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
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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];
126 PieceToChar (ChessSquare p)
129 if((int)p < 0 || (int)p >= (int)EmptySquare) return('x'); /* [HGM] for safety */
130 c = pieceToChar[(int) p];
131 if(c & 128) c = c & 63 | 64;
136 PieceSuffix (ChessSquare p)
139 if((int)p < 0 || (int)p >= (int)EmptySquare) return 0; /* [HGM] for safety */
140 c = pieceToChar[(int) p];
141 if(c < 128) return 0;
142 return SUFFIXES[c - 128 >> 6];
146 PieceToNumber (ChessSquare p) /* [HGM] holdings: count piece type, ignoring non-participating piece types */
149 ChessSquare start = (int)p >= (int)BlackPawn ? BlackPawn : WhitePawn;
151 while(start++ != p) if(pieceToChar[start-1] != '.' && pieceToChar[start-1] != '+') i++;
159 if(c == '.') return EmptySquare;
160 for(i=0; i< (int) EmptySquare; i++)
161 if(pieceNickName[i] == c) return (ChessSquare) i;
162 for(i=0; i< (int) EmptySquare; i++)
163 if(pieceToChar[i] == c) return (ChessSquare) i;
168 CopyBoard (Board to, Board from)
172 for (i = 0; i < BOARD_HEIGHT; i++)
173 for (j = 0; j < BOARD_WIDTH; j++)
174 to[i][j] = from[i][j];
175 for (j = 0; j < BOARD_FILES; j++) // [HGM] gamestate: copy castling rights and ep status
176 to[VIRGIN][j] = from[VIRGIN][j],
177 to[CASTLING][j] = from[CASTLING][j];
178 to[HOLDINGS_SET] = 0; // flag used in ICS play
182 CompareBoards (Board board1, Board board2)
186 for (i = 0; i < BOARD_HEIGHT; i++)
187 for (j = 0; j < BOARD_WIDTH; j++) {
188 if (board1[i][j] != board2[i][j])
194 char defaultName[] = "PNBRQ......................................K" // white
195 "pnbrq......................................k"; // black
196 char shogiName[] = "PNBRLS...G.++++++..........................K" // white
197 "pnbrls...g.++++++..........................k"; // black
198 char xqName[] = "PH.R.AE..K.C................................" // white
199 "ph.r.ae..k.c................................"; // black
202 CollectPieceDescriptors ()
203 { // make a line of piece descriptions for use in the PGN Piece tag:
204 // dump all engine defined pieces, and pieces with non-standard names,
205 // but suppress black pieces that are the same as their white counterpart
207 static char buf[MSG_SIZ];
208 char *m, c, d, *pieceName = defaultName;
211 if(!pieceDefs) return "";
212 if(gameInfo.variant == VariantChu) return ""; // for now don't do this for Chu Shogi
213 if(gameInfo.variant == VariantShogi) pieceName = shogiName;
214 if(gameInfo.variant == VariantXiangqi) pieceName = xqName;
215 for(p=WhitePawn; p<EmptySquare; p++) {
216 if((c = pieceToChar[p]) == '.' || c == '~') continue; // does not participate
217 m = pieceDesc[p]; d = (c == '+' ? pieceToChar[DEMOTED(p)] : c);
218 if(p >= BlackPawn && pieceToChar[BLACK_TO_WHITE p] == toupper(c)
219 && (c != '+' || pieceToChar[DEMOTED(BLACK_TO_WHITE p)] == d)) {// black member of normal pair
220 char *wm = pieceDesc[BLACK_TO_WHITE p];
221 if(!m && !wm || m && wm && !strcmp(wm, m)) continue; // moves as a white piece
222 } else // white or unpaired black
223 if((p < BlackPawn || CharToPiece(toupper(d)) != EmptySquare) && // white or lone black
224 !pieceDesc[p] /*&& pieceName[p] == c*/) continue; // orthodox piece known by its usual name
225 // TODO: listing pieces because of unusual name can only be done if we have accurate Betza of all defaults
226 if(!m) m = defaultDesc[p];
228 snprintf(buf+len, MSG_SIZ-len, "%s%s%c:%s", len ? ";" : "", c == '+' ? "+" : "", d, m);
233 // [HGM] gen: configurable move generation from Betza notation sent by engine.
234 // Some notes about two-leg moves: GenPseudoLegal() works in two modes, depending on whether a 'kill-
235 // square has been set: without one is generates all moves, and a global int legNr flags in bits 0 and 1
236 // if the move has 1 or 2 legs. Only the marking of squares makes use of this info, by only marking
237 // target squares of leg 1 (rejecting null move). A dummy move with MoveType 'FirstLeg' to the relay square
238 // is generated, so a cyan marker can be put there, and other functions can ignore such a move. When the
239 // user selects this square, it becomes the kill-square. Once a kill-square is set, only 2-leg moves are
240 // generated that use that square as relay, plus 1-leg moves, so the 1-leg move that goes to the kill-square
241 // can be marked during 2nd-leg entry to terminate the move there. For judging the pseudo-legality of the
242 // 2nd leg, the from-square has to be considered empty, although the moving piece is still on it.
246 // alphabet "abcdefghijklmnopqrstuvwxyz"
247 char symmetry[] = "FBNW.FFW.NKN.NW.QR....W..N";
248 char xStep[] = "2110.130.102.10.00....0..2";
249 char yStep[] = "2132.133.313.20.11....1..3";
250 char dirType[] = "01000104000200000260050000";
251 char upgrade[] = "AFCD.BGH.JQL.NO.KW....R..Z";
252 char rotate[] = "DRCA.WHG.JKL.NO.QB....F..Z";
254 // 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 "
255 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 };
256 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 };
257 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 };
258 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 };
260 int rot[][4] = { // rotation matrices for each direction
272 OK (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR cl)
278 MovesFromString (Board board, int flags, int f, int r, int tx, int ty, int angle, char *desc, MoveCallback cb, VOIDSTAR cl)
280 char buf[80], *p = desc, *atom = NULL;
281 int mine, his, dir, bit, occup, i, ep, promoRank = -1;
282 ChessMove promo= NormalMove; ChessSquare pc = board[r][f];
283 if(pc == DarkSquare) return; // this is not a piece, but a 'hole' in the board
284 if(flags & F_WHITE_ON_MOVE) his = 2, mine = 1; else his = 1, mine = 2;
285 if(pc == WhitePawn || pc == WhiteLance) promo = WhitePromotion, promoRank = BOARD_HEIGHT-1; else
286 if(pc == BlackPawn || pc == BlackLance) promo = BlackPromotion, promoRank = 0;
287 while(*p) { // more moves to go
288 int expo = 1, dx, dy, x, y, mode, dirSet, ds2=0, retry=0, initial=0, jump=1, skip = 0, all = 0;
290 while(*p == 'i') initial++, desc = ++p;
291 while(islower(*p)) p++; // skip prefixes
292 if(!isupper(*p)) return; // syntax error: no atom
293 dx = xStep[*p-'A'] - '0';// step vector of atom
294 dy = yStep[*p-'A'] - '0';
295 dirSet = 0; // build direction set based on atom symmetry
296 switch(symmetry[*p-'A']) {
297 case 'B': expo = 0; // bishop, slide
298 case 'F': all = 0xAA; // diagonal atom (degenerate 4-fold)
299 if(tx >= 0) goto king; // continuation legs specified in K/Q system!
300 while(islower(*desc) && (i = dirType[*desc-'a']) != '0') {
301 int b = dirs1[*desc-'a']; // use wide version
302 if( islower(desc[1]) &&
303 ((i | dirType[desc[1]-'a']) & 3) == 3) { // combinable (perpendicular dim)
304 b = dirs1[*desc-'a'] & dirs1[desc[1]-'a']; // intersect wide & perp wide
309 dirSet &= 0xAA; if(!dirSet) dirSet = 0xAA;
311 case 'R': expo = 0; // rook, slide
312 case 'W': all = 0x55; // orthogonal atom (non-deg 4-fold)
313 if(tx >= 0) goto king; // continuation legs specified in K/Q system!
314 while(islower(*desc) && (dirType[*desc-'a'] & ~4) != '0') dirSet |= dirs2[*desc++-'a'];
315 dirSet &= 0x55; if(!dirSet) dirSet = 0x55;
316 dirSet = (dirSet << angle | dirSet >> 8-angle) & 255; // re-orient direction system
318 case 'N': all = 0xFF; // oblique atom (degenerate 8-fold)
319 if(tx >= 0) goto king; // continuation legs specified in K/Q system!
320 if(*desc == 'h') { // chiral direction sets 'hr' and 'hl'
321 dirSet = (desc[1] == 'r' ? 0x55 : 0xAA); desc += 2;
323 while(islower(*desc) && (i = dirType[*desc-'a']) != '0') {
324 int b = dirs2[*desc-'a']; // when alone, use narrow version
325 if(desc[1] == 'h') b = dirs1[*desc-'a'], desc += 2; // dirs1 is wide version
326 else if(*desc == desc[1] || islower(desc[1]) && i < '4'
327 && ((i | dirType[desc[1]-'a']) & 3) == 3) { // combinable (perpendicular dim or same)
328 b = dirs1[*desc-'a'] & dirs2[desc[1]-'a']; // intersect wide & perp narrow
333 if(!dirSet) dirSet = 0xFF;
335 case 'Q': expo = 0; // queen, slide
336 case 'K': all = 0xFF; // non-deg (pseudo) 8-fold
338 while(islower(*desc) && (i = dirType[*desc-'a']) != '0') {
339 int b = dirs4[*desc-'a']; // when alone, use narrow version
340 if(desc[1] == *desc) desc++; // doubling forces alone
341 else if(islower(desc[1]) && i < '4'
342 && ((i | dirType[desc[1]-'a']) & 3) == 3) { // combinable (perpendicular dim or same)
343 b = dirs3[*desc-'a'] & dirs3[desc[1]-'a']; // intersect wide & perp wide
348 if(!dirSet) dirSet = (tx < 0 ? 0xFF // default is all directions, but in continuation leg
349 : all == 0xFF ? 0xEF : 0x45); // omits backward, and for 4-fold atoms also diags
350 dirSet = (dirSet << angle | dirSet >> 8-angle) & 255; // re-orient direction system
351 ds2 = dirSet & 0xAA; // extract diagonal directions
352 if(dirSet &= 0x55) // start with orthogonal moves, if present
353 retry = 1, dx = 0; // and schedule the diagonal moves for later
354 else dx = dy, dirSet = ds2; // if no orthogonal directions, do diagonal immediately
355 break; // should not have direction indicators
356 default: return; // syntax error: invalid atom
358 if(mine == 2 && tx < 0) dirSet = dirSet >> 4 | dirSet << 4 & 255; // invert black moves
359 mode = 0; // build mode mask
360 if(*desc == 'm') mode |= 4, desc++; // move to empty
361 if(*desc == 'c') mode |= his, desc++; // capture foe
362 if(*desc == 'd') mode |= mine, desc++; // destroy (capture friend)
363 if(*desc == 'e') mode |= 8, desc++; // e.p. capture last mover
364 if(*desc == 't') mode |= 16, desc++; // exclude enemies as hop platform ('test')
365 if(*desc == 'p') mode |= 32, desc++; // hop over occupied
366 if(*desc == 'g') mode |= 64, desc++; // hop and toggle range
367 if(*desc == 'o') mode |= 128, desc++; // wrap around cylinder board
368 if(*desc == 'y') mode |= 512, desc++; // toggle range on empty square
369 if(*desc == 'n') jump = 0, desc++; // non-jumping
370 while(*desc == 'j') jump++, desc++; // must jump (on B,R,Q: skip first square)
371 if(*desc == 'a') cont = ++desc; // move again after doing what preceded it
372 if(isdigit(*++p)) expo = atoi(p++); // read exponent
373 if(expo > 9) p++; // allow double-digit
374 desc = p; // this is start of next move
375 if(initial == 2) { if(board[r][f] != initialPosition[r-2*his+3][f]) continue; } else
376 if(initial && (board[r][f] != initialPosition[r][f] ||
377 r == 0 && board[TOUCHED_W] & 1<<f ||
378 r == BOARD_HEIGHT-1 && board[TOUCHED_B] & 1<<f ) ) continue;
379 if(expo > 1 && dx == 0 && dy == 0) { // castling indicated by O + number
380 mode |= 1024; dy = 1;
383 if(!(mode & 15)) mode |= his + 4; // no mode spec, use default = mc
385 strncpy(buf, cont, 80); cont = buf; // copy next leg(s), so we can modify
386 atom = buf; while(islower(*atom)) atom++; // skip to atom
387 if(mode & 32) mode ^= 256 + 32; // in non-final legs 'p' means 'pass through'
388 if(mode & 64 + 512) {
389 mode |= 256; // and 'g' too, but converts leaper <-> slider
390 if(mode & 512) mode ^= 0x304; // and 'y' is m-like 'g'
391 *atom = upgrade[*atom-'A']; // replace atom, BRQ <-> FWK
392 atom[1] = atom[2] = '\0'; // make sure any old range is stripped off
393 if(expo == 1) atom[1] = '0'; // turn other leapers into riders
395 if(!(mode & 0x30F)) mode |= 4; // and default of this leg = m
397 if(dy == 1) skip = jump - 1, jump = 1; // on W & F atoms 'j' = skip first square
399 for(dir=0, bit=1; dir<8; dir++, bit += bit) { // loop over directions
400 int i = expo, j = skip, hop = mode, vx, vy, loop = 0;
401 if(!(bit & dirSet)) continue; // does not move in this direction
402 if(dy != 1 || mode & 1024) j = 0; //
403 vx = dx*rot[dir][0] + dy*rot[dir][1]; // rotate step vector
404 vy = dx*rot[dir][2] + dy*rot[dir][3];
405 if(tx < 0) x = f, y = r; // start square
406 else x = tx, y = ty; // from previous to-square if continuation
408 x += vx; y += vy; // step to next square
409 if(y < 0 || y >= BOARD_HEIGHT) break; // vertically off-board: always done
410 if(x < BOARD_LEFT) { if(mode & 128) x += BOARD_RGHT - BOARD_LEFT, loop++; else break; }
411 if(x >= BOARD_RGHT) { if(mode & 128) x -= BOARD_RGHT - BOARD_LEFT, loop++; else break; }
412 if(j) { j--; continue; } // skip irrespective of occupation
413 if(board[y][x] == DarkSquare) break; // black squares are supposed to be off board
414 if(!jump && board[y - vy + vy/2][x - vx + vx/2] != EmptySquare) break; // blocked
415 if(jump > 1 && board[y - vy + vy/2][x - vx + vx/2] == EmptySquare) break; // no hop
416 if(x == f && y == r && !loop) occup = 4; else // start square counts as empty (if not around cylinder!)
417 if(board[y][x] < BlackPawn) occup = 0x101; else
418 if(board[y][x] < EmptySquare) occup = 0x102; else
420 if(cont) { // non-final leg
421 if(mode&16 && his&occup) occup &= 3;// suppress hopping foe in t-mode
422 if(occup & mode) { // valid intermediate square, do continuation
423 char origAtom = *atom;
424 if(!(bit & all)) *atom = rotate[*atom - 'A']; // orth-diag interconversion to make direction valid
425 if(occup & mode & 0x104) // no side effects, merge legs to one move
426 MovesFromString(board, flags, f, r, x, y, dir, cont, cb, cl);
427 if(occup & mode & 3 && (killX < 0 || killX == x && killY == y)) { // destructive first leg
429 MovesFromString(board, flags, f, r, x, y, dir, cont, &OK, &cnt); // count possible continuations
430 if(cnt) { // and if there are
431 if(killX < 0) cb(board, flags, FirstLeg, r, f, y, x, cl); // then generate their first leg
433 MovesFromString(board, flags, f, r, x, y, dir, cont, cb, cl);
437 *atom = origAtom; // undo any interconversion
439 if(occup != 4) break; // occupied squares always terminate the leg
442 if(hop & 32+64) { if(occup != 4) { if(hop & 64 && i != 1) i = 2; hop &= 31; } continue; } // hopper
444 if(mode & 8 && occup == 4 && board[EP_FILE] == x && (y == (ep & 127) || y - vy == ep - 128)) { // to e.p. square (or 2nd e.p. square)
445 cb(board, flags, mine == 1 ? WhiteCapturesEnPassant : BlackCapturesEnPassant, r, f, y, x, cl);
447 if(mode & 1024) { // castling
448 i = 2; // kludge to elongate move indefinitely
449 if(occup == 4) continue; // skip empty squares
450 if((x == BOARD_LEFT + skip || x > BOARD_LEFT + skip && vx < 0 && board[y][x-1-skip] == DarkSquare)
451 && board[y][x] == initialPosition[y][x]) { // reached initial corner piece
452 if(pc != WhiteKing && pc != BlackKing) { // non-royal castling (to be entered as two-leg move via 'Rook')
453 if(killX < 0) cb(board, flags, FirstLeg, r, f, y, x, cl); if(killX < f)
454 legNr <<= 1, cb(board, flags, NormalMove, r, f, y, f - expo, cl), legNr >>= 1;
456 cb(board, flags, mine == 1 ? WhiteQueenSideCastle : BlackQueenSideCastle, r, f, y, f - expo, cl);
458 if((x == BOARD_RGHT-1-skip || x < BOARD_RGHT-1-skip && vx > 0 && board[y][x+1+skip] == DarkSquare)
459 && board[y][x] == initialPosition[y][x]) {
460 if(pc != WhiteKing && pc != BlackKing) {
461 if(killX < 0) cb(board, flags, FirstLeg, r, f, y, x, cl); if(killX > f)
462 legNr <<= 1, cb(board, flags, NormalMove, r, f, y, f + expo, cl), legNr >>= 1;
464 cb(board, flags, mine == 1 ? WhiteKingSideCastle : BlackKingSideCastle, r, f, y, f + expo, cl);
468 if(mode & 16 && (board[y][x] == WhiteKing || board[y][x] == BlackKing)) break; // tame piece, cannot capture royal
469 if(occup & mode) cb(board, flags, y == promoRank ? promo : NormalMove, r, f, y, x, cl); // allowed, generate
470 if(occup != 4) break; // not valid transit square
473 dx = dy; dirSet = ds2; // prepare for diagonal moves of K,Q
474 } while(retry-- && ds2); // and start doing them
475 if(tx >= 0) break; // don't do other atoms in continuation legs
479 // [HGM] move generation now based on hierarchy of subroutines for rays and combinations of rays
482 SlideForward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
487 if (rt >= BOARD_HEIGHT) break;
488 if (SameColor(board[rf][ff], board[rt][ft])) break;
489 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
490 if (board[rt][ft] != EmptySquare) break;
495 SlideBackward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
501 if (SameColor(board[rf][ff], board[rt][ft])) break;
502 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
503 if (board[rt][ft] != EmptySquare) break;
508 SlideVertical (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
510 SlideForward(board, flags, rf, ff, callback, closure);
511 SlideBackward(board, flags, rf, ff, callback, closure);
515 SlideSideways (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
517 int i, s, rt = rf, ft;
518 for(s = -1; s <= 1; s+= 2) {
521 if (ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
522 if (SameColor(board[rf][ff], board[rt][ft])) break;
523 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
524 if (board[rt][ft] != EmptySquare) break;
530 SlideDiagForward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
533 for(s = -1; s <= 1; s+= 2) {
537 if (rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
538 if (SameColor(board[rf][ff], board[rt][ft])) break;
539 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
540 if (board[rt][ft] != EmptySquare) break;
546 SlideDiagBackward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
549 for(s = -1; s <= 1; s+= 2) {
553 if (rt < 0 || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
554 if (SameColor(board[rf][ff], board[rt][ft])) break;
555 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
556 if (board[rt][ft] != EmptySquare) break;
562 Rook (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
564 SlideVertical(board, flags, rf, ff, callback, closure);
565 SlideSideways(board, flags, rf, ff, callback, closure);
569 Bishop (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
571 SlideDiagForward(board, flags, rf, ff, callback, closure);
572 SlideDiagBackward(board, flags, rf, ff, callback, closure);
576 Sting (Board board, int flags, int rf, int ff, int dy, int dx, MoveCallback callback, VOIDSTAR closure)
577 { // Lion-like move of Horned Falcon and Souring Eagle
578 int ft = ff + dx, rt = rf + dy;
579 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) return;
581 if (!SameColor(board[rf][ff], board[rt][ft]))
582 callback(board, flags, board[rt][ft] != EmptySquare ? FirstLeg : NormalMove, rf, ff, rt, ft, closure);
585 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) return;
587 if (!SameColor(board[rf][ff], board[rt][ft]))
588 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
589 if (!SameColor(board[rf][ff], board[rf+dy][ff+dx]))
590 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
595 StepForward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
597 int ft = ff, rt = rf + 1;
598 if (rt >= BOARD_HEIGHT) return;
599 if (SameColor(board[rf][ff], board[rt][ft])) return;
600 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
604 StepBackward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
606 int ft = ff, rt = rf - 1;
608 if (SameColor(board[rf][ff], board[rt][ft])) return;
609 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
613 StepSideways (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
617 if (!(rt >= BOARD_HEIGHT || ft >= BOARD_RGHT) && !SameColor(board[rf][ff], board[rt][ft]))
618 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
620 if (!(rt >= BOARD_HEIGHT || ft < BOARD_LEFT) && !SameColor(board[rf][ff], board[rt][ft]))
621 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
625 StepDiagForward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
628 if (rt >= BOARD_HEIGHT) return;
630 if (!(rt >= BOARD_HEIGHT || ft >= BOARD_RGHT) && !SameColor(board[rf][ff], board[rt][ft]))
631 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
633 if (!(rt >= BOARD_HEIGHT || ft < BOARD_LEFT) && !SameColor(board[rf][ff], board[rt][ft]))
634 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
638 StepDiagBackward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
643 if (!(rt < 0 || ft >= BOARD_RGHT) && !SameColor(board[rf][ff], board[rt][ft]))
644 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
646 if (!(rt < 0 || ft < BOARD_LEFT) && !SameColor(board[rf][ff], board[rt][ft]))
647 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
651 StepVertical (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
653 StepForward(board, flags, rf, ff, callback, closure);
654 StepBackward(board, flags, rf, ff, callback, closure);
658 Ferz (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
660 StepDiagForward(board, flags, rf, ff, callback, closure);
661 StepDiagBackward(board, flags, rf, ff, callback, closure);
665 Wazir (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
667 StepVertical(board, flags, rf, ff, callback, closure);
668 StepSideways(board, flags, rf, ff, callback, closure);
672 Knight (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
675 for (i = -1; i <= 1; i += 2)
676 for (j = -1; j <= 1; j += 2)
677 for (s = 1; s <= 2; s++) {
680 if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
681 && ( gameInfo.variant != VariantXiangqi || board[rf+i*(s-1)][ff+j*(2-s)] == EmptySquare)
682 && !SameColor(board[rf][ff], board[rt][ft]))
683 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
687 /* Call callback once for each pseudo-legal move in the given
688 position, except castling moves. A move is pseudo-legal if it is
689 legal, or if it would be legal except that it leaves the king in
690 check. In the arguments, epfile is EP_NONE if the previous move
691 was not a double pawn push, or the file 0..7 if it was, or
692 EP_UNKNOWN if we don't know and want to allow all e.p. captures.
693 Promotion moves generated are to Queen only.
696 GenPseudoLegal (Board board, int flags, MoveCallback callback, VOIDSTAR closure, ChessSquare filter)
697 // speed: only do moves with this piece type
700 int i, j, d, s, fs, rs, rt, ft, m;
701 int epfile = (signed char)board[EP_STATUS]; // [HGM] gamestate: extract ep status from board
702 int promoRank = gameInfo.variant == VariantMakruk || gameInfo.variant == VariantGrand || gameInfo.variant == VariantChuChess ? 3 : 1;
704 for (rf = 0; rf < BOARD_HEIGHT; rf++)
705 for (ff = BOARD_LEFT; ff < BOARD_RGHT; ff++) {
708 if(board[rf][ff] == EmptySquare) continue;
709 if ((flags & F_WHITE_ON_MOVE) != (board[rf][ff] < BlackPawn)) continue; // [HGM] speed: wrong color
710 m = 0; piece = board[rf][ff];
711 if(PieceToChar(piece) == '~')
712 piece = (ChessSquare) ( DEMOTED(piece) );
713 if(filter != EmptySquare && piece != filter) continue;
714 if(pieceDefs && pieceDesc[piece]) { // [HGM] gen: use engine-defined moves
715 MovesFromString(board, flags, ff, rf, -1, -1, 0, pieceDesc[piece], callback, closure);
718 if(IS_SHOGI(gameInfo.variant))
719 piece = (ChessSquare) ( SHOGI piece );
721 switch ((int)piece) {
722 /* case EmptySquare: [HGM] this is nonsense, and conflicts with Shogi cases */
724 /* can't happen ([HGM] except for faries...) */
728 if(gameInfo.variant == VariantXiangqi) {
729 /* [HGM] capture and move straight ahead in Xiangqi */
730 if (rf < BOARD_HEIGHT-1 &&
731 !SameColor(board[rf][ff], board[rf + 1][ff]) ) {
732 callback(board, flags, NormalMove,
733 rf, ff, rf + 1, ff, closure);
735 /* and move sideways when across the river */
736 for (s = -1; s <= 1; s += 2) {
737 if (rf >= BOARD_HEIGHT>>1 &&
738 ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
739 !WhitePiece(board[rf][ff+s]) ) {
740 callback(board, flags, NormalMove,
741 rf, ff, rf, ff+s, closure);
746 if (rf < BOARD_HEIGHT-1 && board[rf + 1][ff] == EmptySquare) {
747 callback(board, flags,
748 rf >= BOARD_HEIGHT-1-promoRank ? WhitePromotion : NormalMove,
749 rf, ff, rf + 1, ff, closure);
751 if (rf <= (BOARD_HEIGHT>>1)-3 && board[rf+1][ff] == EmptySquare && // [HGM] grand: also on 3rd rank on 10-board
752 gameInfo.variant != VariantShatranj && /* [HGM] */
753 gameInfo.variant != VariantCourier && /* [HGM] */
754 board[rf+2][ff] == EmptySquare ) {
755 callback(board, flags, NormalMove,
756 rf, ff, rf+2, ff, closure);
758 for (s = -1; s <= 1; s += 2) {
759 if (rf < BOARD_HEIGHT-1 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
760 ((flags & F_KRIEGSPIEL_CAPTURE) ||
761 BlackPiece(board[rf + 1][ff + s]))) {
762 callback(board, flags,
763 rf >= BOARD_HEIGHT-1-promoRank ? WhitePromotion : NormalMove,
764 rf, ff, rf + 1, ff + s, closure);
766 if (rf >= BOARD_HEIGHT+1>>1) {// [HGM] grand: 4th & 5th rank on 10-board
767 if (ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
768 (epfile == ff + s || epfile == EP_UNKNOWN) && rf < BOARD_HEIGHT-3 &&
769 board[rf][ff + s] == BlackPawn &&
770 board[rf+1][ff + s] == EmptySquare) {
771 callback(board, flags, WhiteCapturesEnPassant,
772 rf, ff, rf+1, ff + s, closure);
779 if(gameInfo.variant == VariantXiangqi) {
780 /* [HGM] capture straight ahead in Xiangqi */
781 if (rf > 0 && !SameColor(board[rf][ff], board[rf - 1][ff]) ) {
782 callback(board, flags, NormalMove,
783 rf, ff, rf - 1, ff, closure);
785 /* and move sideways when across the river */
786 for (s = -1; s <= 1; s += 2) {
787 if (rf < BOARD_HEIGHT>>1 &&
788 ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
789 !BlackPiece(board[rf][ff+s]) ) {
790 callback(board, flags, NormalMove,
791 rf, ff, rf, ff+s, closure);
796 if (rf > 0 && board[rf - 1][ff] == EmptySquare) {
797 callback(board, flags,
798 rf <= promoRank ? BlackPromotion : NormalMove,
799 rf, ff, rf - 1, ff, closure);
801 if (rf >= (BOARD_HEIGHT+1>>1)+2 && board[rf-1][ff] == EmptySquare && // [HGM] grand
802 gameInfo.variant != VariantShatranj && /* [HGM] */
803 gameInfo.variant != VariantCourier && /* [HGM] */
804 board[rf-2][ff] == EmptySquare) {
805 callback(board, flags, NormalMove,
806 rf, ff, rf-2, ff, closure);
808 for (s = -1; s <= 1; s += 2) {
809 if (rf > 0 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
810 ((flags & F_KRIEGSPIEL_CAPTURE) ||
811 WhitePiece(board[rf - 1][ff + s]))) {
812 callback(board, flags,
813 rf <= promoRank ? BlackPromotion : NormalMove,
814 rf, ff, rf - 1, ff + s, closure);
816 if (rf < BOARD_HEIGHT>>1) {
817 if (ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
818 (epfile == ff + s || epfile == EP_UNKNOWN) && rf > 2 &&
819 board[rf][ff + s] == WhitePawn &&
820 board[rf-1][ff + s] == EmptySquare) {
821 callback(board, flags, BlackCapturesEnPassant,
822 rf, ff, rf-1, ff + s, closure);
832 for (i = -1; i <= 1; i += 2)
833 for (j = -1; j <= 1; j += 2)
834 for (s = 1; s <= 2; s++) {
837 if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
838 && ( gameInfo.variant != VariantXiangqi || board[rf+i*(s-1)][ff+j*(2-s)] == EmptySquare)
839 && !SameColor(board[rf][ff], board[rt][ft]))
840 callback(board, flags, NormalMove,
841 rf, ff, rt, ft, closure);
845 case SHOGI WhiteKnight:
846 for (s = -1; s <= 1; s += 2) {
847 if (rf < BOARD_HEIGHT-2 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
848 !SameColor(board[rf][ff], board[rf + 2][ff + s])) {
849 callback(board, flags, NormalMove,
850 rf, ff, rf + 2, ff + s, closure);
855 case SHOGI BlackKnight:
856 for (s = -1; s <= 1; s += 2) {
857 if (rf > 1 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
858 !SameColor(board[rf][ff], board[rf - 2][ff + s])) {
859 callback(board, flags, NormalMove,
860 rf, ff, rf - 2, ff + s, closure);
867 for (d = 0; d <= 1; d++)
868 for (s = -1; s <= 1; s += 2) {
871 rt = rf + (i * s) * d;
872 ft = ff + (i * s) * (1 - d);
873 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
874 if (m == 0 && board[rt][ft] == EmptySquare)
875 callback(board, flags, NormalMove,
876 rf, ff, rt, ft, closure);
877 if (m == 1 && board[rt][ft] != EmptySquare &&
878 !SameColor(board[rf][ff], board[rt][ft]) )
879 callback(board, flags, NormalMove,
880 rf, ff, rt, ft, closure);
881 if (board[rt][ft] != EmptySquare && m++) break;
886 /* Gold General (and all its promoted versions) . First do the */
887 /* diagonal forward steps, then proceed as normal Wazir */
888 case SHOGI (PROMO WhitePawn):
889 if(gameInfo.variant == VariantShogi) goto WhiteGold;
890 case SHOGI (PROMO BlackPawn):
891 if(gameInfo.variant == VariantShogi) goto BlackGold;
892 SlideVertical(board, flags, rf, ff, callback, closure);
895 case SHOGI (PROMO WhiteKnight):
896 if(gameInfo.variant == VariantShogi) goto WhiteGold;
897 case SHOGI BlackDrunk:
898 case SHOGI BlackAlfil:
899 Ferz(board, flags, rf, ff, callback, closure);
900 StepSideways(board, flags, rf, ff, callback, closure);
901 StepBackward(board, flags, rf, ff, callback, closure);
904 case SHOGI (PROMO BlackKnight):
905 if(gameInfo.variant == VariantShogi) goto BlackGold;
906 case SHOGI WhiteDrunk:
907 case SHOGI WhiteAlfil:
908 Ferz(board, flags, rf, ff, callback, closure);
909 StepSideways(board, flags, rf, ff, callback, closure);
910 StepForward(board, flags, rf, ff, callback, closure);
914 case SHOGI WhiteStag:
915 case SHOGI BlackStag:
916 if(gameInfo.variant == VariantShogi) goto BlackGold;
917 SlideVertical(board, flags, rf, ff, callback, closure);
918 Ferz(board, flags, rf, ff, callback, closure);
919 StepSideways(board, flags, rf, ff, callback, closure);
922 case SHOGI (PROMO WhiteQueen):
923 case SHOGI WhiteTokin:
924 case SHOGI WhiteWazir:
926 StepDiagForward(board, flags, rf, ff, callback, closure);
927 Wazir(board, flags, rf, ff, callback, closure);
930 case SHOGI (PROMO BlackQueen):
931 case SHOGI BlackTokin:
932 case SHOGI BlackWazir:
934 StepDiagBackward(board, flags, rf, ff, callback, closure);
935 Wazir(board, flags, rf, ff, callback, closure);
940 Wazir(board, flags, rf, ff, callback, closure);
943 case SHOGI WhiteMarshall:
944 case SHOGI BlackMarshall:
945 Ferz(board, flags, rf, ff, callback, closure);
946 for (d = 0; d <= 1; d++)
947 for (s = -2; s <= 2; s += 4) {
949 ft = ff + s * (1 - d);
950 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) continue;
951 if (!SameColor(board[rf][ff], board[rt][ft]) )
952 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
956 case SHOGI WhiteAngel:
957 case SHOGI BlackAngel:
958 Wazir(board, flags, rf, ff, callback, closure);
962 /* [HGM] support Shatranj pieces */
963 for (rs = -1; rs <= 1; rs += 2)
964 for (fs = -1; fs <= 1; fs += 2) {
967 if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
968 && ( gameInfo.variant != VariantXiangqi ||
969 board[rf+rs][ff+fs] == EmptySquare && (2*rf < BOARD_HEIGHT) == (2*rt < BOARD_HEIGHT) )
971 && !SameColor(board[rf][ff], board[rt][ft]))
972 callback(board, flags, NormalMove,
973 rf, ff, rt, ft, closure);
974 if(gameInfo.variant == VariantShatranj || gameInfo.variant == VariantCourier ||
975 gameInfo.variant == VariantChu || gameInfo.variant == VariantXiangqi) continue; // classical Alfil
976 rt = rf + rs; // in unknown variant we assume Modern Elephant, which can also do one step
978 if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
979 && !SameColor(board[rf][ff], board[rt][ft]))
980 callback(board, flags, NormalMove,
981 rf, ff, rt, ft, closure);
983 if(gameInfo.variant == VariantSpartan)
984 for(fs = -1; fs <= 1; fs += 2) {
986 if (!(ft < BOARD_LEFT || ft >= BOARD_RGHT) && board[rf][ft] == EmptySquare)
987 callback(board, flags, NormalMove, rf, ff, rf, ft, closure);
991 /* Make Dragon-Horse also do Dababba moves outside Shogi, for better disambiguation in variant Fairy */
994 if(gameInfo.variant == VariantChuChess) goto DragonHorse;
995 for (d = 0; d <= 1; d++) // Dababba moves that Rook cannot do
996 for (s = -2; s <= 2; s += 4) {
998 ft = ff + s * (1 - d);
999 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) continue;
1000 if (SameColor(board[rf][ff], board[rt][ft])) continue;
1001 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
1004 /* Shogi Dragon Horse has to continue with Wazir after Bishop */
1005 case SHOGI WhiteCardinal:
1006 case SHOGI BlackCardinal:
1007 case SHOGI WhitePCardinal:
1008 case SHOGI BlackPCardinal:
1010 Bishop(board, flags, rf, ff, callback, closure);
1011 Wazir(board, flags, rf, ff, callback, closure);
1014 /* Capablanca Archbishop continues as Knight */
1017 Knight(board, flags, rf, ff, callback, closure);
1019 /* Shogi Bishops are ordinary Bishops */
1020 case SHOGI WhiteBishop:
1021 case SHOGI BlackBishop:
1022 case SHOGI WhitePBishop:
1023 case SHOGI BlackPBishop:
1026 Bishop(board, flags, rf, ff, callback, closure);
1029 /* Shogi Lance is unlike anything, and asymmetric at that */
1030 case SHOGI WhiteQueen:
1031 if(gameInfo.variant == VariantChu) goto doQueen;
1035 if (rt >= BOARD_HEIGHT) break;
1036 if (SameColor(board[rf][ff], board[rt][ft])) break;
1037 callback(board, flags, NormalMove,
1038 rf, ff, rt, ft, closure);
1039 if (board[rt][ft] != EmptySquare) break;
1043 case SHOGI BlackQueen:
1044 if(gameInfo.variant == VariantChu) goto doQueen;
1049 if (SameColor(board[rf][ff], board[rt][ft])) break;
1050 callback(board, flags, NormalMove,
1051 rf, ff, rt, ft, closure);
1052 if (board[rt][ft] != EmptySquare) break;
1056 /* Make Dragon-King Dababba & Rook-like outside Shogi, for better disambiguation in variant Fairy */
1059 if(gameInfo.variant == VariantChuChess) goto DragonKing;
1060 for (d = 0; d <= 1; d++) // Dababba moves that Rook cannot do
1061 for (s = -2; s <= 2; s += 4) {
1063 ft = ff + s * (1 - d);
1064 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) continue;
1065 if (board[rf+rt>>1][ff+ft>>1] == EmptySquare && gameInfo.variant != VariantSpartan) continue;
1066 if (SameColor(board[rf][ff], board[rt][ft])) continue;
1067 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
1069 if(gameInfo.variant == VariantSpartan) // in Spartan Chess restrict range to modern Dababba
1070 Wazir(board, flags, rf, ff, callback, closure);
1072 Rook(board, flags, rf, ff, callback, closure);
1075 /* Shogi Dragon King has to continue as Ferz after Rook moves */
1076 case SHOGI WhiteDragon:
1077 case SHOGI BlackDragon:
1078 case SHOGI WhitePDragon:
1079 case SHOGI BlackPDragon:
1081 Rook(board, flags, rf, ff, callback, closure);
1082 Ferz(board, flags, rf, ff, callback, closure);
1086 /* Capablanca Chancellor sets flag to continue as Knight */
1089 Rook(board, flags, rf, ff, callback, closure);
1090 if(gameInfo.variant == VariantSpartan) // in Spartan Chess Chancellor is used for Dragon King.
1091 Ferz(board, flags, rf, ff, callback, closure);
1093 Knight(board, flags, rf, ff, callback, closure);
1096 /* Shogi Rooks are ordinary Rooks */
1097 case SHOGI WhiteRook:
1098 case SHOGI BlackRook:
1099 case SHOGI WhitePRook:
1100 case SHOGI BlackPRook:
1103 Rook(board, flags, rf, ff, callback, closure);
1108 case SHOGI WhiteMother:
1109 case SHOGI BlackMother:
1111 Rook(board, flags, rf, ff, callback, closure);
1112 Bishop(board, flags, rf, ff, callback, closure);
1115 case SHOGI WhitePawn:
1116 StepForward(board, flags, rf, ff, callback, closure);
1119 case SHOGI BlackPawn:
1120 StepBackward(board, flags, rf, ff, callback, closure);
1124 if(gameInfo.variant != VariantMakruk && gameInfo.variant != VariantASEAN) goto commoner;
1125 case SHOGI WhiteFerz:
1126 Ferz(board, flags, rf, ff, callback, closure);
1127 StepForward(board, flags, rf, ff, callback, closure);
1131 if(gameInfo.variant != VariantMakruk && gameInfo.variant != VariantASEAN) goto commoner;
1132 case SHOGI BlackFerz:
1133 StepBackward(board, flags, rf, ff, callback, closure);
1137 /* [HGM] support Shatranj pieces */
1138 Ferz(board, flags, rf, ff, callback, closure);
1143 Knight(board, flags, rf, ff, callback, closure); // [HGM] superchess: use for Centaur
1146 case SHOGI WhiteMonarch:
1147 case SHOGI BlackMonarch:
1148 case SHOGI WhiteKing:
1149 case SHOGI BlackKing:
1152 Ferz(board, flags, rf, ff, callback, closure);
1153 Wazir(board, flags, rf, ff, callback, closure);
1156 case WhiteNightrider:
1157 case BlackNightrider:
1158 for (i = -1; i <= 1; i += 2)
1159 for (j = -1; j <= 1; j += 2)
1160 for (s = 1; s <= 2; s++) { int k;
1163 ft = ff + k*j*(3-s);
1164 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
1165 if (SameColor(board[rf][ff], board[rt][ft])) break;
1166 callback(board, flags, NormalMove,
1167 rf, ff, rt, ft, closure);
1168 if (board[rt][ft] != EmptySquare) break;
1174 Bishop(board, flags, rf, ff, callback, closure);
1175 Rook(board, flags, rf, ff, callback, closure);
1176 Knight(board, flags, rf, ff, callback, closure);
1179 // Use Lance as Berolina / Spartan Pawn.
1181 if(gameInfo.variant == VariantSuper) goto Amazon;
1182 if (rf < BOARD_HEIGHT-1 && BlackPiece(board[rf + 1][ff]))
1183 callback(board, flags,
1184 rf >= BOARD_HEIGHT-1-promoRank ? WhitePromotion : NormalMove,
1185 rf, ff, rf + 1, ff, closure);
1186 for (s = -1; s <= 1; s += 2) {
1187 if (rf < BOARD_HEIGHT-1 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT && board[rf + 1][ff + s] == EmptySquare)
1188 callback(board, flags,
1189 rf >= BOARD_HEIGHT-1-promoRank ? WhitePromotion : NormalMove,
1190 rf, ff, rf + 1, ff + s, closure);
1191 if (rf == 1 && ff + 2*s >= BOARD_LEFT && ff + 2*s < BOARD_RGHT && board[3][ff + 2*s] == EmptySquare )
1192 callback(board, flags, NormalMove, rf, ff, 3, ff + 2*s, closure);
1197 if(gameInfo.variant == VariantSuper) goto Amazon;
1198 if (rf > 0 && WhitePiece(board[rf - 1][ff]))
1199 callback(board, flags,
1200 rf <= promoRank ? BlackPromotion : NormalMove,
1201 rf, ff, rf - 1, ff, closure);
1202 for (s = -1; s <= 1; s += 2) {
1203 if (rf > 0 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT && board[rf - 1][ff + s] == EmptySquare)
1204 callback(board, flags,
1205 rf <= promoRank ? BlackPromotion : NormalMove,
1206 rf, ff, rf - 1, ff + s, closure);
1207 if (rf == BOARD_HEIGHT-2 && ff + 2*s >= BOARD_LEFT && ff + 2*s < BOARD_RGHT && board[rf-2][ff + 2*s] == EmptySquare )
1208 callback(board, flags, NormalMove, rf, ff, rf-2, ff + 2*s, closure);
1212 case SHOGI WhiteNothing:
1213 case SHOGI BlackNothing:
1214 case SHOGI WhiteLion:
1215 case SHOGI BlackLion:
1218 for(rt = rf - 2; rt <= rf + 2; rt++) for(ft = ff - 2; ft <= ff + 2; ft++) {
1219 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) continue;
1220 if (!(ff == ft && rf == rt) && SameColor(board[rf][ff], board[rt][ft])) continue;
1221 i = (killX >= 0 && (rt-killY)*(rt-killY) + (killX-ft)*(killX-ft) < 3); legNr += 2*i;
1222 callback(board, flags, (rt-rf)*(rt-rf) + (ff-ft)*(ff-ft) < 3 && board[rt][ft] != EmptySquare ? FirstLeg : NormalMove,
1223 rf, ff, rt, ft, closure);
1228 case SHOGI WhiteFalcon:
1229 case SHOGI BlackFalcon:
1230 case SHOGI WhitePDagger:
1231 case SHOGI BlackPDagger:
1232 SlideSideways(board, flags, rf, ff, callback, closure);
1233 StepVertical(board, flags, rf, ff, callback, closure);
1236 case SHOGI WhiteCobra:
1237 case SHOGI BlackCobra:
1238 StepVertical(board, flags, rf, ff, callback, closure);
1241 case SHOGI (PROMO WhiteFerz):
1242 if(gameInfo.variant == VariantShogi) goto WhiteGold;
1243 case SHOGI (PROMO BlackFerz):
1244 if(gameInfo.variant == VariantShogi) goto BlackGold;
1245 case SHOGI WhitePSword:
1246 case SHOGI BlackPSword:
1247 SlideVertical(board, flags, rf, ff, callback, closure);
1248 StepSideways(board, flags, rf, ff, callback, closure);
1251 case SHOGI WhiteUnicorn:
1252 case SHOGI BlackUnicorn:
1253 Ferz(board, flags, rf, ff, callback, closure);
1254 StepVertical(board, flags, rf, ff, callback, closure);
1257 case SHOGI WhiteMan:
1258 StepDiagForward(board, flags, rf, ff, callback, closure);
1259 StepVertical(board, flags, rf, ff, callback, closure);
1262 case SHOGI BlackMan:
1263 StepDiagBackward(board, flags, rf, ff, callback, closure);
1264 StepVertical(board, flags, rf, ff, callback, closure);
1267 case SHOGI WhiteHCrown:
1268 case SHOGI BlackHCrown:
1269 Bishop(board, flags, rf, ff, callback, closure);
1270 SlideSideways(board, flags, rf, ff, callback, closure);
1273 case SHOGI WhiteCrown:
1274 case SHOGI BlackCrown:
1275 Bishop(board, flags, rf, ff, callback, closure);
1276 SlideVertical(board, flags, rf, ff, callback, closure);
1279 case SHOGI WhiteHorned:
1280 Sting(board, flags, rf, ff, 1, 0, callback, closure);
1281 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1282 if(killX >= 0) break;
1283 Bishop(board, flags, rf, ff, callback, closure);
1284 SlideSideways(board, flags, rf, ff, callback, closure);
1285 SlideBackward(board, flags, rf, ff, callback, closure);
1288 case SHOGI BlackHorned:
1289 Sting(board, flags, rf, ff, -1, 0, callback, closure);
1290 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1291 if(killX >= 0) break;
1292 Bishop(board, flags, rf, ff, callback, closure);
1293 SlideSideways(board, flags, rf, ff, callback, closure);
1294 SlideForward(board, flags, rf, ff, callback, closure);
1297 case SHOGI WhiteEagle:
1298 Sting(board, flags, rf, ff, 1, 1, callback, closure);
1299 Sting(board, flags, rf, ff, 1, -1, callback, closure);
1300 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1301 if(killX >= 0) break;
1302 Rook(board, flags, rf, ff, callback, closure);
1303 SlideDiagBackward(board, flags, rf, ff, callback, closure);
1306 case SHOGI BlackEagle:
1307 Sting(board, flags, rf, ff, -1, 1, callback, closure);
1308 Sting(board, flags, rf, ff, -1, -1, callback, closure);
1309 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1310 if(killX >= 0) break;
1311 Rook(board, flags, rf, ff, callback, closure);
1312 SlideDiagForward(board, flags, rf, ff, callback, closure);
1315 case SHOGI WhiteDolphin:
1316 case SHOGI BlackHorse:
1317 SlideDiagBackward(board, flags, rf, ff, callback, closure);
1318 SlideVertical(board, flags, rf, ff, callback, closure);
1321 case SHOGI BlackDolphin:
1322 case SHOGI WhiteHorse:
1323 SlideDiagForward(board, flags, rf, ff, callback, closure);
1324 SlideVertical(board, flags, rf, ff, callback, closure);
1327 case SHOGI WhiteLance:
1328 SlideForward(board, flags, rf, ff, callback, closure);
1331 case SHOGI BlackLance:
1332 SlideBackward(board, flags, rf, ff, callback, closure);
1335 case WhiteFalcon: // [HGM] wild: for wildcards, self-capture symbolizes move to anywhere
1339 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1352 int rFilter, fFilter; // [HGM] speed: sorry, but I get a bit tired of this closure madness
1353 Board xqCheckers, nullBoard;
1355 extern void GenLegalCallback P((Board board, int flags, ChessMove kind,
1356 int rf, int ff, int rt, int ft,
1360 GenLegalCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1362 register GenLegalClosure *cl = (GenLegalClosure *) closure;
1364 if(rFilter >= 0 && rFilter != rt || fFilter >= 0 && fFilter != ft) return; // [HGM] speed: ignore moves with wrong to-square
1366 if (board[EP_STATUS] == EP_IRON_LION && (board[rt][ft] == WhiteLion || board[rt][ft] == BlackLion)) return; //[HGM] lion
1368 if (!(flags & F_IGNORE_CHECK) ) {
1369 int check, promo = (gameInfo.variant == VariantSpartan && kind == BlackPromotion);
1372 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++)
1373 kings += (board[r][f] == BlackKing);
1377 board[rf][ff] = BlackKing; // [HGM] spartan: promote to King before check-test
1379 check = CheckTest(board, flags, rf, ff, rt, ft,
1380 kind == WhiteCapturesEnPassant ||
1381 kind == BlackCapturesEnPassant);
1382 if(promo) board[rf][ff] = BlackLance;
1385 if (flags & F_ATOMIC_CAPTURE) {
1386 if (board[rt][ft] != EmptySquare ||
1387 kind == WhiteCapturesEnPassant || kind == BlackCapturesEnPassant) {
1389 ChessSquare king = (flags & F_WHITE_ON_MOVE) ? WhiteKing : BlackKing;
1390 if (board[rf][ff] == king) return;
1391 for (r = rt-1; r <= rt+1; r++) {
1392 for (f = ft-1; f <= ft+1; f++) {
1393 if (r >= 0 && r < BOARD_HEIGHT && f >= BOARD_LEFT && f < BOARD_RGHT &&
1394 board[r][f] == king) return;
1399 cl->cb(board, flags, kind, rf, ff, rt, ft, cl->cl);
1406 int captures; // [HGM] losers
1407 } LegalityTestClosure;
1410 /* Like GenPseudoLegal, but (1) include castling moves, (2) unless
1411 F_IGNORE_CHECK is set in the flags, omit moves that would leave the
1412 king in check, and (3) if F_ATOMIC_CAPTURE is set in the flags, omit
1413 moves that would destroy your own king. The CASTLE_OK flags are
1414 true if castling is not yet ruled out by a move of the king or
1415 rook. Return TRUE if the player on move is currently in check and
1416 F_IGNORE_CHECK is not set. [HGM] add castlingRights parameter */
1418 GenLegal (Board board, int flags, MoveCallback callback, VOIDSTAR closure, ChessSquare filter)
1421 int ff, ft, k, left, right, swap;
1422 int ignoreCheck = (flags & F_IGNORE_CHECK) != 0;
1423 ChessSquare wKing = WhiteKing, bKing = BlackKing, *castlingRights = board[CASTLING];
1424 int inCheck = !ignoreCheck && CheckTest(board, flags, -1, -1, -1, -1, FALSE); // kludge alert: this would mark pre-existing checkers if status==1
1429 xqCheckers[EP_STATUS] *= 2; // quasi: if previous CheckTest has been marking, we now set flag for suspending same checkers
1430 if(filter == EmptySquare) rFilter = fFilter = -1; // [HGM] speed: do not filter on square if we do not filter on piece
1431 GenPseudoLegal(board, flags, GenLegalCallback, (VOIDSTAR) &cl, filter);
1433 if (inCheck) return TRUE;
1435 /* Generate castling moves */
1436 if(gameInfo.variant == VariantKnightmate) { /* [HGM] Knightmate */
1437 wKing = WhiteUnicorn; bKing = BlackUnicorn;
1440 p = (flags & F_WHITE_ON_MOVE ? pieceDesc[wKing] : pieceDesc[bKing]);
1441 if(p && strchr(p, 'O')) return FALSE; // [HGM] gen: castlings were already generated from string
1443 for (ff = BOARD_WIDTH>>1; ff >= (BOARD_WIDTH-1)>>1; ff-- /*ics wild 1*/) {
1444 if ((flags & F_WHITE_ON_MOVE) &&
1445 (flags & F_WHITE_KCASTLE_OK) &&
1446 board[0][ff] == wKing &&
1447 board[0][ff + 1] == EmptySquare &&
1448 board[0][ff + 2] == EmptySquare &&
1449 board[0][BOARD_RGHT-3] == EmptySquare &&
1450 board[0][BOARD_RGHT-2] == EmptySquare &&
1451 board[0][BOARD_RGHT-1] == WhiteRook &&
1452 castlingRights[0] != NoRights && /* [HGM] check rights */
1453 ( castlingRights[2] == ff || castlingRights[6] == ff ) &&
1455 (!CheckTest(board, flags, 0, ff, 0, ff + 1, FALSE) &&
1456 !CheckTest(board, flags, 0, ff, 0, BOARD_RGHT-3, FALSE) &&
1457 (gameInfo.variant != VariantJanus || !CheckTest(board, flags, 0, ff, 0, BOARD_RGHT-2, FALSE)) &&
1458 !CheckTest(board, flags, 0, ff, 0, ff + 2, FALSE)))) {
1460 callback(board, flags,
1461 ff==BOARD_WIDTH>>1 ? WhiteKingSideCastle : WhiteKingSideCastleWild,
1462 0, ff, 0, ff + ((gameInfo.boardWidth+2)>>2) + (gameInfo.variant == VariantJanus), closure);
1464 if ((flags & F_WHITE_ON_MOVE) &&
1465 (flags & F_WHITE_QCASTLE_OK) &&
1466 board[0][ff] == wKing &&
1467 board[0][ff - 1] == EmptySquare &&
1468 board[0][ff - 2] == EmptySquare &&
1469 board[0][BOARD_LEFT+2] == EmptySquare &&
1470 board[0][BOARD_LEFT+1] == EmptySquare &&
1471 board[0][BOARD_LEFT+0] == WhiteRook &&
1472 castlingRights[1] != NoRights && /* [HGM] check rights */
1473 ( castlingRights[2] == ff || castlingRights[6] == ff ) &&
1475 (!CheckTest(board, flags, 0, ff, 0, ff - 1, FALSE) &&
1476 !CheckTest(board, flags, 0, ff, 0, BOARD_LEFT+3, FALSE) &&
1477 !CheckTest(board, flags, 0, ff, 0, ff - 2, FALSE)))) {
1479 callback(board, flags,
1480 ff==BOARD_WIDTH>>1 ? WhiteQueenSideCastle : WhiteQueenSideCastleWild,
1481 0, ff, 0, ff - ((gameInfo.boardWidth+2)>>2), closure);
1483 if (!(flags & F_WHITE_ON_MOVE) &&
1484 (flags & F_BLACK_KCASTLE_OK) &&
1485 board[BOARD_HEIGHT-1][ff] == bKing &&
1486 board[BOARD_HEIGHT-1][ff + 1] == EmptySquare &&
1487 board[BOARD_HEIGHT-1][ff + 2] == EmptySquare &&
1488 board[BOARD_HEIGHT-1][BOARD_RGHT-3] == EmptySquare &&
1489 board[BOARD_HEIGHT-1][BOARD_RGHT-2] == EmptySquare &&
1490 board[BOARD_HEIGHT-1][BOARD_RGHT-1] == BlackRook &&
1491 castlingRights[3] != NoRights && /* [HGM] check rights */
1492 ( castlingRights[5] == ff || castlingRights[7] == ff ) &&
1494 (!CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff + 1, FALSE) &&
1495 !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, BOARD_RGHT-3, FALSE) &&
1496 (gameInfo.variant != VariantJanus || !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, BOARD_RGHT-2, FALSE)) &&
1497 !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff + 2, FALSE)))) {
1499 callback(board, flags,
1500 ff==BOARD_WIDTH>>1 ? BlackKingSideCastle : BlackKingSideCastleWild,
1501 BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff + ((gameInfo.boardWidth+2)>>2) + (gameInfo.variant == VariantJanus), closure);
1503 if (!(flags & F_WHITE_ON_MOVE) &&
1504 (flags & F_BLACK_QCASTLE_OK) &&
1505 board[BOARD_HEIGHT-1][ff] == bKing &&
1506 board[BOARD_HEIGHT-1][ff - 1] == EmptySquare &&
1507 board[BOARD_HEIGHT-1][ff - 2] == EmptySquare &&
1508 board[BOARD_HEIGHT-1][BOARD_LEFT+2] == EmptySquare &&
1509 board[BOARD_HEIGHT-1][BOARD_LEFT+1] == EmptySquare &&
1510 board[BOARD_HEIGHT-1][BOARD_LEFT+0] == BlackRook &&
1511 castlingRights[4] != NoRights && /* [HGM] check rights */
1512 ( castlingRights[5] == ff || castlingRights[7] == ff ) &&
1514 (!CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff - 1, FALSE) &&
1515 !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, BOARD_LEFT+3, FALSE) &&
1516 !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff - 2, FALSE)))) {
1518 callback(board, flags,
1519 ff==BOARD_WIDTH>>1 ? BlackQueenSideCastle : BlackQueenSideCastleWild,
1520 BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff - ((gameInfo.boardWidth+2)>>2), closure);
1524 if((swap = gameInfo.variant == VariantSChess) || flags & F_FRC_TYPE_CASTLING) {
1526 /* generate all potential FRC castling moves (KxR), ignoring flags */
1527 /* [HGM] test if the Rooks we find have castling rights */
1528 /* In S-Chess we generate RxK for allowed castlings, for gating at Rook square */
1531 if ((flags & F_WHITE_ON_MOVE) != 0) {
1532 ff = castlingRights[2]; /* King file if we have any rights */
1533 if(ff != NoRights && board[0][ff] == WhiteKing) {
1534 if (appData.debugMode) {
1535 fprintf(debugFP, "FRC castling, %d %d %d %d %d %d\n",
1536 castlingRights[0],castlingRights[1],ff,castlingRights[3],castlingRights[4],castlingRights[5]);
1538 ft = castlingRights[0]; /* Rook file if we have H-side rights */
1540 right = BOARD_RGHT-2;
1541 if(ff == BOARD_RGHT-2) left = right = ff-1; /* special case */
1542 for(k=left; k<=right && ft != NoRights; k++) /* first test if blocked */
1543 if(k != ft && board[0][k] != EmptySquare) ft = NoRights;
1544 for(k=left; k<right && ft != NoRights; k++) /* then if not checked */
1545 if(!ignoreCheck && CheckTest(board, flags, 0, ff, 0, k, FALSE)) ft = NoRights;
1546 if(ft != NoRights && board[0][ft] == WhiteRook) {
1547 if(flags & F_FRC_TYPE_CASTLING) callback(board, flags, WhiteHSideCastleFR, 0, ff, 0, ft, closure);
1548 if(swap) callback(board, flags, WhiteHSideCastleFR, 0, ft, 0, ff, closure);
1551 ft = castlingRights[1]; /* Rook file if we have A-side rights */
1552 left = BOARD_LEFT+2;
1554 if(ff <= BOARD_LEFT+2) { left = ff+1; right = BOARD_LEFT+3; }
1555 for(k=left; k<=right && ft != NoRights; k++) /* first test if blocked */
1556 if(k != ft && board[0][k] != EmptySquare) ft = NoRights;
1557 if(ft == 0 && ff != 1 && board[0][1] != EmptySquare) ft = NoRights; /* Rook can be blocked on b1 */
1558 if(ff > BOARD_LEFT+2)
1559 for(k=left+1; k<=right && ft != NoRights; k++) /* then if not checked */
1560 if(!ignoreCheck && CheckTest(board, flags, 0, ff, 0, k, FALSE)) ft = NoRights;
1561 if(ft != NoRights && board[0][ft] == WhiteRook) {
1562 if(flags & F_FRC_TYPE_CASTLING) callback(board, flags, WhiteASideCastleFR, 0, ff, 0, ft, closure);
1563 if(swap) callback(board, flags, WhiteASideCastleFR, 0, ft, 0, ff, closure);
1567 ff = castlingRights[5]; /* King file if we have any rights */
1568 if(ff != NoRights && board[BOARD_HEIGHT-1][ff] == BlackKing) {
1569 ft = castlingRights[3]; /* Rook file if we have H-side rights */
1571 right = BOARD_RGHT-2;
1572 if(ff == BOARD_RGHT-2) left = right = ff-1; /* special case */
1573 for(k=left; k<=right && ft != NoRights; k++) /* first test if blocked */
1574 if(k != ft && board[BOARD_HEIGHT-1][k] != EmptySquare) ft = NoRights;
1575 for(k=left; k<right && ft != NoRights; k++) /* then if not checked */
1576 if(!ignoreCheck && CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, k, FALSE)) ft = NoRights;
1577 if(ft != NoRights && board[BOARD_HEIGHT-1][ft] == BlackRook) {
1578 if(flags & F_FRC_TYPE_CASTLING) callback(board, flags, BlackHSideCastleFR, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ft, closure);
1579 if(swap) callback(board, flags, BlackHSideCastleFR, BOARD_HEIGHT-1, ft, BOARD_HEIGHT-1, ff, closure);
1582 ft = castlingRights[4]; /* Rook file if we have A-side rights */
1583 left = BOARD_LEFT+2;
1585 if(ff <= BOARD_LEFT+2) { left = ff+1; right = BOARD_LEFT+3; }
1586 for(k=left; k<=right && ft != NoRights; k++) /* first test if blocked */
1587 if(k != ft && board[BOARD_HEIGHT-1][k] != EmptySquare) ft = NoRights;
1588 if(ft == 0 && ff != 1 && board[BOARD_HEIGHT-1][1] != EmptySquare) ft = NoRights; /* Rook can be blocked on b8 */
1589 if(ff > BOARD_LEFT+2)
1590 for(k=left+1; k<=right && ft != NoRights; k++) /* then if not checked */
1591 if(!ignoreCheck && CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, k, FALSE)) ft = NoRights;
1592 if(ft != NoRights && board[BOARD_HEIGHT-1][ft] == BlackRook) {
1593 if(flags & F_FRC_TYPE_CASTLING) callback(board, flags, BlackASideCastleFR, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ft, closure);
1594 if(swap) callback(board, flags, BlackASideCastleFR, BOARD_HEIGHT-1, ft, BOARD_HEIGHT-1, ff, closure);
1611 extern void CheckTestCallback P((Board board, int flags, ChessMove kind,
1612 int rf, int ff, int rt, int ft,
1617 CheckTestCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1619 register CheckTestClosure *cl = (CheckTestClosure *) closure;
1621 if (rt == cl->rking && ft == cl->fking) {
1622 if(xqCheckers[EP_STATUS] >= 2 && xqCheckers[rf][ff]) return; // checker is piece with suspended checking power
1624 xqCheckers[rf][ff] = xqCheckers[EP_STATUS] & 1; // remember who is checking (if status == 1)
1626 if( board[EP_STATUS] == EP_ROYAL_LION && (board[rt][ft] == WhiteLion || board[rt][ft] == BlackLion)
1627 && (gameInfo.variant != VariantLion || board[rf][ff] != WhiteKing && board[rf][ff] != BlackKing) )
1628 cl->check++; // [HGM] lion: forbidden counterstrike against Lion equated to putting yourself in check
1632 /* If the player on move were to move from (rf, ff) to (rt, ft), would
1633 he leave himself in check? Or if rf == -1, is the player on move
1634 in check now? enPassant must be TRUE if the indicated move is an
1635 e.p. capture. The possibility of castling out of a check along the
1636 back rank is not accounted for (i.e., we still return nonzero), as
1637 this is illegal anyway. Return value is the number of times the
1638 king is in check. */
1640 CheckTest (Board board, int flags, int rf, int ff, int rt, int ft, int enPassant)
1642 CheckTestClosure cl;
1643 ChessSquare king = flags & F_WHITE_ON_MOVE ? WhiteKing : BlackKing;
1644 ChessSquare captured = EmptySquare, ep=0, trampled=0;
1645 int saveKill = killX;
1646 /* Suppress warnings on uninitialized variables */
1648 if(gameInfo.variant == VariantXiangqi)
1649 king = flags & F_WHITE_ON_MOVE ? WhiteWazir : BlackWazir;
1650 if(gameInfo.variant == VariantKnightmate)
1651 king = flags & F_WHITE_ON_MOVE ? WhiteUnicorn : BlackUnicorn;
1652 if(gameInfo.variant == VariantChu || gameInfo.variant == VariantShogi) { // strictly speaking this is not needed, as Chu officially has no check
1653 int r, f, k = king, royals=0, prince = flags & F_WHITE_ON_MOVE ? WhiteMonarch : BlackMonarch;
1654 if(gameInfo.variant == VariantShogi) prince -= 11; // White/BlackFalcon
1655 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++) {
1656 if(board[r][f] == k || board[r][f] == prince) {
1657 if(++royals > 1) return FALSE; // no check if we have two royals (ignores double captureby Lion!)
1658 king = board[r][f]; // remember hich one we had
1665 captured = board[rf][ft];
1666 board[rf][ft] = EmptySquare;
1668 captured = board[rt][ft];
1669 if(killX >= 0) { trampled = board[killY][killX]; board[killY][killX] = EmptySquare; killX = -1; }
1671 if(rf == DROP_RANK) board[rt][ft] = ff; else { // [HGM] drop
1672 board[rt][ft] = board[rf][ff];
1673 if(rf != rt || ff != ft) board[rf][ff] = EmptySquare;
1675 ep = board[EP_STATUS];
1676 if( captured == WhiteLion || captured == BlackLion ) { // [HGM] lion: Chu Lion-capture rules
1677 ChessSquare victim = saveKill < 0 ? EmptySquare : trampled;
1678 if( (board[rt][ft] == WhiteLion || board[rt][ft] == BlackLion) && // capturer is Lion
1679 (ff - ft > 1 || ft - ff > 1 || rf - rt > 1 || rt - rf > 1) && // captures from a distance
1680 (victim == EmptySquare || victim == WhitePawn || victim == BlackPawn // no or worthless 'bridge'
1681 || victim == WhiteCobra || victim == BlackCobra) ) // (Pawn or Go Between)
1682 board[EP_STATUS] = EP_ROYAL_LION; // on distant Lion x Lion victim must not be pseudo-legally protected
1686 /* For compatibility with ICS wild 9, we scan the board in the
1687 order a1, a2, a3, ... b1, b2, ..., h8 to find the first king,
1688 and we test only whether that one is in check. */
1689 for (cl.fking = BOARD_LEFT+0; cl.fking < BOARD_RGHT; cl.fking++)
1690 for (cl.rking = 0; cl.rking < BOARD_HEIGHT; cl.rking++) {
1691 if (board[cl.rking][cl.fking] == king) {
1693 if(gameInfo.variant == VariantXiangqi) {
1694 /* [HGM] In Xiangqi opposing Kings means check as well */
1696 dir = (king >= BlackPawn) ? -1 : 1;
1697 for( i=cl.rking+dir; i>=0 && i<BOARD_HEIGHT &&
1698 board[i][cl.fking] == EmptySquare; i+=dir );
1699 if(i>=0 && i<BOARD_HEIGHT &&
1700 board[i][cl.fking] == (dir>0 ? BlackWazir : WhiteWazir) )
1703 GenPseudoLegal(board, flags ^ F_WHITE_ON_MOVE, CheckTestCallback, (VOIDSTAR) &cl, EmptySquare);
1704 if(gameInfo.variant != VariantSpartan || cl.check == 0) // in Spartan Chess go on to test if other King is checked too
1705 goto undo_move; /* 2-level break */
1712 if(rf != DROP_RANK) // [HGM] drop
1713 board[rf][ff] = board[rt][ft];
1715 board[rf][ft] = captured;
1716 board[rt][ft] = EmptySquare;
1718 if(saveKill >= 0) board[killY][killX = saveKill] = trampled;
1719 board[rt][ft] = captured;
1721 board[EP_STATUS] = ep;
1724 return cl.fking < BOARD_RGHT ? cl.check : 1000; // [HGM] atomic: return 1000 if we have no king
1728 HasLion (Board board, int flags)
1730 int lion = F_WHITE_ON_MOVE & flags ? WhiteLion : BlackLion;
1732 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++)
1733 if(board[r][f] == lion) return 1;
1738 LegalDrop (Board board, int flags, ChessSquare piece, int rt, int ft)
1739 { // [HGM] put drop legality testing in separate routine for clarity
1741 if(appData.debugMode) fprintf(debugFP, "LegalDrop: %d @ %d,%d)\n", piece, ft, rt);
1742 if(board[rt][ft] != EmptySquare) return ImpossibleMove; // must drop to empty square
1743 n = PieceToNumber(piece);
1744 if((gameInfo.holdingsWidth == 0 || (flags & F_WHITE_ON_MOVE ? board[n][BOARD_WIDTH-1] : board[BOARD_HEIGHT-1-n][0]) != piece)
1745 && gameInfo.variant != VariantBughouse) // in bughouse we don't check for availability, because ICS doesn't always tell us
1746 return ImpossibleMove; // piece not available
1747 if(gameInfo.variant == VariantShogi) { // in Shogi lots of drops are forbidden!
1748 if((piece == WhitePawn || piece == WhiteQueen) && rt == BOARD_HEIGHT-1 ||
1749 (piece == BlackPawn || piece == BlackQueen) && rt == 0 ||
1750 piece == WhiteKnight && rt > BOARD_HEIGHT-3 ||
1751 piece == BlackKnight && rt < 2 ) return IllegalMove; // e.g. where dropped piece has no moves
1752 if(piece == WhitePawn || piece == BlackPawn) {
1753 int r, max = 1 + (BOARD_HEIGHT == 7); // two Pawns per file in Tori!
1754 for(r=1; r<BOARD_HEIGHT-1; r++)
1755 if(!(max -= (board[r][ft] == piece))) return IllegalMove; // or there already is a Pawn in file
1756 // should still test if we mate with this Pawn
1758 } else if(gameInfo.variant == VariantSChess) { // only back-rank drops
1759 if (rt != (piece < BlackPawn ? 0 : BOARD_HEIGHT-1)) return IllegalMove;
1761 if( (piece == WhitePawn || piece == BlackPawn) &&
1762 (rt == 0 || rt == BOARD_HEIGHT -1 ) )
1763 return IllegalMove; /* no pawn drops on 1st/8th */
1765 if(appData.debugMode) fprintf(debugFP, "LegalDrop: %d @ %d,%d)\n", piece, ft, rt);
1766 if (!(flags & F_IGNORE_CHECK) &&
1767 CheckTest(board, flags, DROP_RANK, piece, rt, ft, FALSE) ) return IllegalMove;
1768 return flags & F_WHITE_ON_MOVE ? WhiteDrop : BlackDrop;
1771 extern void LegalityTestCallback P((Board board, int flags, ChessMove kind,
1772 int rf, int ff, int rt, int ft,
1776 LegalityTestCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1778 register LegalityTestClosure *cl = (LegalityTestClosure *) closure;
1780 if(board[rt][ft] != EmptySquare || kind==WhiteCapturesEnPassant || kind==BlackCapturesEnPassant)
1781 cl->captures++; // [HGM] losers: count legal captures
1782 if (rf == cl->rf && ff == cl->ff && rt == cl->rt && ft == cl->ft)
1787 LegalityTest (Board board, int flags, int rf, int ff, int rt, int ft, int promoChar)
1789 LegalityTestClosure cl; ChessSquare piece, filterPiece;
1791 if(quickFlag) flags = flags & ~1 | quickFlag & 1; // [HGM] speed: in quick mode quickFlag specifies side-to-move.
1792 if(rf == DROP_RANK) return LegalDrop(board, flags, ff, rt, ft);
1793 piece = filterPiece = board[rf][ff];
1794 if(PieceToChar(piece) == '~') filterPiece = DEMOTED(piece);
1796 /* [HGM] Cobra and Falcon are wildcard pieces; consider all their moves legal */
1797 /* (perhaps we should disallow moves that obviously leave us in check?) */
1798 if((piece == WhiteFalcon || piece == BlackFalcon ||
1799 piece == WhiteCobra || piece == BlackCobra) && gameInfo.variant != VariantChu && !pieceDesc[piece])
1800 return CheckTest(board, flags, rf, ff, rt, ft, FALSE) ? IllegalMove : NormalMove;
1804 cl.rt = rFilter = rt; // [HGM] speed: filter on to-square
1805 cl.ft = fFilter = ft;
1806 cl.kind = IllegalMove;
1807 cl.captures = 0; // [HGM] losers: prepare to count legal captures.
1808 if(flags & F_MANDATORY_CAPTURE) filterPiece = EmptySquare; // [HGM] speed: do not filter in suicide, to find all captures
1809 GenLegal(board, flags, LegalityTestCallback, (VOIDSTAR) &cl, filterPiece);
1810 if((flags & F_MANDATORY_CAPTURE) && cl.captures && board[rt][ft] == EmptySquare
1811 && cl.kind != WhiteCapturesEnPassant && cl.kind != BlackCapturesEnPassant)
1812 return(IllegalMove); // [HGM] losers: if there are legal captures, non-capts are illegal
1814 if(promoChar == 'x') promoChar = NULLCHAR; // [HGM] is this ever the case?
1815 if(gameInfo.variant == VariantSChess && promoChar && promoChar != '=' && board[rf][ff] != WhitePawn && board[rf][ff] != BlackPawn) {
1816 if(board[rf][ff] < BlackPawn) { // white
1817 if(rf != 0) return IllegalMove; // must be on back rank
1818 if(!(board[VIRGIN][ff] & VIRGIN_W)) return IllegalMove; // non-virgin
1819 if(board[PieceToNumber(CharToPiece(ToUpper(promoChar)))][BOARD_WIDTH-2] == 0) return ImpossibleMove;// must be in stock
1820 if(cl.kind == WhiteHSideCastleFR && (ff == BOARD_RGHT-2 || ff == BOARD_RGHT-3)) return ImpossibleMove;
1821 if(cl.kind == WhiteASideCastleFR && (ff == BOARD_LEFT+2 || ff == BOARD_LEFT+3)) return ImpossibleMove;
1823 if(rf != BOARD_HEIGHT-1) return IllegalMove;
1824 if(!(board[VIRGIN][ff] & VIRGIN_B)) return IllegalMove; // non-virgin
1825 if(board[BOARD_HEIGHT-1-PieceToNumber(CharToPiece(ToLower(promoChar)))][1] == 0) return ImpossibleMove;
1826 if(cl.kind == BlackHSideCastleFR && (ff == BOARD_RGHT-2 || ff == BOARD_RGHT-3)) return ImpossibleMove;
1827 if(cl.kind == BlackASideCastleFR && (ff == BOARD_LEFT+2 || ff == BOARD_LEFT+3)) return ImpossibleMove;
1830 if(gameInfo.variant == VariantChu) {
1831 if(cl.kind != NormalMove || promoChar == NULLCHAR || promoChar == '=') return cl.kind;
1832 if(promoChar != '+')
1833 return CharToPiece(promoChar) == EmptySquare ? ImpossibleMove : IllegalMove;
1834 if(PieceToChar(CHUPROMOTED(board[rf][ff])) != '+') {
1835 if(PieceToChar(CHUPROMOTED (board[rf][ff] < BlackPawn ? WhitePawn : BlackPawn)) != '.')
1836 return ImpossibleMove;
1838 return flags & F_WHITE_ON_MOVE ? WhitePromotion : BlackPromotion;
1840 if(gameInfo.variant == VariantShogi) {
1841 /* [HGM] Shogi promotions. '=' means defer */
1842 if(rf != DROP_RANK && cl.kind == NormalMove) {
1843 ChessSquare piece = board[rf][ff];
1844 int zone = BOARD_HEIGHT/3 + (BOARD_HEIGHT == 8);
1846 if(promoChar == PieceToChar(BlackQueen)) promoChar = NULLCHAR; /* [HGM] Kludge */
1847 if(promoChar == 'd' && (piece == WhiteRook || piece == BlackRook) ||
1848 promoChar == 'h' && (piece == WhiteBishop || piece == BlackBishop) ||
1849 promoChar == 'g' && (piece <= WhiteFerz || piece <= BlackFerz && piece >= BlackPawn) )
1850 promoChar = '+'; // allowed ICS notations
1851 if(appData.debugMode)fprintf(debugFP,"SHOGI promoChar = %c\n", promoChar ? promoChar : '-');
1852 if(promoChar != NULLCHAR && promoChar != '+' && promoChar != '=')
1853 return CharToPiece(promoChar) == EmptySquare ? ImpossibleMove : IllegalMove;
1854 else if(flags & F_WHITE_ON_MOVE) {
1855 if( (int) piece < (int) WhiteWazir &&
1856 (rf >= BOARD_HEIGHT - zone || rt >= BOARD_HEIGHT - zone) ) {
1857 if( (piece == WhitePawn || piece == WhiteQueen) && rt > BOARD_HEIGHT-2 ||
1858 piece == WhiteKnight && rt > BOARD_HEIGHT-3) /* promotion mandatory */
1859 cl.kind = promoChar == '=' ? IllegalMove : WhitePromotion;
1860 else /* promotion optional, default is defer */
1861 cl.kind = promoChar == '+' ? WhitePromotion : WhiteNonPromotion;
1862 } else cl.kind = promoChar == '+' ? IllegalMove : NormalMove;
1864 if( (int) piece < (int) BlackWazir && (rf < zone || rt < zone) ) {
1865 if( (piece == BlackPawn || piece == BlackQueen) && rt < 1 ||
1866 piece == BlackKnight && rt < 2 ) /* promotion obligatory */
1867 cl.kind = promoChar == '=' ? IllegalMove : BlackPromotion;
1868 else /* promotion optional, default is defer */
1869 cl.kind = promoChar == '+' ? BlackPromotion : BlackNonPromotion;
1870 } else cl.kind = promoChar == '+' ? IllegalMove : NormalMove;
1874 if (promoChar != NULLCHAR) {
1875 if(cl.kind == NormalMove && promoChar == '+') { // allow shogi-style promotion is pieceToChar specifies them
1876 ChessSquare piece = board[rf][ff];
1877 if(piece < BlackPawn ? piece > WhiteMan : piece > BlackMan) return ImpossibleMove; // already promoted
1878 // should test if in zone, really
1879 if(gameInfo.variant == VariantChuChess && (piece == WhiteKnight || piece == BlackKnight) && HasLion(board, flags))
1881 if(PieceToChar(PROMOTED(piece)) == '+') return flags & F_WHITE_ON_MOVE ? WhitePromotion : BlackPromotion;
1883 if(promoChar == '=') cl.kind = IllegalMove; else // [HGM] shogi: no deferred promotion outside Shogi
1884 if (cl.kind == WhitePromotion || cl.kind == BlackPromotion) {
1885 ChessSquare piece = CharToPiece(flags & F_WHITE_ON_MOVE ? ToUpper(promoChar) : ToLower(promoChar));
1886 if(piece == EmptySquare)
1887 cl.kind = ImpossibleMove; // non-existing piece
1888 if(gameInfo.variant == VariantChuChess && promoChar == 'l' && HasLion(board, flags)) {
1889 cl.kind = IllegalMove; // no two Lions
1890 } else if(gameInfo.variant == VariantSpartan && cl.kind == BlackPromotion ) {
1891 if(promoChar != PieceToChar(BlackKing)) {
1892 if(CheckTest(board, flags, rf, ff, rt, ft, FALSE)) cl.kind = IllegalMove; // [HGM] spartan: only promotion to King was possible
1893 if(piece == BlackLance) cl.kind = ImpossibleMove;
1894 } else { // promotion to King allowed only if we do not have two yet
1895 int r, f, kings = 0;
1896 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++) kings += (board[r][f] == BlackKing);
1897 if(kings == 2) cl.kind = IllegalMove;
1899 } else if(piece == WhitePawn && rt == BOARD_HEIGHT-1 ||
1900 piece == BlackPawn && rt == 0) cl.kind = IllegalMove; // cannot stay Pawn on last rank in any variant
1901 else if((piece == WhiteUnicorn || piece == BlackUnicorn) && gameInfo.variant == VariantKnightmate)
1902 cl.kind = IllegalMove; // promotion to Royal Knight not allowed
1903 else if((piece == WhiteKing || piece == BlackKing) && gameInfo.variant != VariantSuicide && gameInfo.variant != VariantGiveaway)
1904 cl.kind = IllegalMove; // promotion to King usually not allowed
1906 cl.kind = IllegalMove;
1916 extern void MateTestCallback P((Board board, int flags, ChessMove kind,
1917 int rf, int ff, int rt, int ft,
1921 MateTestCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1923 register MateTestClosure *cl = (MateTestClosure *) closure;
1928 /* Return MT_NONE, MT_CHECK, MT_CHECKMATE, or MT_STALEMATE */
1930 MateTest (Board board, int flags)
1933 int inCheck, r, f, myPieces=0, hisPieces=0, nrKing=0;
1934 ChessSquare king = flags & F_WHITE_ON_MOVE ? WhiteKing : BlackKing;
1936 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++) {
1937 // [HGM] losers: Count pieces and kings, to detect other unorthodox winning conditions
1938 nrKing += (board[r][f] == king); // stm has king
1939 if( board[r][f] != EmptySquare ) {
1940 if((int)board[r][f] <= (int)king && (int)board[r][f] >= (int)king - (int)WhiteKing + (int)WhitePawn)
1945 switch(gameInfo.variant) { // [HGM] losers: extinction wins
1946 case VariantShatranj:
1947 if(hisPieces == 1) return myPieces > 1 ? MT_BARE : MT_DRAW;
1951 if(nrKing == 0) return MT_NOKING;
1954 if(myPieces == 1) return MT_BARE;
1957 inCheck = GenLegal(board, flags, MateTestCallback, (VOIDSTAR) &cl, EmptySquare);
1958 // [HGM] 3check: yet to do!
1960 return inCheck ? MT_CHECK : MT_NONE;
1962 if(gameInfo.holdingsWidth && gameInfo.variant != VariantSuper && gameInfo.variant != VariantGreat
1963 && gameInfo.variant != VariantSChess && gameInfo.variant != VariantGrand) { // drop game
1964 int r, f, n, holdings = flags & F_WHITE_ON_MOVE ? BOARD_WIDTH-1 : 0;
1965 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++) if(board[r][f] == EmptySquare) // all empty squares
1966 for(n=0; n<BOARD_HEIGHT; n++) // all pieces in hand
1967 if(board[n][holdings] != EmptySquare) {
1968 int moveType = LegalDrop(board, flags, board[n][holdings], r, f);
1969 if(moveType == WhiteDrop || moveType == BlackDrop) return (inCheck ? MT_CHECK : MT_NONE); // we have legal drop
1972 if(gameInfo.variant == VariantSuicide) // [HGM] losers: always stalemate, since no check, but result varies
1973 return myPieces == hisPieces ? MT_STALEMATE :
1974 myPieces > hisPieces ? MT_STAINMATE : MT_STEALMATE;
1975 else if(gameInfo.variant == VariantLosers) return inCheck ? MT_TRICKMATE : MT_STEALMATE;
1976 else if(gameInfo.variant == VariantGiveaway) return MT_STEALMATE; // no check exists, stalemated = win
1978 return inCheck ? MT_CHECKMATE
1979 : (gameInfo.variant == VariantXiangqi || gameInfo.variant == VariantShatranj || IS_SHOGI(gameInfo.variant)) ?
1980 MT_STAINMATE : MT_STALEMATE;
1985 extern void DisambiguateCallback P((Board board, int flags, ChessMove kind,
1986 int rf, int ff, int rt, int ft,
1990 DisambiguateCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1992 register DisambiguateClosure *cl = (DisambiguateClosure *) closure;
1993 int wildCard = FALSE; ChessSquare piece = board[rf][ff];
1994 extern int kifu; // in parser.c
1996 // [HGM] wild: for wild-card pieces rt and rf are dummies
1997 if(piece == WhiteFalcon || piece == BlackFalcon ||
1998 piece == WhiteCobra || piece == BlackCobra)
2001 if ((cl->pieceIn == EmptySquare || cl->pieceIn == board[rf][ff]
2002 || PieceToChar(board[rf][ff]) == '~'
2003 && cl->pieceIn == (ChessSquare)(DEMOTED(board[rf][ff]))
2005 (cl->rfIn == -1 || cl->rfIn == rf) &&
2006 (cl->ffIn == -1 || cl->ffIn == ff) &&
2007 (cl->rtIn == -1 || cl->rtIn == rt || wildCard) &&
2008 (cl->ftIn == -1 || cl->ftIn == ft || wildCard)) {
2010 if(cl->count && rf == cl->rf && ff == cl->ff) return; // duplicate move
2012 if(cl->count == 1 && kifu & 0x7E && cl->rfIn == -1 && cl->ffIn == -1) { // traditional Shogi disambiguation required
2013 int this = 1, other = 1;
2014 if(kifu & 2) this &= (flags & 1 ? rt > rf : rt < rf), other &= (flags & 1 ? cl->rt > cl->rf : cl->rt < cl->rf);
2015 if(kifu & 4) this &= (flags & 1 ? rt < rf : rt > rf), other &= (flags & 1 ? cl->rt < cl->rf : cl->rt > cl->rf);
2016 if(kifu & 8) this &= (rf == rt), other &= (cl->rt == cl->rf);
2017 if(kifu & 0x10) this &= (flags & 1 ? ft <= ff : ft >= ff), other &= (flags & 1 ? cl->ft <= cl->ff : cl->ft >= cl->ff);
2018 if(kifu & 0x20) this &= (flags & 1 ? ft >= ff : ft <= ff), other &= (flags & 1 ? cl->ft >= cl->ff : cl->ft <= cl->ff);
2019 if(kifu & 0x40) this &= (ft == ff), other &= (cl->ft == cl->ff); // should never be used
2020 if(!other) cl->count--; // the old move did not satisfy the requested relative position, erase it
2021 if(!this) return; // the current move does not satisfy the requested relative position, ignore it
2025 if(cl->count == 1 || board[rt][ft] != EmptySquare) {
2026 // [HGM] oneclick: if multiple moves, be sure we remember capture
2027 cl->piece = board[rf][ff];
2030 cl->rt = wildCard ? cl->rtIn : rt;
2031 cl->ft = wildCard ? cl->ftIn : ft;
2034 cl->captures += (board[rt][ft] != EmptySquare); // [HGM] oneclick: count captures
2039 Disambiguate (Board board, int flags, DisambiguateClosure *closure)
2041 int illegal = 0; char c = closure->promoCharIn;
2043 if(quickFlag) flags = flags & ~1 | quickFlag & 1; // [HGM] speed: in quick mode quickFlag specifies side-to-move.
2044 closure->count = closure->captures = 0;
2045 closure->rf = closure->ff = closure->rt = closure->ft = 0;
2046 closure->kind = ImpossibleMove;
2047 rFilter = closure->rtIn; // [HGM] speed: only consider moves to given to-square
2048 fFilter = closure->ftIn;
2049 if(quickFlag) { // [HGM] speed: try without check test first, because if that is not ambiguous, we are happy
2050 GenLegal(board, flags|F_IGNORE_CHECK, DisambiguateCallback, (VOIDSTAR) closure, closure->pieceIn);
2051 if(closure->count > 1) { // gamble did not pay off. retry with check test to resolve ambiguity
2052 closure->count = closure->captures = 0;
2053 closure->rf = closure->ff = closure->rt = closure->ft = 0;
2054 closure->kind = ImpossibleMove;
2055 GenLegal(board, flags, DisambiguateCallback, (VOIDSTAR) closure, closure->pieceIn); // [HGM] speed: only pieces of requested type
2058 GenLegal(board, flags, DisambiguateCallback, (VOIDSTAR) closure, closure->pieceIn); // [HGM] speed: only pieces of requested type
2059 if (closure->count == 0) {
2060 /* See if it's an illegal move due to check */
2062 GenLegal(board, flags|F_IGNORE_CHECK, DisambiguateCallback, (VOIDSTAR) closure, closure->pieceIn);
2063 if (closure->count == 0) {
2064 /* No, it's not even that */
2065 if(!appData.testLegality && !pieceDefs && closure->pieceIn != EmptySquare) {
2066 int f, r; // if there is only a single piece of the requested type on the board, use that
2067 closure->rt = closure->rtIn, closure->ft = closure->ftIn;
2068 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++)
2069 if(board[r][f] == closure->pieceIn) closure->count++, closure->rf = r, closure->ff = f;
2070 if(closure->count > 1) illegal = 0; // ambiguous
2072 if(closure->count == 0) {
2073 if (appData.debugMode) { int i, j;
2074 for(i=BOARD_HEIGHT-1; i>=0; i--) {
2075 for(j=0; j<BOARD_WIDTH; j++)
2076 fprintf(debugFP, "%3d", (int) board[i][j]);
2077 fprintf(debugFP, "\n");
2083 } else if(pieceDefs && closure->count > 1) { // [HGM] gen: move is ambiguous under engine-defined rules
2084 DisambiguateClosure spare = *closure;
2085 pieceDefs = FALSE; spare.count = 0; // See if the (erroneous) built-in rules would resolve that
2086 GenLegal(board, flags, DisambiguateCallback, (VOIDSTAR) &spare, closure->pieceIn);
2087 if(spare.count == 1) *closure = spare; // It does, so use those in stead (game from file saved before gen patch?)
2091 if (c == 'x') c = NULLCHAR; // get rid of any 'x' (which should never happen?)
2092 if(gameInfo.variant == VariantSChess && c && c != '=' && closure->piece != WhitePawn && closure->piece != BlackPawn) {
2093 if(closure->piece < BlackPawn) { // white
2094 if(closure->rf != 0) closure->kind = IllegalMove; // must be on back rank
2095 if(!(board[VIRGIN][closure->ff] & VIRGIN_W)) closure->kind = IllegalMove; // non-virgin
2096 if(board[PieceToNumber(CharToPiece(ToUpper(c)))][BOARD_WIDTH-2] == 0) closure->kind = ImpossibleMove;// must be in stock
2097 if(closure->kind == WhiteHSideCastleFR && (closure->ff == BOARD_RGHT-2 || closure->ff == BOARD_RGHT-3)) closure->kind = ImpossibleMove;
2098 if(closure->kind == WhiteASideCastleFR && (closure->ff == BOARD_LEFT+2 || closure->ff == BOARD_LEFT+3)) closure->kind = ImpossibleMove;
2100 if(closure->rf != BOARD_HEIGHT-1) closure->kind = IllegalMove;
2101 if(!(board[VIRGIN][closure->ff] & VIRGIN_B)) closure->kind = IllegalMove; // non-virgin
2102 if(board[BOARD_HEIGHT-1-PieceToNumber(CharToPiece(ToLower(c)))][1] == 0) closure->kind = ImpossibleMove;
2103 if(closure->kind == BlackHSideCastleFR && (closure->ff == BOARD_RGHT-2 || closure->ff == BOARD_RGHT-3)) closure->kind = ImpossibleMove;
2104 if(closure->kind == BlackASideCastleFR && (closure->ff == BOARD_LEFT+2 || closure->ff == BOARD_LEFT+3)) closure->kind = ImpossibleMove;
2107 if(gameInfo.variant == VariantChu) {
2108 if(c == '+') closure->kind = (flags & F_WHITE_ON_MOVE ? WhitePromotion : BlackPromotion); // for now, accept any
2110 if(gameInfo.variant == VariantShogi) {
2111 /* [HGM] Shogi promotions. On input, '=' means defer, '+' promote. Afterwards, c is set to '+' for promotions, NULL other */
2112 if(closure->rfIn != DROP_RANK && closure->kind == NormalMove) {
2113 ChessSquare piece = closure->piece;
2114 int zone = BOARD_HEIGHT/3 + (BOARD_HEIGHT == 8);
2115 if (c == 'd' && (piece == WhiteRook || piece == BlackRook) ||
2116 c == 'h' && (piece == WhiteBishop || piece == BlackBishop) ||
2117 c == 'g' && (piece <= WhiteFerz || piece <= BlackFerz && piece >= BlackPawn) )
2118 c = '+'; // allowed ICS notations
2119 if(c != NULLCHAR && c != '+' && c != '=') closure->kind = IllegalMove; // otherwise specifying a piece is illegal
2120 else if(flags & F_WHITE_ON_MOVE) {
2121 if( (int) piece < (int) WhiteWazir &&
2122 (closure->rf >= BOARD_HEIGHT-zone || closure->rt >= BOARD_HEIGHT-zone) ) {
2123 if( (piece == WhitePawn || piece == WhiteQueen) && closure->rt > BOARD_HEIGHT-2 ||
2124 piece == WhiteKnight && closure->rt > BOARD_HEIGHT-3) /* promotion mandatory */
2125 closure->kind = c == '=' ? IllegalMove : WhitePromotion;
2126 else /* promotion optional, default is defer */
2127 closure->kind = c == '+' ? WhitePromotion : WhiteNonPromotion;
2128 } else closure->kind = c == '+' ? IllegalMove : NormalMove;
2130 if( (int) piece < (int) BlackWazir && (closure->rf < zone || closure->rt < zone) ) {
2131 if( (piece == BlackPawn || piece == BlackQueen) && closure->rt < 1 ||
2132 piece == BlackKnight && closure->rt < 2 ) /* promotion obligatory */
2133 closure->kind = c == '=' ? IllegalMove : BlackPromotion;
2134 else /* promotion optional, default is defer */
2135 closure->kind = c == '+' ? BlackPromotion : BlackNonPromotion;
2136 } else closure->kind = c == '+' ? IllegalMove : NormalMove;
2139 if(closure->kind == WhitePromotion || closure->kind == BlackPromotion) c = '+'; else
2140 if(closure->kind == WhiteNonPromotion || closure->kind == BlackNonPromotion) c = '=';
2142 if (closure->kind == WhitePromotion || closure->kind == BlackPromotion) {
2143 if(c == NULLCHAR) { // missing promoChar on mandatory promotion; use default for variant
2144 if(gameInfo.variant == VariantShatranj || gameInfo.variant == VariantCourier ||
2145 gameInfo.variant == VariantMakruk)
2146 c = PieceToChar(BlackFerz);
2147 else if(gameInfo.variant == VariantASEAN)
2148 c = PieceToChar(BlackRook);
2149 else if(gameInfo.variant == VariantGreat)
2150 c = PieceToChar(BlackMan);
2151 else if(gameInfo.variant == VariantGrand)
2152 closure->kind = closure->rt != 0 && closure->rt != BOARD_HEIGHT-1 ? NormalMove : AmbiguousMove; // no default in Grand Chess
2154 c = PieceToChar(BlackQueen);
2155 } else if(c == '=') closure->kind = IllegalMove; // no deferral outside Shogi
2156 else if(c == 'l' && gameInfo.variant == VariantChuChess && HasLion(board, flags)) closure->kind = IllegalMove;
2157 } else if (c == '+') { // '+' outside shogi, check if pieceToCharTable enabled it
2158 ChessSquare p = closure->piece;
2159 if(p > WhiteMan && p < BlackPawn || p > BlackMan || PieceToChar(PROMOTED(p)) != '+')
2160 closure->kind = ImpossibleMove; // used on non-promotable piece
2161 else if(gameInfo.variant == VariantChuChess && HasLion(board, flags)) closure->kind = IllegalMove;
2162 } else if (c != NULLCHAR) closure->kind = IllegalMove;
2164 closure->promoChar = ToLower(c); // this can be NULLCHAR! Note we keep original promoChar even if illegal.
2165 if(c != '+' && c != '=' && c != NULLCHAR && CharToPiece(flags & F_WHITE_ON_MOVE ? ToUpper(c) : ToLower(c)) == EmptySquare)
2166 closure->kind = ImpossibleMove; // but we cannot handle non-existing piece types!
2167 if (closure->count > 1) {
2168 closure->kind = AmbiguousMove;
2171 /* Note: If more than one illegal move matches, but no legal
2172 moves, we return IllegalMove, not AmbiguousMove. Caller
2173 can look at closure->count to detect this.
2175 closure->kind = IllegalMove;
2189 } CoordsToAlgebraicClosure;
2191 extern void CoordsToAlgebraicCallback P((Board board, int flags,
2192 ChessMove kind, int rf, int ff,
2193 int rt, int ft, VOIDSTAR closure));
2196 CoordsToAlgebraicCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
2198 register CoordsToAlgebraicClosure *cl =
2199 (CoordsToAlgebraicClosure *) closure;
2201 if ((rt == cl->rt && ft == cl->ft || rt == rf && ft == ff) && // [HGM] null move matches any toSquare
2202 (board[rf][ff] == cl->piece
2203 || PieceToChar(board[rf][ff]) == '~' &&
2204 (ChessSquare) (DEMOTED(board[rf][ff])) == cl->piece)
2208 cl->kind = kind; /* this is the move we want */
2210 cl->file++; /* need file to rule out this move */
2214 cl->rank++; /* need rank to rule out this move */
2216 cl->either++; /* rank or file will rule out this move */
2222 /* Convert coordinates to normal algebraic notation.
2223 promoChar must be NULLCHAR or 'x' if not a promotion.
2226 CoordsToAlgebraic (Board board, int flags, int rf, int ff, int rt, int ft, int promoChar, char out[MOVE_LEN])
2230 char *outp = out, c, capture;
2231 CoordsToAlgebraicClosure cl;
2233 if (rf == DROP_RANK) {
2234 if(ff == EmptySquare) { strncpy(outp, "--",3); return NormalMove; } // [HGM] pass
2235 /* Bughouse piece drop */
2236 *outp++ = ToUpper(PieceToChar((ChessSquare) ff));
2241 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2243 return (flags & F_WHITE_ON_MOVE) ? WhiteDrop : BlackDrop;
2246 if (promoChar == 'x') promoChar = NULLCHAR;
2247 piece = board[rf][ff];
2248 if(PieceToChar(piece)=='~') piece = (ChessSquare)(DEMOTED(piece));
2253 kind = LegalityTest(board, flags, rf, ff, rt, ft, promoChar);
2254 if (kind == IllegalMove && !(flags&F_IGNORE_CHECK)) {
2255 /* Keep short notation if move is illegal only because it
2256 leaves the player in check, but still return IllegalMove */
2257 kind = LegalityTest(board, flags|F_IGNORE_CHECK, rf, ff, rt, ft, promoChar);
2258 if (kind == IllegalMove) break;
2263 capture = board[rt][ft] != EmptySquare || kind == WhiteCapturesEnPassant || kind == BlackCapturesEnPassant;
2264 if (ff == ft && !capture) { /* [HGM] Xiangqi has straight noncapts! */
2265 /* Non-capture; use style "e5" */
2268 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2270 /* Capture; use style "exd5" */
2272 *outp++ = 'x'; /* [HGM] Xiangqi has sideway noncaptures across river! */
2276 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2278 /* Use promotion suffix style "=Q" */
2280 if (promoChar != NULLCHAR) {
2281 if(IS_SHOGI(gameInfo.variant)) {
2282 /* [HGM] ... but not in Shogi! */
2283 *outp++ = promoChar == '=' ? '=' : '+';
2286 *outp++ = ToUpper(promoChar);
2295 /* Fabien moved code: FRC castling first (if KxR), wild castling second */
2296 /* Code added by Tord: FRC castling. */
2297 if((piece == WhiteKing && board[rt][ft] == WhiteRook) ||
2298 (piece == BlackKing && board[rt][ft] == BlackRook)) {
2300 safeStrCpy(out, "O-O", MOVE_LEN);
2302 safeStrCpy(out, "O-O-O", MOVE_LEN);
2303 return LegalityTest(board, flags, rf, ff, rt, ft, promoChar);
2305 /* End of code added by Tord */
2306 /* Test for castling or ICS wild castling */
2307 /* Use style "O-O" (oh-oh) for PGN compatibility */
2308 else if (rf == rt &&
2309 rf == ((piece == WhiteKing) ? 0 : BOARD_HEIGHT-1) &&
2310 (ft - ff > 1 || ff - ft > 1) && // No castling if legal King move (on narrow boards!)
2311 ((ff == BOARD_WIDTH>>1 && (ft == BOARD_LEFT+2 || ft == BOARD_RGHT-2)) ||
2312 (ff == (BOARD_WIDTH-1)>>1 && (ft == BOARD_LEFT+1 || ft == BOARD_RGHT-3)))) {
2313 if(ft==BOARD_LEFT+1 || ft==BOARD_RGHT-2)
2314 snprintf(out, MOVE_LEN, "O-O%c%c", promoChar ? '/' : 0, ToUpper(promoChar));
2316 snprintf(out, MOVE_LEN, "O-O-O%c%c", promoChar ? '/' : 0, ToUpper(promoChar));
2318 /* This notation is always unambiguous, unless there are
2319 kings on both the d and e files, with "wild castling"
2320 possible for the king on the d file and normal castling
2321 possible for the other. ICS rules for wild 9
2322 effectively make castling illegal for either king in
2323 this situation. So I am not going to worry about it;
2324 I'll just generate an ambiguous O-O in this case.
2326 return LegalityTest(board, flags, rf, ff, rt, ft, promoChar);
2329 /* else fall through */
2334 cl.rt = rFilter = rt; // [HGM] speed: filter on to-square
2335 cl.ft = fFilter = ft;
2337 cl.kind = IllegalMove;
2338 cl.rank = cl.file = cl.either = 0;
2339 c = PieceToChar(piece) ;
2340 GenLegal(board, flags, CoordsToAlgebraicCallback, (VOIDSTAR) &cl, c!='~' ? piece : (DEMOTED(piece))); // [HGM] speed
2342 if (cl.kind == IllegalMove && !(flags&F_IGNORE_CHECK)) {
2343 /* Generate pretty moves for moving into check, but
2344 still return IllegalMove.
2346 GenLegal(board, flags|F_IGNORE_CHECK, CoordsToAlgebraicCallback, (VOIDSTAR) &cl, c!='~' ? piece : (DEMOTED(piece)));
2347 if (cl.kind == IllegalMove) break;
2348 cl.kind = IllegalMove;
2351 /* Style is "Nf3" or "Nxf7" if this is unambiguous,
2352 else "Ngf3" or "Ngxf7",
2353 else "N1f3" or "N5xf7",
2354 else "Ng1f3" or "Ng5xf7".
2356 if( c == '~' || c == '+') {
2357 /* [HGM] print nonexistent piece as its demoted version */
2358 piece = (ChessSquare) (CHUDEMOTED(piece));
2360 if(c=='+') *outp++ = c;
2361 *outp++ = ToUpper(PieceToChar(piece));
2362 if(*outp = PieceSuffix(piece)) outp++;
2364 if (cl.file || (cl.either && !cl.rank)) {
2370 else { *outp++ = (rf+ONE-'0')/10 + '0';*outp++ = (rf+ONE-'0')%10 + '0'; }
2373 if(board[rt][ft] != EmptySquare)
2379 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2380 if (IS_SHOGI(gameInfo.variant)) {
2381 /* [HGM] in Shogi non-pawns can promote */
2382 *outp++ = promoChar; // Don't bother to correct move type, return value is never used!
2384 else if (gameInfo.variant == VariantChuChess && promoChar ||
2385 gameInfo.variant != VariantSuper && promoChar &&
2386 (piece == WhiteLance || piece == BlackLance) ) { // Lance sometimes represents Pawn
2388 *outp++ = ToUpper(promoChar);
2390 else if (gameInfo.variant == VariantSChess && promoChar) { // and in S-Chess we have gating
2392 *outp++ = ToUpper(promoChar);
2398 /* Moving a nonexistent piece */
2402 /* Not a legal move, even ignoring check.
2403 If there was a piece on the from square,
2404 use style "Ng1g3" or "Ng1xe8";
2405 if there was a pawn or nothing (!),
2406 use style "g1g3" or "g1xe8". Use "x"
2407 if a piece was on the to square, even
2408 a piece of the same color.
2412 if (piece != EmptySquare && piece != WhitePawn && piece != BlackPawn) {
2414 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<=BOARD_RGHT; f++)
2415 c += (board[r][f] == piece); // count on-board pieces of given type
2416 *outp++ = ToUpper(PieceToChar(piece));
2418 if(c != 1) { // [HGM] but if there is only one piece of the mentioned type, no from-square, thank you!
2422 else { *outp++ = (rf+ONE-'0')/10 + '0';*outp++ = (rf+ONE-'0')%10 + '0'; }
2424 if (board[rt][ft] != EmptySquare) *outp++ = 'x';
2428 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2429 /* Use promotion suffix style "=Q" */
2430 if (promoChar != NULLCHAR && promoChar != 'x') {
2432 *outp++ = ToUpper(promoChar);
2439 // [HGM] XQ: the following code serves to detect perpetual chasing (Asian rules)
2448 // I guess the following variables logically belong in the closure too, but I was too lazy and used globals
2450 int preyStackPointer, chaseStackPointer;
2453 unsigned char rf, ff, rt, ft;
2457 unsigned char rank, file;
2463 // there are three new callbacks for use with GenLegal: for adding captures, deleting them, and finding a recapture
2465 extern void AtacksCallback P((Board board, int flags, ChessMove kind,
2466 int rf, int ff, int rt, int ft,
2470 AttacksCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
2471 { // For adding captures that can lead to chase indictment to the chaseStack
2472 if(board[rt][ft] == EmptySquare) return; // non-capture
2473 if(board[rt][ft] == WhitePawn && rt < BOARD_HEIGHT/2) return; // Pawn before river can be chased
2474 if(board[rt][ft] == BlackPawn && rt >= BOARD_HEIGHT/2) return; // Pawn before river can be chased
2475 if(board[rf][ff] == WhitePawn || board[rf][ff] == BlackPawn) return; // Pawns are allowed to chase
2476 if(board[rf][ff] == WhiteWazir || board[rf][ff] == BlackWazir) return; // King is allowed to chase
2477 // move cannot be excluded from being a chase trivially (based on attacker and victim); save it on chaseStack
2478 chaseStack[chaseStackPointer].rf = rf;
2479 chaseStack[chaseStackPointer].ff = ff;
2480 chaseStack[chaseStackPointer].rt = rt;
2481 chaseStack[chaseStackPointer].ft = ft;
2482 chaseStackPointer++;
2485 extern void ExistingAtacksCallback P((Board board, int flags, ChessMove kind,
2486 int rf, int ff, int rt, int ft,
2490 ExistingAttacksCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
2491 { // for removing pre-exsting captures from the chaseStack, to be left with newly created ones
2493 register ChaseClosure *cl = (ChaseClosure *) closure; //closure tells us the move played in the repeat loop
2495 if(board[rt][ft] == EmptySquare) return; // no capture
2496 if(rf == cl->rf && ff == cl->ff) { // attacks with same piece from new position are not considered new
2497 rf = cl->rt; ff = cl->ft; // doctor their fromSquare so they will be recognized in chaseStack
2499 // search move in chaseStack, and delete it if it occurred there (as we know now it is not a new capture)
2500 for(i=0; i<chaseStackPointer; i++) {
2501 if(chaseStack[i].rf == rf && chaseStack[i].ff == ff &&
2502 chaseStack[i].rt == rt && chaseStack[i].ft == ft ) {
2503 // move found on chaseStack, delete it by overwriting with move popped from top of chaseStack
2504 chaseStack[i] = chaseStack[--chaseStackPointer];
2510 extern void ProtectedCallback P((Board board, int flags, ChessMove kind,
2511 int rf, int ff, int rt, int ft,
2515 ProtectedCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
2516 { // for determining if a piece (given through the closure) is protected
2517 register ChaseClosure *cl = (ChaseClosure *) closure; // closure tells us where to recapture
2519 if(rt == cl->rt && ft == cl->ft) cl->recaptures++; // count legal recaptures to this square
2520 if(appData.debugMode && board[rt][ft] != EmptySquare)
2521 fprintf(debugFP, "try %c%c%c%c=%d\n", ff+AAA, rf+ONE,ft+AAA, rt+ONE, cl->recaptures);
2524 extern char moveList[MAX_MOVES][MOVE_LEN];
2527 PerpetualChase (int first, int last)
2528 { // this routine detects if the side to move in the 'first' position is perpetually chasing (when not checking)
2531 ChessSquare captured;
2533 preyStackPointer = 0; // clear stack of chased pieces
2534 for(i=first; i<last; i+=2) { // for all positions with same side to move
2535 if(appData.debugMode) fprintf(debugFP, "judge position %i\n", i);
2536 chaseStackPointer = 0; // clear stack that is going to hold possible chases
2537 // determine all captures possible after the move, and put them on chaseStack
2538 GenLegal(boards[i+1], PosFlags(i), AttacksCallback, &cl, EmptySquare);
2539 if(appData.debugMode) { int n;
2540 for(n=0; n<chaseStackPointer; n++)
2541 fprintf(debugFP, "%c%c%c%c ", chaseStack[n].ff+AAA, chaseStack[n].rf+ONE,
2542 chaseStack[n].ft+AAA, chaseStack[n].rt+ONE);
2543 fprintf(debugFP, ": all capts\n");
2545 // determine all captures possible before the move, and delete them from chaseStack
2546 cl.rf = moveList[i][1]-ONE; // prepare closure to pass move that led from i to i+1
2547 cl.ff = moveList[i][0]-AAA+BOARD_LEFT;
2548 cl.rt = moveList[i][3]-ONE;
2549 cl.ft = moveList[i][2]-AAA+BOARD_LEFT;
2550 CopyBoard(xqCheckers, nullBoard); xqCheckers[EP_STATUS] = 1; // giant kludge to make GenLegal ignore pre-existing checks
2551 GenLegal(boards[i], PosFlags(i), ExistingAttacksCallback, &cl, EmptySquare);
2552 xqCheckers[EP_STATUS] = 0; // disable the generation of quasi-legal moves again
2553 if(appData.debugMode) { int n;
2554 for(n=0; n<chaseStackPointer; n++)
2555 fprintf(debugFP, "%c%c%c%c ", chaseStack[n].ff+AAA, chaseStack[n].rf+ONE,
2556 chaseStack[n].ft+AAA, chaseStack[n].rt+ONE);
2557 fprintf(debugFP, ": new capts after %c%c%c%c\n", cl.ff+AAA, cl.rf+ONE, cl.ft+AAA, cl.rt+ONE);
2559 // chaseSack now contains all captures made possible by the move
2560 for(j=0; j<chaseStackPointer; j++) { // run through chaseStack to identify true chases
2561 int attacker = (int)boards[i+1][chaseStack[j].rf][chaseStack[j].ff];
2562 int victim = (int)boards[i+1][chaseStack[j].rt][chaseStack[j].ft];
2564 if(attacker >= (int) BlackPawn) attacker = BLACK_TO_WHITE attacker; // convert to white, as piecee type
2565 if(victim >= (int) BlackPawn) victim = BLACK_TO_WHITE victim;
2567 if((attacker == WhiteKnight || attacker == WhiteCannon) && victim == WhiteRook)
2568 continue; // C or H attack on R is always chase; leave on chaseStack
2570 if(attacker == victim) {
2571 if(LegalityTest(boards[i+1], PosFlags(i+1), chaseStack[j].rt,
2572 chaseStack[j].ft, chaseStack[j].rf, chaseStack[j].ff, NULLCHAR) == NormalMove) {
2573 // we can capture back with equal piece, so this is no chase but a sacrifice
2574 chaseStack[j] = chaseStack[--chaseStackPointer]; // delete the capture from the chaseStack
2575 j--; /* ! */ continue;
2580 // the attack is on a lower piece, or on a pinned or blocked equal one
2581 CopyBoard(xqCheckers, nullBoard); xqCheckers[EP_STATUS] = 1;
2582 CheckTest(boards[i+1], PosFlags(i+1), -1, -1, -1, -1, FALSE); // if we deliver check with our move, the checkers get marked
2583 // test if the victim is protected by a true protector. First make the capture.
2584 captured = boards[i+1][chaseStack[j].rt][chaseStack[j].ft];
2585 boards[i+1][chaseStack[j].rt][chaseStack[j].ft] = boards[i+1][chaseStack[j].rf][chaseStack[j].ff];
2586 boards[i+1][chaseStack[j].rf][chaseStack[j].ff] = EmptySquare;
2587 // Then test if the opponent can recapture
2588 cl.recaptures = 0; // prepare closure to pass recapture square and count moves to it
2589 cl.rt = chaseStack[j].rt;
2590 cl.ft = chaseStack[j].ft;
2591 if(appData.debugMode) {
2592 fprintf(debugFP, "test if we can recapture %c%c\n", cl.ft+AAA, cl.rt+ONE);
2594 xqCheckers[EP_STATUS] = 2; // causes GenLegal to ignore the checks we delivered with the move, in real life evaded before we captured
2595 GenLegal(boards[i+1], PosFlags(i+1), ProtectedCallback, &cl, EmptySquare); // try all moves
2596 xqCheckers[EP_STATUS] = 0; // disable quasi-legal moves again
2597 // unmake the capture
2598 boards[i+1][chaseStack[j].rf][chaseStack[j].ff] = boards[i+1][chaseStack[j].rt][chaseStack[j].ft];
2599 boards[i+1][chaseStack[j].rt][chaseStack[j].ft] = captured;
2600 // if a recapture was found, piece is protected, and we are not chasing it.
2601 if(cl.recaptures) { // attacked piece was defended by true protector, no chase
2602 chaseStack[j] = chaseStack[--chaseStackPointer]; // so delete from chaseStack
2606 // chaseStack now contains all moves that chased
2607 if(appData.debugMode) { int n;
2608 for(n=0; n<chaseStackPointer; n++)
2609 fprintf(debugFP, "%c%c%c%c ", chaseStack[n].ff+AAA, chaseStack[n].rf+ONE,
2610 chaseStack[n].ft+AAA, chaseStack[n].rt+ONE);
2611 fprintf(debugFP, ": chases\n");
2613 if(i == first) { // copy all people chased by first move of repeat cycle to preyStack
2614 for(j=0; j<chaseStackPointer; j++) {
2615 preyStack[j].rank = chaseStack[j].rt;
2616 preyStack[j].file = chaseStack[j].ft;
2618 preyStackPointer = chaseStackPointer;
2621 for(j=0; j<chaseStackPointer; j++) {
2622 for(k=0; k<preyStackPointer; k++) {
2623 // search the victim of each chase move on the preyStack (first occurrence)
2624 if(chaseStack[j].ft == preyStack[k].file && chaseStack[j].rt == preyStack[k].rank ) {
2625 if(k < tail) break; // piece was already identified as still being chased
2626 preyStack[preyStackPointer] = preyStack[tail]; // move chased piece to bottom part of preyStack
2627 preyStack[tail] = preyStack[k]; // by swapping
2628 preyStack[k] = preyStack[preyStackPointer];
2634 preyStackPointer = tail; // keep bottom part of preyStack, popping pieces unchased on move i.
2635 if(appData.debugMode) { int n;
2636 for(n=0; n<preyStackPointer; n++)
2637 fprintf(debugFP, "%c%c ", preyStack[n].file+AAA, preyStack[n].rank+ONE);
2638 fprintf(debugFP, "always chased upto ply %d\n", i);
2640 // now adjust the location of the chased pieces according to opponent move
2641 for(j=0; j<preyStackPointer; j++) {
2642 if(preyStack[j].rank == moveList[i+1][1]-ONE &&
2643 preyStack[j].file == moveList[i+1][0]-AAA+BOARD_LEFT) {
2644 preyStack[j].rank = moveList[i+1][3]-ONE;
2645 preyStack[j].file = moveList[i+1][2]-AAA+BOARD_LEFT;
2650 return preyStackPointer ? 256*(preyStack[preyStackPointer].file - BOARD_LEFT + AAA) + (preyStack[preyStackPointer].rank + ONE)
2651 : 0; // if any piece was left on preyStack, it has been perpetually chased,and we return the