, closure); // [HGM] superchess: use for Centaur
1148 case SHOGI WhiteMonarch:
1149 case SHOGI BlackMonarch:
1150 case SHOGI WhiteKing:
1151 case SHOGI BlackKing:
1154 Ferz(board, flags, rf, ff, callback, closure);
1155 Wazir(board, flags, rf, ff, callback, closure);
1158 case WhiteNightrider:
1159 case BlackNightrider:
1160 for (i = -1; i <= 1; i += 2)
1161 for (j = -1; j <= 1; j += 2)
1162 for (s = 1; s <= 2; s++) { int k;
1165 ft = ff + k*j*(3-s);
1166 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
1167 if (SameColor(board[rf][ff], board[rt][ft])) break;
1168 callback(board, flags, NormalMove,
1169 rf, ff, rt, ft, closure);
1170 if (board[rt][ft] != EmptySquare) break;
1176 Bishop(board, flags, rf, ff, callback, closure);
1177 Rook(board, flags, rf, ff, callback, closure);
1178 Knight(board, flags, rf, ff, callback, closure);
1181 // Use Lance as Berolina / Spartan Pawn.
1183 if(gameInfo.variant == VariantSuper) goto Amazon;
1184 if (rf < BOARD_HEIGHT-1 && BlackPiece(board[rf + 1][ff]))
1185 callback(board, flags,
1186 rf >= BOARD_HEIGHT-1-promoRank ? WhitePromotion : NormalMove,
1187 rf, ff, rf + 1, ff, closure);
1188 for (s = -1; s <= 1; s += 2) {
1189 if (rf < BOARD_HEIGHT-1 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT && board[rf + 1][ff + s] == EmptySquare)
1190 callback(board, flags,
1191 rf >= BOARD_HEIGHT-1-promoRank ? WhitePromotion : NormalMove,
1192 rf, ff, rf + 1, ff + s, closure);
1193 if (rf == 1 && ff + 2*s >= BOARD_LEFT && ff + 2*s < BOARD_RGHT && board[3][ff + 2*s] == EmptySquare )
1194 callback(board, flags, NormalMove, rf, ff, 3, ff + 2*s, closure);
1199 if(gameInfo.variant == VariantSuper) goto Amazon;
1200 if (rf > 0 && WhitePiece(board[rf - 1][ff]))
1201 callback(board, flags,
1202 rf <= promoRank ? BlackPromotion : NormalMove,
1203 rf, ff, rf - 1, ff, closure);
1204 for (s = -1; s <= 1; s += 2) {
1205 if (rf > 0 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT && board[rf - 1][ff + s] == EmptySquare)
1206 callback(board, flags,
1207 rf <= promoRank ? BlackPromotion : NormalMove,
1208 rf, ff, rf - 1, ff + s, closure);
1209 if (rf == BOARD_HEIGHT-2 && ff + 2*s >= BOARD_LEFT && ff + 2*s < BOARD_RGHT && board[rf-2][ff + 2*s] == EmptySquare )
1210 callback(board, flags, NormalMove, rf, ff, rf-2, ff + 2*s, closure);
1214 case SHOGI WhiteNothing:
1215 case SHOGI BlackNothing:
1216 case SHOGI WhiteLion:
1217 case SHOGI BlackLion:
1220 for(rt = rf - 2; rt <= rf + 2; rt++) for(ft = ff - 2; ft <= ff + 2; ft++) {
1221 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) continue;
1222 if (!(ff == ft && rf == rt) && SameColor(board[rf][ff], board[rt][ft])) continue;
1223 i = (killX >= 0 && (rt-killY)*(rt-killY) + (killX-ft)*(killX-ft) < 3); legNr += 2*i;
1224 callback(board, flags, (rt-rf)*(rt-rf) + (ff-ft)*(ff-ft) < 3 && board[rt][ft] != EmptySquare ? FirstLeg : NormalMove,
1225 rf, ff, rt, ft, closure);
1230 case SHOGI WhiteFalcon:
1231 case SHOGI BlackFalcon:
1232 case SHOGI WhitePDagger:
1233 case SHOGI BlackPDagger:
1234 SlideSideways(board, flags, rf, ff, callback, closure);
1235 StepVertical(board, flags, rf, ff, callback, closure);
1238 case SHOGI WhiteCobra:
1239 case SHOGI BlackCobra:
1240 StepVertical(board, flags, rf, ff, callback, closure);
1243 case SHOGI (PROMO WhiteFerz):
1244 if(gameInfo.variant == VariantShogi) goto WhiteGold;
1245 case SHOGI (PROMO BlackFerz):
1246 if(gameInfo.variant == VariantShogi) goto BlackGold;
1247 case SHOGI WhitePSword:
1248 case SHOGI BlackPSword:
1249 SlideVertical(board, flags, rf, ff, callback, closure);
1250 StepSideways(board, flags, rf, ff, callback, closure);
1253 case SHOGI WhiteUnicorn:
1254 case SHOGI BlackUnicorn:
1255 Ferz(board, flags, rf, ff, callback, closure);
1256 StepVertical(board, flags, rf, ff, callback, closure);
1259 case SHOGI WhiteMan:
1260 StepDiagForward(board, flags, rf, ff, callback, closure);
1261 StepVertical(board, flags, rf, ff, callback, closure);
1264 case SHOGI BlackMan:
1265 StepDiagBackward(board, flags, rf, ff, callback, closure);
1266 StepVertical(board, flags, rf, ff, callback, closure);
1269 case SHOGI WhiteHCrown:
1270 case SHOGI BlackHCrown:
1271 Bishop(board, flags, rf, ff, callback, closure);
1272 SlideSideways(board, flags, rf, ff, callback, closure);
1275 case SHOGI WhiteCrown:
1276 case SHOGI BlackCrown:
1277 Bishop(board, flags, rf, ff, callback, closure);
1278 SlideVertical(board, flags, rf, ff, callback, closure);
1281 case SHOGI WhiteHorned:
1282 Sting(board, flags, rf, ff, 1, 0, callback, closure);
1283 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1284 if(killX >= 0) break;
1285 Bishop(board, flags, rf, ff, callback, closure);
1286 SlideSideways(board, flags, rf, ff, callback, closure);
1287 SlideBackward(board, flags, rf, ff, callback, closure);
1290 case SHOGI BlackHorned:
1291 Sting(board, flags, rf, ff, -1, 0, callback, closure);
1292 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1293 if(killX >= 0) break;
1294 Bishop(board, flags, rf, ff, callback, closure);
1295 SlideSideways(board, flags, rf, ff, callback, closure);
1296 SlideForward(board, flags, rf, ff, callback, closure);
1299 case SHOGI WhiteEagle:
1300 Sting(board, flags, rf, ff, 1, 1, callback, closure);
1301 Sting(board, flags, rf, ff, 1, -1, callback, closure);
1302 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1303 if(killX >= 0) break;
1304 Rook(board, flags, rf, ff, callback, closure);
1305 SlideDiagBackward(board, flags, rf, ff, callback, closure);
1308 case SHOGI BlackEagle:
1309 Sting(board, flags, rf, ff, -1, 1, callback, closure);
1310 Sting(board, flags, rf, ff, -1, -1, callback, closure);
1311 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1312 if(killX >= 0) break;
1313 Rook(board, flags, rf, ff, callback, closure);
1314 SlideDiagForward(board, flags, rf, ff, callback, closure);
1317 case SHOGI WhiteDolphin:
1318 case SHOGI BlackHorse:
1319 SlideDiagBackward(board, flags, rf, ff, callback, closure);
1320 SlideVertical(board, flags, rf, ff, callback, closure);
1323 case SHOGI BlackDolphin:
1324 case SHOGI WhiteHorse:
1325 SlideDiagForward(board, flags, rf, ff, callback, closure);
1326 SlideVertical(board, flags, rf, ff, callback, closure);
1329 case SHOGI WhiteLance:
1330 SlideForward(board, flags, rf, ff, callback, closure);
1333 case SHOGI BlackLance:
1334 SlideBackward(board, flags, rf, ff, callback, closure);
1337 case WhiteFalcon: // [HGM] wild: for wildcards, self-capture symbolizes move to anywhere
1341 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1354 int rFilter, fFilter; // [HGM] speed: sorry, but I get a bit tired of this closure madness
1355 Board xqCheckers, nullBoard;
1357 extern void GenLegalCallback P((Board board, int flags, ChessMove kind,
1358 int rf, int ff, int rt, int ft,
1362 GenLegalCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1364 register GenLegalClosure *cl = (GenLegalClosure *) closure;
1366 if(rFilter >= 0 && rFilter != rt || fFilter >= 0 && fFilter != ft) return; // [HGM] speed: ignore moves with wrong to-square
1368 if (board[EP_STATUS] == EP_IRON_LION && (board[rt][ft] == WhiteLion || board[rt][ft] == BlackLion)) return; //[HGM] lion
1370 if (!(flags & F_IGNORE_CHECK) ) {
1371 int check, promo = (gameInfo.variant == VariantSpartan && kind == BlackPromotion);
1374 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++)
1375 kings += (board[r][f] == BlackKing);
1379 board[rf][ff] = BlackKing; // [HGM] spartan: promote to King before check-test
1381 check = CheckTest(board, flags, rf, ff, rt, ft,
1382 kind == WhiteCapturesEnPassant ||
1383 kind == BlackCapturesEnPassant);
1384 if(promo) board[rf][ff] = BlackLance;
1387 if (flags & F_ATOMIC_CAPTURE) {
1388 if (board[rt][ft] != EmptySquare ||
1389 kind == WhiteCapturesEnPassant || kind == BlackCapturesEnPassant) {
1391 ChessSquare king = (flags & F_WHITE_ON_MOVE) ? WhiteKing : BlackKing;
1392 if (board[rf][ff] == king) return;
1393 for (r = rt-1; r <= rt+1; r++) {
1394 for (f = ft-1; f <= ft+1; f++) {
1395 if (r >= 0 && r < BOARD_HEIGHT && f >= BOARD_LEFT && f < BOARD_RGHT &&
1396 board[r][f] == king) return;
1401 cl->cb(board, flags, kind, rf, ff, rt, ft, cl->cl);
1408 int captures; // [HGM] losers
1409 } LegalityTestClosure;
1412 /* Like GenPseudoLegal, but (1) include castling moves, (2) unless
1413 F_IGNORE_CHECK is set in the flags, omit moves that would leave the
1414 king in check, and (3) if F_ATOMIC_CAPTURE is set in the flags, omit
1415 moves that would destroy your own king. The CASTLE_OK flags are
1416 true if castling is not yet ruled out by a move of the king or
1417 rook. Return TRUE if the player on move is currently in check and
1418 F_IGNORE_CHECK is not set. [HGM] add castlingRights parameter */
1420 GenLegal (Board board, int flags, MoveCallback callback, VOIDSTAR closure, ChessSquare filter)
1423 int ff, ft, k, left, right, swap;
1424 int ignoreCheck = (flags & F_IGNORE_CHECK) != 0;
1425 ChessSquare wKing = WhiteKing, bKing = BlackKing, *castlingRights = board[CASTLING];
1426 int inCheck = !ignoreCheck && CheckTest(board, flags, -1, -1, -1, -1, FALSE); // kludge alert: this would mark pre-existing checkers if status==1
1431 xqCheckers[EP_STATUS] *= 2; // quasi: if previous CheckTest has been marking, we now set flag for suspending same checkers
1432 if(filter == EmptySquare) rFilter = fFilter = -1; // [HGM] speed: do not filter on square if we do not filter on piece
1433 GenPseudoLegal(board, flags, GenLegalCallback, (VOIDSTAR) &cl, filter);
1435 if (inCheck) return TRUE;
1437 /* Generate castling moves */
1438 if(gameInfo.variant == VariantKnightmate) { /* [HGM] Knightmate */
1439 wKing = WhiteUnicorn; bKing = BlackUnicorn;
1442 p = (flags & F_WHITE_ON_MOVE ? pieceDesc[wKing] : pieceDesc[bKing]);
1443 if(p && strchr(p, 'O')) return FALSE; // [HGM] gen: castlings were already generated from string
1445 for (ff = BOARD_WIDTH>>1; ff >= (BOARD_WIDTH-1)>>1; ff-- /*ics wild 1*/) {
1446 if ((flags & F_WHITE_ON_MOVE) &&
1447 (flags & F_WHITE_KCASTLE_OK) &&
1448 board[0][ff] == wKing &&
1449 board[0][ff + 1] == EmptySquare &&
1450 board[0][ff + 2] == EmptySquare &&
1451 board[0][BOARD_RGHT-3] == EmptySquare &&
1452 board[0][BOARD_RGHT-2] == EmptySquare &&
1453 board[0][BOARD_RGHT-1] == WhiteRook &&
1454 castlingRights[0] != NoRights && /* [HGM] check rights */
1455 ( castlingRights[2] == ff || castlingRights[6] == ff ) &&
1457 (!CheckTest(board, flags, 0, ff, 0, ff + 1, FALSE) &&
1458 !CheckTest(board, flags, 0, ff, 0, BOARD_RGHT-3, FALSE) &&
1459 (gameInfo.variant != VariantJanus || !CheckTest(board, flags, 0, ff, 0, BOARD_RGHT-2, FALSE)) &&
1460 !CheckTest(board, flags, 0, ff, 0, ff + 2, FALSE)))) {
1462 callback(board, flags,
1463 ff==BOARD_WIDTH>>1 ? WhiteKingSideCastle : WhiteKingSideCastleWild,
1464 0, ff, 0, ff + ((gameInfo.boardWidth+2)>>2) + (gameInfo.variant == VariantJanus), closure);
1466 if ((flags & F_WHITE_ON_MOVE) &&
1467 (flags & F_WHITE_QCASTLE_OK) &&
1468 board[0][ff] == wKing &&
1469 board[0][ff - 1] == EmptySquare &&
1470 board[0][ff - 2] == EmptySquare &&
1471 board[0][BOARD_LEFT+2] == EmptySquare &&
1472 board[0][BOARD_LEFT+1] == EmptySquare &&
1473 board[0][BOARD_LEFT+0] == WhiteRook &&
1474 castlingRights[1] != NoRights && /* [HGM] check rights */
1475 ( castlingRights[2] == ff || castlingRights[6] == ff ) &&
1477 (!CheckTest(board, flags, 0, ff, 0, ff - 1, FALSE) &&
1478 !CheckTest(board, flags, 0, ff, 0, BOARD_LEFT+3, FALSE) &&
1479 !CheckTest(board, flags, 0, ff, 0, ff - 2, FALSE)))) {
1481 callback(board, flags,
1482 ff==BOARD_WIDTH>>1 ? WhiteQueenSideCastle : WhiteQueenSideCastleWild,
1483 0, ff, 0, ff - ((gameInfo.boardWidth+2)>>2), closure);
1485 if (!(flags & F_WHITE_ON_MOVE) &&
1486 (flags & F_BLACK_KCASTLE_OK) &&
1487 board[BOARD_HEIGHT-1][ff] == bKing &&
1488 board[BOARD_HEIGHT-1][ff + 1] == EmptySquare &&
1489 board[BOARD_HEIGHT-1][ff + 2] == EmptySquare &&
1490 board[BOARD_HEIGHT-1][BOARD_RGHT-3] == EmptySquare &&
1491 board[BOARD_HEIGHT-1][BOARD_RGHT-2] == EmptySquare &&
1492 board[BOARD_HEIGHT-1][BOARD_RGHT-1] == BlackRook &&
1493 castlingRights[3] != NoRights && /* [HGM] check rights */
1494 ( castlingRights[5] == ff || castlingRights[7] == ff ) &&
1496 (!CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff + 1, FALSE) &&
1497 !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, BOARD_RGHT-3, FALSE) &&
1498 (gameInfo.variant != VariantJanus || !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, BOARD_RGHT-2, FALSE)) &&
1499 !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff + 2, FALSE)))) {
1501 callback(board, flags,
1502 ff==BOARD_WIDTH>>1 ? BlackKingSideCastle : BlackKingSideCastleWild,
1503 BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff + ((gameInfo.boardWidth+2)>>2) + (gameInfo.variant == VariantJanus), closure);
1505 if (!(flags & F_WHITE_ON_MOVE) &&
1506 (flags & F_BLACK_QCASTLE_OK) &&
1507 board[BOARD_HEIGHT-1][ff] == bKing &&
1508 board[BOARD_HEIGHT-1][ff - 1] == EmptySquare &&
1509 board[BOARD_HEIGHT-1][ff - 2] == EmptySquare &&
1510 board[BOARD_HEIGHT-1][BOARD_LEFT+2] == EmptySquare &&
1511 board[BOARD_HEIGHT-1][BOARD_LEFT+1] == EmptySquare &&
1512 board[BOARD_HEIGHT-1][BOARD_LEFT+0] == BlackRook &&
1513 castlingRights[4] != NoRights && /* [HGM] check rights */
1514 ( castlingRights[5] == ff || castlingRights[7] == ff ) &&
1516 (!CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff - 1, FALSE) &&
1517 !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, BOARD_LEFT+3, FALSE) &&
1518 !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff - 2, FALSE)))) {
1520 callback(board, flags,
1521 ff==BOARD_WIDTH>>1 ? BlackQueenSideCastle : BlackQueenSideCastleWild,
1522 BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff - ((gameInfo.boardWidth+2)>>2), closure);
1526 if((swap = gameInfo.variant == VariantSChess) || flags & F_FRC_TYPE_CASTLING) {
1528 /* generate all potential FRC castling moves (KxR), ignoring flags */
1529 /* [HGM] test if the Rooks we find have castling rights */
1530 /* In S-Chess we generate RxK for allowed castlings, for gating at Rook square */
1533 if ((flags & F_WHITE_ON_MOVE) != 0) {
1534 ff = castlingRights[2]; /* King file if we have any rights */
1535 if(ff != NoRights && board[0][ff] == WhiteKing) {
1536 if (appData.debugMode) {
1537 fprintf(debugFP, "FRC castling, %d %d %d %d %d %d\n",
1538 castlingRights[0],castlingRights[1],ff,castlingRights[3],castlingRights[4],castlingRights[5]);
1540 ft = castlingRights[0]; /* Rook file if we have H-side rights */
1542 right = BOARD_RGHT-2;
1543 if(ff == BOARD_RGHT-2) left = right = ff-1; /* special case */
1544 for(k=left; k<=right && ft != NoRights; k++) /* first test if blocked */
1545 if(k != ft && board[0][k] != EmptySquare) ft = NoRights;
1546 for(k=left; k<right && ft != NoRights; k++) /* then if not checked */
1547 if(!ignoreCheck && CheckTest(board, flags, 0, ff, 0, k, FALSE)) ft = NoRights;
1548 if(ft != NoRights && board[0][ft] == WhiteRook) {
1549 if(flags & F_FRC_TYPE_CASTLING) callback(board, flags, WhiteHSideCastleFR, 0, ff, 0, ft, closure);
1550 if(swap) callback(board, flags, WhiteHSideCastleFR, 0, ft, 0, ff, closure);
1553 ft = castlingRights[1]; /* Rook file if we have A-side rights */
1554 left = BOARD_LEFT+2;
1556 if(ff <= BOARD_LEFT+2) { left = ff+1; right = BOARD_LEFT+3; }
1557 for(k=left; k<=right && ft != NoRights; k++) /* first test if blocked */
1558 if(k != ft && board[0][k] != EmptySquare) ft = NoRights;
1559 if(ft == 0 && ff != 1 && board[0][1] != EmptySquare) ft = NoRights; /* Rook can be blocked on b1 */
1560 if(ff > BOARD_LEFT+2)
1561 for(k=left+1; k<=right && ft != NoRights; k++) /* then if not checked */
1562 if(!ignoreCheck && CheckTest(board, flags, 0, ff, 0, k, FALSE)) ft = NoRights;
1563 if(ft != NoRights && board[0][ft] == WhiteRook) {
1564 if(flags & F_FRC_TYPE_CASTLING) callback(board, flags, WhiteASideCastleFR, 0, ff, 0, ft, closure);
1565 if(swap) callback(board, flags, WhiteASideCastleFR, 0, ft, 0, ff, closure);
1569 ff = castlingRights[5]; /* King file if we have any rights */
1570 if(ff != NoRights && board[BOARD_HEIGHT-1][ff] == BlackKing) {
1571 ft = castlingRights[3]; /* Rook file if we have H-side rights */
1573 right = BOARD_RGHT-2;
1574 if(ff == BOARD_RGHT-2) left = right = ff-1; /* special case */
1575 for(k=left; k<=right && ft != NoRights; k++) /* first test if blocked */
1576 if(k != ft && board[BOARD_HEIGHT-1][k] != EmptySquare) ft = NoRights;
1577 for(k=left; k<right && ft != NoRights; k++) /* then if not checked */
1578 if(!ignoreCheck && CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, k, FALSE)) ft = NoRights;
1579 if(ft != NoRights && board[BOARD_HEIGHT-1][ft] == BlackRook) {
1580 if(flags & F_FRC_TYPE_CASTLING) callback(board, flags, BlackHSideCastleFR, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ft, closure);
1581 if(swap) callback(board, flags, BlackHSideCastleFR, BOARD_HEIGHT-1, ft, BOARD_HEIGHT-1, ff, closure);
1584 ft = castlingRights[4]; /* Rook file if we have A-side rights */
1585 left = BOARD_LEFT+2;
1587 if(ff <= BOARD_LEFT+2) { left = ff+1; right = BOARD_LEFT+3; }
1588 for(k=left; k<=right && ft != NoRights; k++) /* first test if blocked */
1589 if(k != ft && board[BOARD_HEIGHT-1][k] != EmptySquare) ft = NoRights;
1590 if(ft == 0 && ff != 1 && board[BOARD_HEIGHT-1][1] != EmptySquare) ft = NoRights; /* Rook can be blocked on b8 */
1591 if(ff > BOARD_LEFT+2)
1592 for(k=left+1; k<=right && ft != NoRights; k++) /* then if not checked */
1593 if(!ignoreCheck && CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, k, FALSE)) ft = NoRights;
1594 if(ft != NoRights && board[BOARD_HEIGHT-1][ft] == BlackRook) {
1595 if(flags & F_FRC_TYPE_CASTLING) callback(board, flags, BlackASideCastleFR, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ft, closure);
1596 if(swap) callback(board, flags, BlackASideCastleFR, BOARD_HEIGHT-1, ft, BOARD_HEIGHT-1, ff, closure);
1613 extern void CheckTestCallback P((Board board, int flags, ChessMove kind,
1614 int rf, int ff, int rt, int ft,
1619 CheckTestCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1621 register CheckTestClosure *cl = (CheckTestClosure *) closure;
1623 if (rt == cl->rking && ft == cl->fking) {
1624 if(xqCheckers[EP_STATUS] >= 2 && xqCheckers[rf][ff]) return; // checker is piece with suspended checking power
1626 xqCheckers[rf][ff] = xqCheckers[EP_STATUS] & 1; // remember who is checking (if status == 1)
1628 if( board[EP_STATUS] == EP_ROYAL_LION && (board[rt][ft] == WhiteLion || board[rt][ft] == BlackLion)
1629 && (gameInfo.variant != VariantLion || board[rf][ff] != WhiteKing && board[rf][ff] != BlackKing) )
1630 cl->check++; // [HGM] lion: forbidden counterstrike against Lion equated to putting yourself in check
1634 /* If the player on move were to move from (rf, ff) to (rt, ft), would
1635 he leave himself in check? Or if rf == -1, is the player on move
1636 in check now? enPassant must be TRUE if the indicated move is an
1637 e.p. capture. The possibility of castling out of a check along the
1638 back rank is not accounted for (i.e., we still return nonzero), as
1639 this is illegal anyway. Return value is the number of times the
1640 king is in check. */
1642 CheckTest (Board board, int flags, int rf, int ff, int rt, int ft, int enPassant)
1644 CheckTestClosure cl;
1645 ChessSquare king = flags & F_WHITE_ON_MOVE ? WhiteKing : BlackKing;
1646 ChessSquare captured = EmptySquare, ep=0, trampled=0;
1647 int saveKill = killX;
1648 /* Suppress warnings on uninitialized variables */
1650 if(gameInfo.variant == VariantXiangqi)
1651 king = flags & F_WHITE_ON_MOVE ? WhiteWazir : BlackWazir;
1652 if(gameInfo.variant == VariantKnightmate)
1653 king = flags & F_WHITE_ON_MOVE ? WhiteUnicorn : BlackUnicorn;
1654 if(gameInfo.variant == VariantChu || gameInfo.variant == VariantShogi) { // strictly speaking this is not needed, as Chu officially has no check
1655 int r, f, k = king, royals=0, prince = flags & F_WHITE_ON_MOVE ? WhiteMonarch : BlackMonarch;
1656 if(gameInfo.variant == VariantShogi) prince -= 11; // White/BlackFalcon
1657 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++) {
1658 if(board[r][f] == k || board[r][f] == prince) {
1659 if(++royals > 1) return FALSE; // no check if we have two royals (ignores double captureby Lion!)
1660 king = board[r][f]; // remember hich one we had
1667 captured = board[rf][ft];
1668 board[rf][ft] = EmptySquare;
1670 captured = board[rt][ft];
1671 if(killX >= 0) { trampled = board[killY][killX]; board[killY][killX] = EmptySquare; killX = -1; }
1673 if(rf == DROP_RANK) board[rt][ft] = ff; else { // [HGM] drop
1674 board[rt][ft] = board[rf][ff];
1675 if(rf != rt || ff != ft) board[rf][ff] = EmptySquare;
1677 ep = board[EP_STATUS];
1678 if( captured == WhiteLion || captured == BlackLion ) { // [HGM] lion: Chu Lion-capture rules
1679 ChessSquare victim = saveKill < 0 ? EmptySquare : trampled;
1680 if( (board[rt][ft] == WhiteLion || board[rt][ft] == BlackLion) && // capturer is Lion
1681 (ff - ft > 1 || ft - ff > 1 || rf - rt > 1 || rt - rf > 1) && // captures from a distance
1682 (victim == EmptySquare || victim == WhitePawn || victim == BlackPawn // no or worthless 'bridge'
1683 || victim == WhiteCobra || victim == BlackCobra) ) // (Pawn or Go Between)
1684 board[EP_STATUS] = EP_ROYAL_LION; // on distant Lion x Lion victim must not be pseudo-legally protected
1688 /* For compatibility with ICS wild 9, we scan the board in the
1689 order a1, a2, a3, ... b1, b2, ..., h8 to find the first king,
1690 and we test only whether that one is in check. */
1691 for (cl.fking = BOARD_LEFT+0; cl.fking < BOARD_RGHT; cl.fking++)
1692 for (cl.rking = 0; cl.rking < BOARD_HEIGHT; cl.rking++) {
1693 if (board[cl.rking][cl.fking] == king) {
1695 if(gameInfo.variant == VariantXiangqi) {
1696 /* [HGM] In Xiangqi opposing Kings means check as well */
1698 dir = (king >= BlackPawn) ? -1 : 1;
1699 for( i=cl.rking+dir; i>=0 && i<BOARD_HEIGHT &&
1700 board[i][cl.fking] == EmptySquare; i+=dir );
1701 if(i>=0 && i<BOARD_HEIGHT &&
1702 board[i][cl.fking] == (dir>0 ? BlackWazir : WhiteWazir) )
1705 GenPseudoLegal(board, flags ^ F_WHITE_ON_MOVE, CheckTestCallback, (VOIDSTAR) &cl, EmptySquare);
1706 if(gameInfo.variant != VariantSpartan || cl.check == 0) // in Spartan Chess go on to test if other King is checked too
1707 goto undo_move; /* 2-level break */
1714 if(rf != DROP_RANK) // [HGM] drop
1715 board[rf][ff] = board[rt][ft];
1717 board[rf][ft] = captured;
1718 board[rt][ft] = EmptySquare;
1720 if(saveKill >= 0) board[killY][killX = saveKill] = trampled;
1721 board[rt][ft] = captured;
1723 board[EP_STATUS] = ep;
1726 return cl.fking < BOARD_RGHT ? cl.check : 1000; // [HGM] atomic: return 1000 if we have no king
1730 HasLion (Board board, int flags)
1732 int lion = F_WHITE_ON_MOVE & flags ? WhiteLion : BlackLion;
1734 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++)
1735 if(board[r][f] == lion) return 1;
1740 LegalDrop (Board board, int flags, ChessSquare piece, int rt, int ft)
1741 { // [HGM] put drop legality testing in separate routine for clarity
1743 if(appData.debugMode) fprintf(debugFP, "LegalDrop: %d @ %d,%d)\n", piece, ft, rt);
1744 if(board[rt][ft] != EmptySquare) return ImpossibleMove; // must drop to empty square
1745 n = PieceToNumber(piece);
1746 if((gameInfo.holdingsWidth == 0 || (flags & F_WHITE_ON_MOVE ? board[n][BOARD_WIDTH-1] : board[BOARD_HEIGHT-1-n][0]) != piece)
1747 && gameInfo.variant != VariantBughouse) // in bughouse we don't check for availability, because ICS doesn't always tell us
1748 return ImpossibleMove; // piece not available
1749 if(gameInfo.variant == VariantShogi) { // in Shogi lots of drops are forbidden!
1750 if((piece == WhitePawn || piece == WhiteQueen) && rt == BOARD_HEIGHT-1 ||
1751 (piece == BlackPawn || piece == BlackQueen) && rt == 0 ||
1752 piece == WhiteKnight && rt > BOARD_HEIGHT-3 ||
1753 piece == BlackKnight && rt < 2 ) return IllegalMove; // e.g. where dropped piece has no moves
1754 if(piece == WhitePawn || piece == BlackPawn) {
1755 int r, max = 1 + (BOARD_HEIGHT == 7); // two Pawns per file in Tori!
1756 for(r=1; r<BOARD_HEIGHT-1; r++)
1757 if(!(max -= (board[r][ft] == piece))) return IllegalMove; // or there already is a Pawn in file
1758 // should still test if we mate with this Pawn
1760 } else if(gameInfo.variant == VariantSChess) { // only back-rank drops
1761 if (rt != (piece < BlackPawn ? 0 : BOARD_HEIGHT-1)) return IllegalMove;
1763 if( (piece == WhitePawn || piece == BlackPawn) &&
1764 (rt == 0 || rt == BOARD_HEIGHT -1 ) )
1765 return IllegalMove; /* no pawn drops on 1st/8th */
1767 if(appData.debugMode) fprintf(debugFP, "LegalDrop: %d @ %d,%d)\n", piece, ft, rt);
1768 if (!(flags & F_IGNORE_CHECK) &&
1769 CheckTest(board, flags, DROP_RANK, piece, rt, ft, FALSE) ) return IllegalMove;
1770 return flags & F_WHITE_ON_MOVE ? WhiteDrop : BlackDrop;
1773 extern void LegalityTestCallback P((Board board, int flags, ChessMove kind,
1774 int rf, int ff, int rt, int ft,
1778 LegalityTestCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1780 register LegalityTestClosure *cl = (LegalityTestClosure *) closure;
1782 if(board[rt][ft] != EmptySquare || kind==WhiteCapturesEnPassant || kind==BlackCapturesEnPassant)
1783 cl->captures++; // [HGM] losers: count legal captures
1784 if (rf == cl->rf && ff == cl->ff && rt == cl->rt && ft == cl->ft)
1789 LegalityTest (Board board, int flags, int rf, int ff, int rt, int ft, int promoChar)
1791 LegalityTestClosure cl; ChessSquare piece, filterPiece;
1793 if(quickFlag) flags = flags & ~1 | quickFlag & 1; // [HGM] speed: in quick mode quickFlag specifies side-to-move.
1794 if(rf == DROP_RANK) return LegalDrop(board, flags, ff, rt, ft);
1795 piece = filterPiece = board[rf][ff];
1796 if(PieceToChar(piece) == '~') filterPiece = DEMOTED(piece);
1798 /* [HGM] Cobra and Falcon are wildcard pieces; consider all their moves legal */
1799 /* (perhaps we should disallow moves that obviously leave us in check?) */
1800 if((piece == WhiteFalcon || piece == BlackFalcon ||
1801 piece == WhiteCobra || piece == BlackCobra) && gameInfo.variant != VariantChu && !pieceDesc[piece])
1802 return CheckTest(board, flags, rf, ff, rt, ft, FALSE) ? IllegalMove : NormalMove;
1806 cl.rt = rFilter = rt; // [HGM] speed: filter on to-square
1807 cl.ft = fFilter = ft;
1808 cl.kind = IllegalMove;
1809 cl.captures = 0; // [HGM] losers: prepare to count legal captures.
1810 if(flags & F_MANDATORY_CAPTURE) filterPiece = EmptySquare; // [HGM] speed: do not filter in suicide, to find all captures
1811 GenLegal(board, flags, LegalityTestCallback, (VOIDSTAR) &cl, filterPiece);
1812 if((flags & F_MANDATORY_CAPTURE) && cl.captures && board[rt][ft] == EmptySquare
1813 && cl.kind != WhiteCapturesEnPassant && cl.kind != BlackCapturesEnPassant)
1814 return(IllegalMove); // [HGM] losers: if there are legal captures, non-capts are illegal
1816 if(promoChar == 'x') promoChar = NULLCHAR; // [HGM] is this ever the case?
1817 if(gameInfo.variant == VariantSChess && promoChar && promoChar != '=' && board[rf][ff] != WhitePawn && board[rf][ff] != BlackPawn) {
1818 if(board[rf][ff] < BlackPawn) { // white
1819 if(rf != 0) return IllegalMove; // must be on back rank
1820 if(!(board[VIRGIN][ff] & VIRGIN_W)) return IllegalMove; // non-virgin
1821 if(board[PieceToNumber(CharToPiece(ToUpper(promoChar)))][BOARD_WIDTH-2] == 0) return ImpossibleMove;// must be in stock
1822 if(cl.kind == WhiteHSideCastleFR && (ff == BOARD_RGHT-2 || ff == BOARD_RGHT-3)) return ImpossibleMove;
1823 if(cl.kind == WhiteASideCastleFR && (ff == BOARD_LEFT+2 || ff == BOARD_LEFT+3)) return ImpossibleMove;
1825 if(rf != BOARD_HEIGHT-1) return IllegalMove;
1826 if(!(board[VIRGIN][ff] & VIRGIN_B)) return IllegalMove; // non-virgin
1827 if(board[BOARD_HEIGHT-1-PieceToNumber(CharToPiece(ToLower(promoChar)))][1] == 0) return ImpossibleMove;
1828 if(cl.kind == BlackHSideCastleFR && (ff == BOARD_RGHT-2 || ff == BOARD_RGHT-3)) return ImpossibleMove;
1829 if(cl.kind == BlackASideCastleFR && (ff == BOARD_LEFT+2 || ff == BOARD_LEFT+3)) return ImpossibleMove;
1832 if(gameInfo.variant == VariantChu) {
1833 if(cl.kind != NormalMove || promoChar == NULLCHAR || promoChar == '=') return cl.kind;
1834 if(promoChar != '+')
1835 return CharToPiece(promoChar) == EmptySquare ? ImpossibleMove : IllegalMove;
1836 if(PieceToChar(CHUPROMOTED(board[rf][ff])) != '+') {
1837 if(PieceToChar(CHUPROMOTED (board[rf][ff] < BlackPawn ? WhitePawn : BlackPawn)) != '.')
1838 return ImpossibleMove;
1840 return flags & F_WHITE_ON_MOVE ? WhitePromotion : BlackPromotion;
1842 if(gameInfo.variant == VariantShogi) {
1843 /* [HGM] Shogi promotions. '=' means defer */
1844 if(rf != DROP_RANK && cl.kind == NormalMove) {
1845 ChessSquare piece = board[rf][ff];
1846 int zone = BOARD_HEIGHT/3 + (BOARD_HEIGHT == 8);
1848 if(promoChar == PieceToChar(BlackQueen)) promoChar = NULLCHAR; /* [HGM] Kludge */
1849 if(promoChar == 'd' && (piece == WhiteRook || piece == BlackRook) ||
1850 promoChar == 'h' && (piece == WhiteBishop || piece == BlackBishop) ||
1851 promoChar == 'g' && (piece <= WhiteFerz || piece <= BlackFerz && piece >= BlackPawn) )
1852 promoChar = '+'; // allowed ICS notations
1853 if(appData.debugMode)fprintf(debugFP,"SHOGI promoChar = %c\n", promoChar ? promoChar : '-');
1854 if(promoChar != NULLCHAR && promoChar != '+' && promoChar != '=')
1855 return CharToPiece(promoChar) == EmptySquare ? ImpossibleMove : IllegalMove;
1856 else if(flags & F_WHITE_ON_MOVE) {
1857 if( (int) piece < (int) WhiteWazir &&
1858 (rf >= BOARD_HEIGHT - zone || rt >= BOARD_HEIGHT - zone) ) {
1859 if( (piece == WhitePawn || piece == WhiteQueen) && rt > BOARD_HEIGHT-2 ||
1860 piece == WhiteKnight && rt > BOARD_HEIGHT-3) /* promotion mandatory */
1861 cl.kind = promoChar == '=' ? IllegalMove : WhitePromotion;
1862 else /* promotion optional, default is defer */
1863 cl.kind = promoChar == '+' ? WhitePromotion : WhiteNonPromotion;
1864 } else cl.kind = promoChar == '+' ? IllegalMove : NormalMove;
1866 if( (int) piece < (int) BlackWazir && (rf < zone || rt < zone) ) {
1867 if( (piece == BlackPawn || piece == BlackQueen) && rt < 1 ||
1868 piece == BlackKnight && rt < 2 ) /* promotion obligatory */
1869 cl.kind = promoChar == '=' ? IllegalMove : BlackPromotion;
1870 else /* promotion optional, default is defer */
1871 cl.kind = promoChar == '+' ? BlackPromotion : BlackNonPromotion;
1872 } else cl.kind = promoChar == '+' ? IllegalMove : NormalMove;
1876 if (promoChar != NULLCHAR) {
1877 if(cl.kind == NormalMove && promoChar == '+') { // allow shogi-style promotion is pieceToChar specifies them
1878 ChessSquare piece = board[rf][ff];
1879 if(piece < BlackPawn ? piece > WhiteMan : piece > BlackMan) return ImpossibleMove; // already promoted
1880 // should test if in zone, really
1881 if(gameInfo.variant == VariantChuChess && (piece == WhiteKnight || piece == BlackKnight) && HasLion(board, flags))
1883 if(PieceToChar(PROMOTED(piece)) == '+') return flags & F_WHITE_ON_MOVE ? WhitePromotion : BlackPromotion;
1885 if(promoChar == '=') cl.kind = IllegalMove; else // [HGM] shogi: no deferred promotion outside Shogi
1886 if (cl.kind == WhitePromotion || cl.kind == BlackPromotion) {
1887 ChessSquare piece = CharToPiece(flags & F_WHITE_ON_MOVE ? ToUpper(promoChar) : ToLower(promoChar));
1888 if(piece == EmptySquare)
1889 cl.kind = ImpossibleMove; // non-existing piece
1890 if(gameInfo.variant == VariantChuChess && promoChar == 'l' && HasLion(board, flags)) {
1891 cl.kind = IllegalMove; // no two Lions
1892 } else if(gameInfo.variant == VariantSpartan && cl.kind == BlackPromotion ) {
1893 if(promoChar != PieceToChar(BlackKing)) {
1894 if(CheckTest(board, flags, rf, ff, rt, ft, FALSE)) cl.kind = IllegalMove; // [HGM] spartan: only promotion to King was possible
1895 if(piece == BlackLance) cl.kind = ImpossibleMove;
1896 } else { // promotion to King allowed only if we do not have two yet
1897 int r, f, kings = 0;
1898 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++) kings += (board[r][f] == BlackKing);
1899 if(kings == 2) cl.kind = IllegalMove;
1901 } else if(piece == WhitePawn && rt == BOARD_HEIGHT-1 ||
1902 piece == BlackPawn && rt == 0) cl.kind = IllegalMove; // cannot stay Pawn on last rank in any variant
1903 else if((piece == WhiteUnicorn || piece == BlackUnicorn) && gameInfo.variant == VariantKnightmate)
1904 cl.kind = IllegalMove; // promotion to Royal Knight not allowed
1905 else if((piece == WhiteKing || piece == BlackKing) && gameInfo.variant != VariantSuicide && gameInfo.variant != VariantGiveaway)
1906 cl.kind = IllegalMove; // promotion to King usually not allowed
1908 cl.kind = IllegalMove;
1918 extern void MateTestCallback P((Board board, int flags, ChessMove kind,
1919 int rf, int ff, int rt, int ft,
1923 MateTestCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1925 register MateTestClosure *cl = (MateTestClosure *) closure;
1930 /* Return MT_NONE, MT_CHECK, MT_CHECKMATE, or MT_STALEMATE */
1932 MateTest (Board board, int flags)
1935 int inCheck, r, f, myPieces=0, hisPieces=0, nrKing=0;
1936 ChessSquare king = flags & F_WHITE_ON_MOVE ? WhiteKing : BlackKing;
1938 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++) {
1939 // [HGM] losers: Count pieces and kings, to detect other unorthodox winning conditions
1940 nrKing += (board[r][f] == king); // stm has king
1941 if( board[r][f] != EmptySquare ) {
1942 if((int)board[r][f] <= (int)king && (int)board[r][f] >= (int)king - (int)WhiteKing + (int)WhitePawn)
1947 switch(gameInfo.variant) { // [HGM] losers: extinction wins
1948 case VariantShatranj:
1949 if(hisPieces == 1) return myPieces > 1 ? MT_BARE : MT_DRAW;
1953 if(nrKing == 0) return MT_NOKING;
1956 if(myPieces == 1) return MT_BARE;
1959 inCheck = GenLegal(board, flags, MateTestCallback, (VOIDSTAR) &cl, EmptySquare);
1960 // [HGM] 3check: yet to do!
1962 return inCheck ? MT_CHECK : MT_NONE;
1964 if(gameInfo.holdingsWidth && gameInfo.variant != VariantSuper && gameInfo.variant != VariantGreat
1965 && gameInfo.variant != VariantSChess && gameInfo.variant != VariantGrand) { // drop game
1966 int r, f, n, holdings = flags & F_WHITE_ON_MOVE ? BOARD_WIDTH-1 : 0;
1967 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++) if(board[r][f] == EmptySquare) // all empty squares
1968 for(n=0; n<BOARD_HEIGHT; n++) // all pieces in hand
1969 if(board[n][holdings] != EmptySquare) {
1970 int moveType = LegalDrop(board, flags, board[n][holdings], r, f);
1971 if(moveType == WhiteDrop || moveType == BlackDrop) return (inCheck ? MT_CHECK : MT_NONE); // we have legal drop
1974 if(gameInfo.variant == VariantSuicide) // [HGM] losers: always stalemate, since no check, but result varies
1975 return myPieces == hisPieces ? MT_STALEMATE :
1976 myPieces > hisPieces ? MT_STAINMATE : MT_STEALMATE;
1977 else if(gameInfo.variant == VariantLosers) return inCheck ? MT_TRICKMATE : MT_STEALMATE;
1978 else if(gameInfo.variant == VariantGiveaway) return MT_STEALMATE; // no check exists, stalemated = win
1980 return inCheck ? MT_CHECKMATE
1981 : (gameInfo.variant == VariantXiangqi || gameInfo.variant == VariantShatranj || IS_SHOGI(gameInfo.variant)) ?
1982 MT_STAINMATE : MT_STALEMATE;
1987 extern void DisambiguateCallback P((Board board, int flags, ChessMove kind,
1988 int rf, int ff, int rt, int ft,
1992 DisambiguateCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1994 register DisambiguateClosure *cl = (DisambiguateClosure *) closure;
1995 int wildCard = FALSE; ChessSquare piece = board[rf][ff];
1996 extern int kifu; // in parser.c
1998 // [HGM] wild: for wild-card pieces rt and rf are dummies
1999 if(piece == WhiteFalcon || piece == BlackFalcon ||
2000 piece == WhiteCobra || piece == BlackCobra)
2003 if ((cl->pieceIn == EmptySquare || cl->pieceIn == board[rf][ff]
2004 || PieceToChar(board[rf][ff]) == '~'
2005 && cl->pieceIn == (ChessSquare)(DEMOTED(board[rf][ff]))
2007 (cl->rfIn == -1 || cl->rfIn == rf) &&
2008 (cl->ffIn == -1 || cl->ffIn == ff) &&
2009 (cl->rtIn == -1 || cl->rtIn == rt || wildCard) &&
2010 (cl->ftIn == -1 || cl->ftIn == ft || wildCard)) {
2012 if(cl->count && rf == cl->rf && ff == cl->ff) return; // duplicate move
2014 if(cl->count == 1 && kifu & 0x7E && cl->rfIn == -1 && cl->ffIn == -1) { // traditional Shogi disambiguation required
2015 int this = 1, other = 1;
2016 if(kifu & 2) this &= (flags & 1 ? rt > rf : rt < rf), other &= (flags & 1 ? cl->rt > cl->rf : cl->rt < cl->rf);
2017 if(kifu & 4) this &= (flags & 1 ? rt < rf : rt > rf), other &= (flags & 1 ? cl->rt < cl->rf : cl->rt > cl->rf);
2018 if(kifu & 8) this &= (rf == rt), other &= (cl->rt == cl->rf);
2019 if(kifu & 0x10) this &= (flags & 1 ? ft <= ff : ft >= ff), other &= (flags & 1 ? cl->ft <= cl->ff : cl->ft >= cl->ff);
2020 if(kifu & 0x20) this &= (flags & 1 ? ft >= ff : ft <= ff), other &= (flags & 1 ? cl->ft >= cl->ff : cl->ft <= cl->ff);
2021 if(kifu & 0x40) this &= (ft == ff), other &= (cl->ft == cl->ff); // should never be used
2022 if(!other) cl->count--; // the old move did not satisfy the requested relative position, erase it
2023 if(!this) return; // the current move does not satisfy the requested relative position, ignore it
2027 if(cl->count == 1 || board[rt][ft] != EmptySquare) {
2028 // [HGM] oneclick: if multiple moves, be sure we remember capture
2029 cl->piece = board[rf][ff];
2032 cl->rt = wildCard ? cl->rtIn : rt;
2033 cl->ft = wildCard ? cl->ftIn : ft;
2036 cl->captures += (board[rt][ft] != EmptySquare); // [HGM] oneclick: count captures
2041 Disambiguate (Board board, int flags, DisambiguateClosure *closure)
2043 int illegal = 0; char c = closure->promoCharIn;
2045 if(quickFlag) flags = flags & ~1 | quickFlag & 1; // [HGM] speed: in quick mode quickFlag specifies side-to-move.
2046 closure->count = closure->captures = 0;
2047 closure->rf = closure->ff = closure->rt = closure->ft = 0;
2048 closure->kind = ImpossibleMove;
2049 rFilter = closure->rtIn; // [HGM] speed: only consider moves to given to-square
2050 fFilter = closure->ftIn;
2051 if(quickFlag) { // [HGM] speed: try without check test first, because if that is not ambiguous, we are happy
2052 GenLegal(board, flags|F_IGNORE_CHECK, DisambiguateCallback, (VOIDSTAR) closure, closure->pieceIn);
2053 if(closure->count > 1) { // gamble did not pay off. retry with check test to resolve ambiguity
2054 closure->count = closure->captures = 0;
2055 closure->rf = closure->ff = closure->rt = closure->ft = 0;
2056 closure->kind = ImpossibleMove;
2057 GenLegal(board, flags, DisambiguateCallback, (VOIDSTAR) closure, closure->pieceIn); // [HGM] speed: only pieces of requested type
2060 GenLegal(board, flags, DisambiguateCallback, (VOIDSTAR) closure, closure->pieceIn); // [HGM] speed: only pieces of requested type
2061 if (closure->count == 0) {
2062 /* See if it's an illegal move due to check */
2064 GenLegal(board, flags|F_IGNORE_CHECK, DisambiguateCallback, (VOIDSTAR) closure, closure->pieceIn);
2065 if (closure->count == 0) {
2066 /* No, it's not even that */
2067 if(!appData.testLegality && !pieceDefs && closure->pieceIn != EmptySquare) {
2068 int f, r; // if there is only a single piece of the requested type on the board, use that
2069 closure->rt = closure->rtIn, closure->ft = closure->ftIn;
2070 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++)
2071 if(board[r][f] == closure->pieceIn) closure->count++, closure->rf = r, closure->ff = f;
2072 if(closure->count > 1) illegal = 0; // ambiguous
2074 if(closure->count == 0) {
2075 if (appData.debugMode) { int i, j;
2076 for(i=BOARD_HEIGHT-1; i>=0; i--) {
2077 for(j=0; j<BOARD_WIDTH; j++)
2078 fprintf(debugFP, "%3d", (int) board[i][j]);
2079 fprintf(debugFP, "\n");
2085 } else if(pieceDefs && closure->count > 1) { // [HGM] gen: move is ambiguous under engine-defined rules
2086 DisambiguateClosure spare = *closure;
2087 pieceDefs = FALSE; spare.count = 0; // See if the (erroneous) built-in rules would resolve that
2088 GenLegal(board, flags, DisambiguateCallback, (VOIDSTAR) &spare, closure->pieceIn);
2089 if(spare.count == 1) *closure = spare; // It does, so use those in stead (game from file saved before gen patch?)
2093 if (c == 'x') c = NULLCHAR; // get rid of any 'x' (which should never happen?)
2094 if(gameInfo.variant == VariantSChess && c && c != '=' && closure->piece != WhitePawn && closure->piece != BlackPawn) {
2095 if(closure->piece < BlackPawn) { // white
2096 if(closure->rf != 0) closure->kind = IllegalMove; // must be on back rank
2097 if(!(board[VIRGIN][closure->ff] & VIRGIN_W)) closure->kind = IllegalMove; // non-virgin
2098 if(board[PieceToNumber(CharToPiece(ToUpper(c)))][BOARD_WIDTH-2] == 0) closure->kind = ImpossibleMove;// must be in stock
2099 if(closure->kind == WhiteHSideCastleFR && (closure->ff == BOARD_RGHT-2 || closure->ff == BOARD_RGHT-3)) closure->kind = ImpossibleMove;
2100 if(closure->kind == WhiteASideCastleFR && (closure->ff == BOARD_LEFT+2 || closure->ff == BOARD_LEFT+3)) closure->kind = ImpossibleMove;
2102 if(closure->rf != BOARD_HEIGHT-1) closure->kind = IllegalMove;
2103 if(!(board[VIRGIN][closure->ff] & VIRGIN_B)) closure->kind = IllegalMove; // non-virgin
2104 if(board[BOARD_HEIGHT-1-PieceToNumber(CharToPiece(ToLower(c)))][1] == 0) closure->kind = ImpossibleMove;
2105 if(closure->kind == BlackHSideCastleFR && (closure->ff == BOARD_RGHT-2 || closure->ff == BOARD_RGHT-3)) closure->kind = ImpossibleMove;
2106 if(closure->kind == BlackASideCastleFR && (closure->ff == BOARD_LEFT+2 || closure->ff == BOARD_LEFT+3)) closure->kind = ImpossibleMove;
2109 if(gameInfo.variant == VariantChu) {
2110 if(c == '+') closure->kind = (flags & F_WHITE_ON_MOVE ? WhitePromotion : BlackPromotion); // for now, accept any
2112 if(gameInfo.variant == VariantShogi) {
2113 /* [HGM] Shogi promotions. On input, '=' means defer, '+' promote. Afterwards, c is set to '+' for promotions, NULL other */
2114 if(closure->rfIn != DROP_RANK && closure->kind == NormalMove) {
2115 ChessSquare piece = closure->piece;
2116 int zone = BOARD_HEIGHT/3 + (BOARD_HEIGHT == 8);
2117 if (c == 'd' && (piece == WhiteRook || piece == BlackRook) ||
2118 c == 'h' && (piece == WhiteBishop || piece == BlackBishop) ||
2119 c == 'g' && (piece <= WhiteFerz || piece <= BlackFerz && piece >= BlackPawn) )
2120 c = '+'; // allowed ICS notations
2121 if(c != NULLCHAR && c != '+' && c != '=') closure->kind = IllegalMove; // otherwise specifying a piece is illegal
2122 else if(flags & F_WHITE_ON_MOVE) {
2123 if( (int) piece < (int) WhiteWazir &&
2124 (closure->rf >= BOARD_HEIGHT-zone || closure->rt >= BOARD_HEIGHT-zone) ) {
2125 if( (piece == WhitePawn || piece == WhiteQueen) && closure->rt > BOARD_HEIGHT-2 ||
2126 piece == WhiteKnight && closure->rt > BOARD_HEIGHT-3) /* promotion mandatory */
2127 closure->kind = c == '=' ? IllegalMove : WhitePromotion;
2128 else /* promotion optional, default is defer */
2129 closure->kind = c == '+' ? WhitePromotion : WhiteNonPromotion;
2130 } else closure->kind = c == '+' ? IllegalMove : NormalMove;
2132 if( (int) piece < (int) BlackWazir && (closure->rf < zone || closure->rt < zone) ) {
2133 if( (piece == BlackPawn || piece == BlackQueen) && closure->rt < 1 ||
2134 piece == BlackKnight && closure->rt < 2 ) /* promotion obligatory */
2135 closure->kind = c == '=' ? IllegalMove : BlackPromotion;
2136 else /* promotion optional, default is defer */
2137 closure->kind = c == '+' ? BlackPromotion : BlackNonPromotion;
2138 } else closure->kind = c == '+' ? IllegalMove : NormalMove;
2141 if(closure->kind == WhitePromotion || closure->kind == BlackPromotion) c = '+'; else
2142 if(closure->kind == WhiteNonPromotion || closure->kind == BlackNonPromotion) c = '=';
2144 if (closure->kind == WhitePromotion || closure->kind == BlackPromotion) {
2145 if(c == NULLCHAR) { // missing promoChar on mandatory promotion; use default for variant
2146 if(gameInfo.variant == VariantShatranj || gameInfo.variant == VariantCourier ||
2147 gameInfo.variant == VariantMakruk)
2148 c = PieceToChar(BlackFerz);
2149 else if(gameInfo.variant == VariantASEAN)
2150 c = PieceToChar(BlackRook);
2151 else if(gameInfo.variant == VariantGreat)
2152 c = PieceToChar(BlackMan);
2153 else if(gameInfo.variant == VariantGrand)
2154 closure->kind = closure->rt != 0 && closure->rt != BOARD_HEIGHT-1 ? NormalMove : AmbiguousMove; // no default in Grand Chess
2156 c = PieceToChar(BlackQueen);
2157 } else if(c == '=') closure->kind = IllegalMove; // no deferral outside Shogi
2158 else if(c == 'l' && gameInfo.variant == VariantChuChess && HasLion(board, flags)) closure->kind = IllegalMove;
2159 } else if (c == '+') { // '+' outside shogi, check if pieceToCharTable enabled it
2160 ChessSquare p = closure->piece;
2161 if(p > WhiteMan && p < BlackPawn || p > BlackMan || PieceToChar(PROMOTED(p)) != '+')
2162 closure->kind = ImpossibleMove; // used on non-promotable piece
2163 else if(gameInfo.variant == VariantChuChess && HasLion(board, flags)) closure->kind = IllegalMove;
2164 } else if (c != NULLCHAR) closure->kind = IllegalMove;
2166 closure->promoChar = ToLower(c); // this can be NULLCHAR! Note we keep original promoChar even if illegal.
2167 if(c != '+' && c != '=' && c != NULLCHAR && CharToPiece(flags & F_WHITE_ON_MOVE ? ToUpper(c) : ToLower(c)) == EmptySquare)
2168 closure->kind = ImpossibleMove; // but we cannot handle non-existing piece types!
2169 if (closure->count > 1) {
2170 closure->kind = AmbiguousMove;
2173 /* Note: If more than one illegal move matches, but no legal
2174 moves, we return IllegalMove, not AmbiguousMove. Caller
2175 can look at closure->count to detect this.
2177 closure->kind = IllegalMove;
2191 } CoordsToAlgebraicClosure;
2193 extern void CoordsToAlgebraicCallback P((Board board, int flags,
2194 ChessMove kind, int rf, int ff,
2195 int rt, int ft, VOIDSTAR closure));
2198 CoordsToAlgebraicCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
2200 register CoordsToAlgebraicClosure *cl =
2201 (CoordsToAlgebraicClosure *) closure;
2203 if ((rt == cl->rt && ft == cl->ft || rt == rf && ft == ff) && // [HGM] null move matches any toSquare
2204 (board[rf][ff] == cl->piece
2205 || PieceToChar(board[rf][ff]) == '~' &&
2206 (ChessSquare) (DEMOTED(board[rf][ff])) == cl->piece)
2210 cl->kind = kind; /* this is the move we want */
2212 cl->file++; /* need file to rule out this move */
2216 cl->rank++; /* need rank to rule out this move */
2218 cl->either++; /* rank or file will rule out this move */
2224 /* Convert coordinates to normal algebraic notation.
2225 promoChar must be NULLCHAR or 'x' if not a promotion.
2228 CoordsToAlgebraic (Board board, int flags, int rf, int ff, int rt, int ft, int promoChar, char out[MOVE_LEN])
2232 char *outp = out, c, capture;
2233 CoordsToAlgebraicClosure cl;
2235 if (rf == DROP_RANK) {
2236 if(ff == EmptySquare) { strncpy(outp, "--",3); return NormalMove; } // [HGM] pass
2237 /* Bughouse piece drop */
2238 *outp++ = ToUpper(PieceToChar((ChessSquare) ff));
2243 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2245 return (flags & F_WHITE_ON_MOVE) ? WhiteDrop : BlackDrop;
2248 if (promoChar == 'x') promoChar = NULLCHAR;
2249 piece = board[rf][ff];
2250 if(PieceToChar(piece)=='~') piece = (ChessSquare)(DEMOTED(piece));
2255 kind = LegalityTest(board, flags, rf, ff, rt, ft, promoChar);
2256 if (kind == IllegalMove && !(flags&F_IGNORE_CHECK)) {
2257 /* Keep short notation if move is illegal only because it
2258 leaves the player in check, but still return IllegalMove */
2259 kind = LegalityTest(board, flags|F_IGNORE_CHECK, rf, ff, rt, ft, promoChar);
2260 if (kind == IllegalMove) break;
2265 capture = board[rt][ft] != EmptySquare || kind == WhiteCapturesEnPassant || kind == BlackCapturesEnPassant;
2266 if (ff == ft && !capture) { /* [HGM] Xiangqi has straight noncapts! */
2267 /* Non-capture; use style "e5" */
2270 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2272 /* Capture; use style "exd5" */
2274 *outp++ = 'x'; /* [HGM] Xiangqi has sideway noncaptures across river! */
2278 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2280 /* Use promotion suffix style "=Q" */
2282 if (promoChar != NULLCHAR) {
2283 if(IS_SHOGI(gameInfo.variant)) {
2284 /* [HGM] ... but not in Shogi! */
2285 *outp++ = promoChar == '=' ? '=' : '+';
2288 *outp++ = ToUpper(promoChar);
2297 /* Fabien moved code: FRC castling first (if KxR), wild castling second */
2298 /* Code added by Tord: FRC castling. */
2299 if((piece == WhiteKing && board[rt][ft] == WhiteRook) ||
2300 (piece == BlackKing && board[rt][ft] == BlackRook)) {
2302 safeStrCpy(out, "O-O", MOVE_LEN);
2304 safeStrCpy(out, "O-O-O", MOVE_LEN);
2305 return LegalityTest(board, flags, rf, ff, rt, ft, promoChar);
2307 /* End of code added by Tord */
2308 /* Test for castling or ICS wild castling */
2309 /* Use style "O-O" (oh-oh) for PGN compatibility */
2310 else if (rf == rt &&
2311 rf == ((piece == WhiteKing) ? 0 : BOARD_HEIGHT-1) &&
2312 (ft - ff > 1 || ff - ft > 1) && // No castling if legal King move (on narrow boards!)
2313 ((ff == BOARD_WIDTH>>1 && (ft == BOARD_LEFT+2 || ft == BOARD_RGHT-2)) ||
2314 (ff == (BOARD_WIDTH-1)>>1 && (ft == BOARD_LEFT+1 || ft == BOARD_RGHT-3)))) {
2315 if(ft==BOARD_LEFT+1 || ft==BOARD_RGHT-2)
2316 snprintf(out, MOVE_LEN, "O-O%c%c", promoChar ? '/' : 0, ToUpper(promoChar));
2318 snprintf(out, MOVE_LEN, "O-O-O%c%c", promoChar ? '/' : 0, ToUpper(promoChar));
2320 /* This notation is always unambiguous, unless there are
2321 kings on both the d and e files, with "wild castling"
2322 possible for the king on the d file and normal castling
2323 possible for the other. ICS rules for wild 9
2324 effectively make castling illegal for either king in
2325 this situation. So I am not going to worry about it;
2326 I'll just generate an ambiguous O-O in this case.
2328 return LegalityTest(board, flags, rf, ff, rt, ft, promoChar);
2331 /* else fall through */
2336 cl.rt = rFilter = rt; // [HGM] speed: filter on to-square
2337 cl.ft = fFilter = ft;
2339 cl.kind = IllegalMove;
2340 cl.rank = cl.file = cl.either = 0;
2341 c = PieceToChar(piece) ;
2342 GenLegal(board, flags, CoordsToAlgebraicCallback, (VOIDSTAR) &cl, c!='~' ? piece : (DEMOTED(piece))); // [HGM] speed
2344 if (cl.kind == IllegalMove && !(flags&F_IGNORE_CHECK)) {
2345 /* Generate pretty moves for moving into check, but
2346 still return IllegalMove.
2348 GenLegal(board, flags|F_IGNORE_CHECK, CoordsToAlgebraicCallback, (VOIDSTAR) &cl, c!='~' ? piece : (DEMOTED(piece)));
2349 if (cl.kind == IllegalMove) break;
2350 cl.kind = IllegalMove;
2353 /* Style is "Nf3" or "Nxf7" if this is unambiguous,
2354 else "Ngf3" or "Ngxf7",
2355 else "N1f3" or "N5xf7",
2356 else "Ng1f3" or "Ng5xf7".
2358 if( c == '~' || c == '+') {
2359 /* [HGM] print nonexistent piece as its demoted version */
2360 piece = (ChessSquare) (CHUDEMOTED(piece));
2362 if(c=='+') *outp++ = c;
2363 *outp++ = ToUpper(PieceToChar(piece));
2364 if(*outp = PieceSuffix(piece)) outp++;
2366 if (cl.file || (cl.either && !cl.rank)) {
2372 else { *outp++ = (rf+ONE-'0')/10 + '0';*outp++ = (rf+ONE-'0')%10 + '0'; }
2375 if(board[rt][ft] != EmptySquare)
2381 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2382 if (IS_SHOGI(gameInfo.variant)) {
2383 /* [HGM] in Shogi non-pawns can promote */
2384 *outp++ = promoChar; // Don't bother to correct move type, return value is never used!
2386 else if (gameInfo.variant == VariantChuChess && promoChar ||
2387 gameInfo.variant != VariantSuper && promoChar &&
2388 (piece == WhiteLance || piece == BlackLance) ) { // Lance sometimes represents Pawn
2390 *outp++ = ToUpper(promoChar);
2392 else if (gameInfo.variant == VariantSChess && promoChar) { // and in S-Chess we have gating
2394 *outp++ = ToUpper(promoChar);
2400 /* Moving a nonexistent piece */
2404 /* Not a legal move, even ignoring check.
2405 If there was a piece on the from square,
2406 use style "Ng1g3" or "Ng1xe8";
2407 if there was a pawn or nothing (!),
2408 use style "g1g3" or "g1xe8". Use "x"
2409 if a piece was on the to square, even
2410 a piece of the same color.
2414 if (piece != EmptySquare && piece != WhitePawn && piece != BlackPawn) {
2416 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<=BOARD_RGHT; f++)
2417 c += (board[r][f] == piece); // count on-board pieces of given type
2418 *outp++ = ToUpper(PieceToChar(piece));
2420 if(c != 1) { // [HGM] but if there is only one piece of the mentioned type, no from-square, thank you!
2424 else { *outp++ = (rf+ONE-'0')/10 + '0';*outp++ = (rf+ONE-'0')%10 + '0'; }
2426 if (board[rt][ft] != EmptySquare) *outp++ = 'x';
2430 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2431 /* Use promotion suffix style "=Q" */
2432 if (promoChar != NULLCHAR && promoChar != 'x') {
2434 *outp++ = ToUpper(promoChar);
2441 // [HGM] XQ: the following code serves to detect perpetual chasing (Asian rules)
2450 // I guess the following variables logically belong in the closure too, but I was too lazy and used globals
2452 int preyStackPointer, chaseStackPointer;
2455 unsigned char rf, ff, rt, ft;
2459 unsigned char rank, file;
2465 // there are three new callbacks for use with GenLegal: for adding captures, deleting them, and finding a recapture
2467 extern void AtacksCallback P((Board board, int flags, ChessMove kind,
2468 int rf, int ff, int rt, int ft,
2472 AttacksCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
2473 { // For adding captures that can lead to chase indictment to the chaseStack
2474 if(board[rt][ft] == EmptySquare) return; // non-capture
2475 if(board[rt][ft] == WhitePawn && rt < BOARD_HEIGHT/2) return; // Pawn before river can be chased
2476 if(board[rt][ft] == BlackPawn && rt >= BOARD_HEIGHT/2) return; // Pawn before river can be chased
2477 if(board[rf][ff] == WhitePawn || board[rf][ff] == BlackPawn) return; // Pawns are allowed to chase
2478 if(board[rf][ff] == WhiteWazir || board[rf][ff] == BlackWazir) return; // King is allowed to chase
2479 // move cannot be excluded from being a chase trivially (based on attacker and victim); save it on chaseStack
2480 chaseStack[chaseStackPointer].rf = rf;
2481 chaseStack[chaseStackPointer].ff = ff;
2482 chaseStack[chaseStackPointer].rt = rt;
2483 chaseStack[chaseStackPointer].ft = ft;
2484 chaseStackPointer++;
2487 extern void ExistingAtacksCallback P((Board board, int flags, ChessMove kind,
2488 int rf, int ff, int rt, int ft,
2492 ExistingAttacksCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
2493 { // for removing pre-exsting captures from the chaseStack, to be left with newly created ones
2495 register ChaseClosure *cl = (ChaseClosure *) closure; //closure tells us the move played in the repeat loop
2497 if(board[rt][ft] == EmptySquare) return; // no capture
2498 if(rf == cl->rf && ff == cl->ff) { // attacks with same piece from new position are not considered new
2499 rf = cl->rt; ff = cl->ft; // doctor their fromSquare so they will be recognized in chaseStack
2501 // search move in chaseStack, and delete it if it occurred there (as we know now it is not a new capture)
2502 for(i=0; i<chaseStackPointer; i++) {
2503 if(chaseStack[i].rf == rf && chaseStack[i].ff == ff &&
2504 chaseStack[i].rt == rt && chaseStack[i].ft == ft ) {
2505 // move found on chaseStack, delete it by overwriting with move popped from top of chaseStack
2506 chaseStack[i] = chaseStack[--chaseStackPointer];
2512 extern void ProtectedCallback P((Board board, int flags, ChessMove kind,
2513 int rf, int ff, int rt, int ft,
2517 ProtectedCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
2518 { // for determining if a piece (given through the closure) is protected
2519 register ChaseClosure *cl = (ChaseClosure *) closure; // closure tells us where to recapture
2521 if(rt == cl->rt && ft == cl->ft) cl->recaptures++; // count legal recaptures to this square
2522 if(appData.debugMode && board[rt][ft] != EmptySquare)
2523 fprintf(debugFP, "try %c%c%c%c=%d\n", ff+AAA, rf+ONE,ft+AAA, rt+ONE, cl->recaptures);
2526 extern char moveList[MAX_MOVES][MOVE_LEN];
2529 PerpetualChase (int first, int last)
2530 { // this routine detects if the side to move in the 'first' position is perpetually chasing (when not checking)
2533 ChessSquare captured;
2535 preyStackPointer = 0; // clear stack of chased pieces
2536 for(i=first; i<last; i+=2) { // for all positions with same side to move
2537 if(appData.debugMode) fprintf(debugFP, "judge position %i\n", i);
2538 chaseStackPointer = 0; // clear stack that is going to hold possible chases
2539 // determine all captures possible after the move, and put them on chaseStack
2540 GenLegal(boards[i+1], PosFlags(i), AttacksCallback, &cl, EmptySquare);
2541 if(appData.debugMode) { int n;
2542 for(n=0; n<chaseStackPointer; n++)
2543 fprintf(debugFP, "%c%c%c%c ", chaseStack[n].ff+AAA, chaseStack[n].rf+ONE,
2544 chaseStack[n].ft+AAA, chaseStack[n].rt+ONE);
2545 fprintf(debugFP, ": all capts\n");
2547 // determine all captures possible before the move, and delete them from chaseStack
2548 cl.rf = moveList[i][1]-ONE; // prepare closure to pass move that led from i to i+1
2549 cl.ff = moveList[i][0]-AAA+BOARD_LEFT;
2550 cl.rt = moveList[i][3]-ONE;
2551 cl.ft = moveList[i][2]-AAA+BOARD_LEFT;
2552 CopyBoard(xqCheckers, nullBoard); xqCheckers[EP_STATUS] = 1; // giant kludge to make GenLegal ignore pre-existing checks
2553 GenLegal(boards[i], PosFlags(i), ExistingAttacksCallback, &cl, EmptySquare);
2554 xqCheckers[EP_STATUS] = 0; // disable the generation of quasi-legal moves again
2555 if(appData.debugMode) { int n;
2556 for(n=0; n<chaseStackPointer; n++)
2557 fprintf(debugFP, "%c%c%c%c ", chaseStack[n].ff+AAA, chaseStack[n].rf+ONE,
2558 chaseStack[n].ft+AAA, chaseStack[n].rt+ONE);
2559 fprintf(debugFP, ": new capts after %c%c%c%c\n", cl.ff+AAA, cl.rf+ONE, cl.ft+AAA, cl.rt+ONE);
2561 // chaseSack now contains all captures made possible by the move
2562 for(j=0; j<chaseStackPointer; j++) { // run through chaseStack to identify true chases
2563 int attacker = (int)boards[i+1][chaseStack[j].rf][chaseStack[j].ff];
2564 int victim = (int)boards[i+1][chaseStack[j].rt][chaseStack[j].ft];
2566 if(attacker >= (int) BlackPawn) attacker = BLACK_TO_WHITE attacker; // convert to white, as piecee type
2567 if(victim >= (int) BlackPawn) victim = BLACK_TO_WHITE victim;
2569 if((attacker == WhiteKnight || attacker == WhiteCannon) && victim == WhiteRook)
2570 continue; // C or H attack on R is always chase; leave on chaseStack
2572 if(attacker == victim) {
2573 if(LegalityTest(boards[i+1], PosFlags(i+1), chaseStack[j].rt,
2574 chaseStack[j].ft, chaseStack[j].rf, chaseStack[j].ff, NULLCHAR) == NormalMove) {
2575 // we can capture back with equal piece, so this is no chase but a sacrifice
2576 chaseStack[j] = chaseStack[--chaseStackPointer]; // delete the capture from the chaseStack
2577 j--; /* ! */ continue;
2582 // the attack is on a lower piece, or on a pinned or blocked equal one
2583 CopyBoard(xqCheckers, nullBoard); xqCheckers[EP_STATUS] = 1;
2584 CheckTest(boards[i+1], PosFlags(i+1), -1, -1, -1, -1, FALSE); // if we deliver check with our move, the checkers get marked
2585 // test if the victim is protected by a true protector. First make the capture.
2586 captured = boards[i+1][chaseStack[j].rt][chaseStack[j].ft];
2587 boards[i+1][chaseStack[j].rt][chaseStack[j].ft] = boards[i+1][chaseStack[j].rf][chaseStack[j].ff];
2588 boards[i+1][chaseStack[j].rf][chaseStack[j].ff] = EmptySquare;
2589 // Then test if the opponent can recapture
2590 cl.recaptures = 0; // prepare closure to pass recapture square and count moves to it
2591 cl.rt = chaseStack[j].rt;
2592 cl.ft = chaseStack[j].ft;
2593 if(appData.debugMode) {
2594 fprintf(debugFP, "test if we can recapture %c%c\n", cl.ft+AAA, cl.rt+ONE);
2596 xqCheckers[EP_STATUS] = 2; // causes GenLegal to ignore the checks we delivered with the move, in real life evaded before we captured
2597 GenLegal(boards[i+1], PosFlags(i+1), ProtectedCallback, &cl, EmptySquare); // try all moves
2598 xqCheckers[EP_STATUS] = 0; // disable quasi-legal moves again
2599 // unmake the capture
2600 boards[i+1][chaseStack[j].rf][chaseStack[j].ff] = boards[i+1][chaseStack[j].rt][chaseStack[j].ft];
2601 boards[i+1][chaseStack[j].rt][chaseStack[j].ft] = captured;
2602 // if a recapture was found, piece is protected, and we are not chasing it.
2603 if(cl.recaptures) { // attacked piece was defended by true protector, no chase
2604 chaseStack[j] = chaseStack[--chaseStackPointer]; // so delete from chaseStack
2608 // chaseStack now contains all moves that chased
2609 if(appData.debugMode) { int n;
2610 for(n=0; n<chaseStackPointer; n++)
2611 fprintf(debugFP, "%c%c%c%c ", chaseStack[n].ff+AAA, chaseStack[n].rf+ONE,
2612 chaseStack[n].ft+AAA, chaseStack[n].rt+ONE);
2613 fprintf(debugFP, ": chases\n");
2615 if(i == first) { // copy all people chased by first move of repeat cycle to preyStack
2616 for(j=0; j<chaseStackPointer; j++) {
2617 preyStack[j].rank = chaseStack[j].rt;
2618 preyStack[j].file = chaseStack[j].ft;
2620 preyStackPointer = chaseStackPointer;
2623 for(j=0; j<chaseStackPointer; j++) {
2624 for(k=0; k<preyStackPointer; k++) {
2625 // search the victim of each chase move on the preyStack (first occurrence)
2626 if(chaseStack[j].ft == preyStack[k].file && chaseStack[j].rt == preyStack[k].rank ) {
2627 if(k < tail) break; // piece was already identified as still being chased
2628 preyStack[preyStackPointer] = preyStack[tail]; // move chased piece to bottom part of preyStack
2629 preyStack[tail] = preyStack[k]; // by swapping
2630 preyStack[k] = preyStack[preyStackPointer];
2636 preyStackPointer = tail; // keep bottom part of preyStack, popping pieces unchased on move i.
2637 if(appData.debugMode) { int n;
2638 for(n=0; n<preyStackPointer; n++)
2639 fprintf(debugFP, "%c%c ", preyStack[n].file+AAA, preyStack[n].rank+ONE);
2640 fprintf(debugFP, "always chased upto ply %d\n", i);
2642 // now adjust the location of the chased pieces according to opponent move
2643 for(j=0; j<preyStackPointer; j++) {
2644 if(preyStack[j].rank == moveList[i+1][1]-ONE &&
2645 preyStack[j].file == moveList[i+1][0]-AAA+BOARD_LEFT) {
2646 preyStack[j].rank = moveList[i+1][3]-ONE;
2647 preyStack[j].file = moveList[i+1][2]-AAA+BOARD_LEFT;
2652 return preyStackPointer ? 256*(preyStack[preyStackPointer].file - BOARD_LEFT + AAA) + (preyStack[preyStackPointer].rank + ONE)
2653 : 0; // if any piece was left on preyStack, it has been perpetually chased,and we return the