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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23 * software without specific, written prior permission.
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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);
75 char *pieceDesc[EmptySquare];
76 char *defaultDesc[EmptySquare] = {
77 "fmWfceFifmnD", "N", "B", "R", "Q",
78 "F", "A", "BN", "RN", "W", "K",
79 "mRcpR", "N0", "BW", "RF", "gQ",
80 "", "", "QN", "", "N", "",
82 "", "", "", "", "", "",
84 "", "", "", "", "", "K"
88 WhitePiece (ChessSquare piece)
90 return (int) piece >= (int) WhitePawn && (int) piece < (int) BlackPawn;
94 BlackPiece (ChessSquare piece)
96 return (int) piece >= (int) BlackPawn && (int) piece < (int) EmptySquare;
101 SameColor (ChessSquare piece1, ChessSquare piece2)
103 return ((int) piece1 >= (int) WhitePawn && /* [HGM] can be > King ! */
104 (int) piece1 < (int) BlackPawn &&
105 (int) piece2 >= (int) WhitePawn &&
106 (int) piece2 < (int) BlackPawn)
107 || ((int) piece1 >= (int) BlackPawn &&
108 (int) piece1 < (int) EmptySquare &&
109 (int) piece2 >= (int) BlackPawn &&
110 (int) piece2 < (int) EmptySquare);
113 #define SameColor(piece1, piece2) (piece1 < EmptySquare && piece2 < EmptySquare && (piece1 < BlackPawn) == (piece2 < BlackPawn) || piece1 == DarkSquare || piece2 == DarkSquare)
116 unsigned char pieceToChar[EmptySquare+1] = {
117 'P', 'N', 'B', 'R', 'Q', 'F', 'E', 'A', 'C', 'W', 'M',
118 'O', 'H', 'I', 'J', 'G', 'D', 'V', 'L', 'S', 'U', 'K',
119 'p', 'n', 'b', 'r', 'q', 'f', 'e', 'a', 'c', 'w', 'm',
120 'o', 'h', 'i', 'j', 'g', 'd', 'v', 'l', 's', 'u', 'k',
122 unsigned char pieceNickName[EmptySquare];
123 int promoPartner[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 > 0 && dx == 0 && dy == 0) { // castling indicated by O + number
380 mode |= 1024; dy = 1;
382 if(expo < 0) expo = 1; // use 1 for default
384 if(!(mode & 15)) mode |= his + 4; // no mode spec, use default = mc
386 strncpy(buf, cont, 80); cont = buf; // copy next leg(s), so we can modify
387 atom = buf; while(islower(*atom)) atom++; // skip to atom
388 if(mode & 32) mode ^= 256 + 32; // in non-final legs 'p' means 'pass through'
389 if(mode & 64 + 512) {
390 mode |= 256; // and 'g' too, but converts leaper <-> slider
391 if(mode & 512) mode ^= 0x304; // and 'y' is m-like 'g'
392 *atom = upgrade[*atom-'A']; // replace atom, BRQ <-> FWK
393 atom[1] = atom[2] = '\0'; // make sure any old range is stripped off
394 if(expo == 1) atom[1] = '0'; // turn other leapers into riders
396 if(!(mode & 0x30F)) mode |= 4; // and default of this leg = m
398 if(dy == 1) skip = jump - 1, jump = 1; // on W & F atoms 'j' = skip first square
400 for(dir=0, bit=1; dir<8; dir++, bit += bit) { // loop over directions
401 int i = expo, j = skip, hop = mode, vx, vy, loop = 0;
402 if(!(bit & dirSet)) continue; // does not move in this direction
403 if(dy != 1 || mode & 1024) j = 0; //
404 vx = dx*rot[dir][0] + dy*rot[dir][1]; // rotate step vector
405 vy = dx*rot[dir][2] + dy*rot[dir][3];
406 if(tx < 0) x = f, y = r; // start square
407 else x = tx, y = ty; // from previous to-square if continuation
409 x += vx; y += vy; // step to next square
410 if(y < 0 || y >= BOARD_HEIGHT) break; // vertically off-board: always done
411 if(x < BOARD_LEFT) { if(mode & 128) x += BOARD_RGHT - BOARD_LEFT, loop++; else break; }
412 if(x >= BOARD_RGHT) { if(mode & 128) x -= BOARD_RGHT - BOARD_LEFT, loop++; else break; }
413 if(j) { j--; continue; } // skip irrespective of occupation
414 if(board[y][x] == DarkSquare) break; // black squares are supposed to be off board
415 if(!jump && board[y - vy + vy/2][x - vx + vx/2] != EmptySquare) break; // blocked
416 if(jump > 1 && board[y - vy + vy/2][x - vx + vx/2] == EmptySquare) break; // no hop
417 if(x == f && y == r && !loop) occup = 4; else // start square counts as empty (if not around cylinder!)
418 if(board[y][x] < BlackPawn) occup = 0x101; else
419 if(board[y][x] < EmptySquare) occup = 0x102; else
421 if(cont) { // non-final leg
422 if(mode&16 && his&occup) occup &= 3;// suppress hopping foe in t-mode
423 if(occup & mode) { // valid intermediate square, do continuation
424 char origAtom = *atom;
425 if(!(bit & all)) *atom = rotate[*atom - 'A']; // orth-diag interconversion to make direction valid
426 if(occup & mode & 0x104) // no side effects, merge legs to one move
427 MovesFromString(board, flags, f, r, x, y, dir, cont, cb, cl);
428 if(occup & mode & 3 && (killX < 0 || killX == x && killY == y)) { // destructive first leg
430 MovesFromString(board, flags, f, r, x, y, dir, cont, &OK, &cnt); // count possible continuations
431 if(cnt) { // and if there are
432 if(killX < 0) cb(board, flags, FirstLeg, r, f, y, x, cl); // then generate their first leg
434 MovesFromString(board, flags, f, r, x, y, dir, cont, cb, cl);
438 *atom = origAtom; // undo any interconversion
440 if(occup != 4) break; // occupied squares always terminate the leg
443 if(hop & 32+64) { if(occup != 4) { if(hop & 64 && i != 1) i = 2; hop &= 31; } continue; } // hopper
445 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)
446 cb(board, flags, mine == 1 ? WhiteCapturesEnPassant : BlackCapturesEnPassant, r, f, y, x, cl);
448 if(mode & 1024) { // castling
449 i = 2; // kludge to elongate move indefinitely
450 if(occup == 4) continue; // skip empty squares
451 if((x == BOARD_LEFT + skip || x > BOARD_LEFT + skip && vx < 0 && board[y][x-1-skip] == DarkSquare)
452 && board[y][x] == initialPosition[y][x]) { // reached initial corner piece
453 if(pc != WhiteKing && pc != BlackKing || expo == 1) { // non-royal castling (to be entered as two-leg move via 'Rook')
454 if(killX < 0) cb(board, flags, FirstLeg, r, f, y, x, cl); if(killX < f)
455 legNr <<= 1, cb(board, flags, NormalMove, r, f, y, f - expo, cl), legNr >>= 1;
457 cb(board, flags, mine == 1 ? WhiteQueenSideCastle : BlackQueenSideCastle, r, f, y, f - expo, cl);
459 if((x == BOARD_RGHT-1-skip || x < BOARD_RGHT-1-skip && vx > 0 && board[y][x+1+skip] == DarkSquare)
460 && board[y][x] == initialPosition[y][x]) {
461 if(pc != WhiteKing && pc != BlackKing || expo == 1) {
462 if(killX < 0) cb(board, flags, FirstLeg, r, f, y, x, cl); if(killX > f)
463 legNr <<= 1, cb(board, flags, NormalMove, r, f, y, f + expo, cl), legNr >>= 1;
465 cb(board, flags, mine == 1 ? WhiteKingSideCastle : BlackKingSideCastle, r, f, y, f + expo, cl);
469 if(mode & 16 && (board[y][x] == WhiteKing || board[y][x] == BlackKing)) break; // tame piece, cannot capture royal
470 if(occup & mode) cb(board, flags, y == promoRank ? promo : NormalMove, r, f, y, x, cl); // allowed, generate
471 if(occup != 4) break; // not valid transit square
474 dx = dy; dirSet = ds2; // prepare for diagonal moves of K,Q
475 } while(retry-- && ds2); // and start doing them
476 if(tx >= 0) break; // don't do other atoms in continuation legs
480 // [HGM] move generation now based on hierarchy of subroutines for rays and combinations of rays
483 SlideForward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
488 if (rt >= BOARD_HEIGHT) break;
489 if (SameColor(board[rf][ff], board[rt][ft])) break;
490 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
491 if (board[rt][ft] != EmptySquare) break;
496 SlideBackward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
502 if (SameColor(board[rf][ff], board[rt][ft])) break;
503 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
504 if (board[rt][ft] != EmptySquare) break;
509 SlideVertical (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
511 SlideForward(board, flags, rf, ff, callback, closure);
512 SlideBackward(board, flags, rf, ff, callback, closure);
516 SlideSideways (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
518 int i, s, rt = rf, ft;
519 for(s = -1; s <= 1; s+= 2) {
522 if (ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
523 if (SameColor(board[rf][ff], board[rt][ft])) break;
524 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
525 if (board[rt][ft] != EmptySquare) break;
531 SlideDiagForward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
534 for(s = -1; s <= 1; s+= 2) {
538 if (rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
539 if (SameColor(board[rf][ff], board[rt][ft])) break;
540 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
541 if (board[rt][ft] != EmptySquare) break;
547 SlideDiagBackward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
550 for(s = -1; s <= 1; s+= 2) {
554 if (rt < 0 || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
555 if (SameColor(board[rf][ff], board[rt][ft])) break;
556 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
557 if (board[rt][ft] != EmptySquare) break;
563 Rook (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
565 SlideVertical(board, flags, rf, ff, callback, closure);
566 SlideSideways(board, flags, rf, ff, callback, closure);
570 Bishop (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
572 SlideDiagForward(board, flags, rf, ff, callback, closure);
573 SlideDiagBackward(board, flags, rf, ff, callback, closure);
577 Sting (Board board, int flags, int rf, int ff, int dy, int dx, MoveCallback callback, VOIDSTAR closure)
578 { // Lion-like move of Horned Falcon and Souring Eagle
579 int ft = ff + dx, rt = rf + dy;
580 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) return;
582 if (!SameColor(board[rf][ff], board[rt][ft]))
583 callback(board, flags, board[rt][ft] != EmptySquare ? FirstLeg : NormalMove, rf, ff, rt, ft, closure);
586 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) return;
588 if (!SameColor(board[rf][ff], board[rt][ft]))
589 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
590 if (!SameColor(board[rf][ff], board[rf+dy][ff+dx]))
591 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
596 StepForward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
598 int ft = ff, rt = rf + 1;
599 if (rt >= BOARD_HEIGHT) return;
600 if (SameColor(board[rf][ff], board[rt][ft])) return;
601 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
605 StepBackward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
607 int ft = ff, rt = rf - 1;
609 if (SameColor(board[rf][ff], board[rt][ft])) return;
610 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
614 StepSideways (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
618 if (!(rt >= BOARD_HEIGHT || ft >= BOARD_RGHT) && !SameColor(board[rf][ff], board[rt][ft]))
619 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
621 if (!(rt >= BOARD_HEIGHT || ft < BOARD_LEFT) && !SameColor(board[rf][ff], board[rt][ft]))
622 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
626 StepDiagForward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
629 if (rt >= BOARD_HEIGHT) return;
631 if (!(rt >= BOARD_HEIGHT || ft >= BOARD_RGHT) && !SameColor(board[rf][ff], board[rt][ft]))
632 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
634 if (!(rt >= BOARD_HEIGHT || ft < BOARD_LEFT) && !SameColor(board[rf][ff], board[rt][ft]))
635 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
639 StepDiagBackward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
644 if (!(rt < 0 || ft >= BOARD_RGHT) && !SameColor(board[rf][ff], board[rt][ft]))
645 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
647 if (!(rt < 0 || ft < BOARD_LEFT) && !SameColor(board[rf][ff], board[rt][ft]))
648 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
652 StepVertical (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
654 StepForward(board, flags, rf, ff, callback, closure);
655 StepBackward(board, flags, rf, ff, callback, closure);
659 Ferz (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
661 StepDiagForward(board, flags, rf, ff, callback, closure);
662 StepDiagBackward(board, flags, rf, ff, callback, closure);
666 Wazir (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
668 StepVertical(board, flags, rf, ff, callback, closure);
669 StepSideways(board, flags, rf, ff, callback, closure);
673 Knight (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
676 for (i = -1; i <= 1; i += 2)
677 for (j = -1; j <= 1; j += 2)
678 for (s = 1; s <= 2; s++) {
681 if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
682 && ( gameInfo.variant != VariantXiangqi || board[rf+i*(s-1)][ff+j*(2-s)] == EmptySquare)
683 && !SameColor(board[rf][ff], board[rt][ft]))
684 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
688 /* Call callback once for each pseudo-legal move in the given
689 position, except castling moves. A move is pseudo-legal if it is
690 legal, or if it would be legal except that it leaves the king in
691 check. In the arguments, epfile is EP_NONE if the previous move
692 was not a double pawn push, or the file 0..7 if it was, or
693 EP_UNKNOWN if we don't know and want to allow all e.p. captures.
694 Promotion moves generated are to Queen only.
697 GenPseudoLegal (Board board, int flags, MoveCallback callback, VOIDSTAR closure, ChessSquare filter)
698 // speed: only do moves with this piece type
701 int i, j, d, s, fs, rs, rt, ft, m;
702 int epfile = (signed char)board[EP_STATUS]; // [HGM] gamestate: extract ep status from board
703 int promoRank = gameInfo.variant == VariantMakruk || gameInfo.variant == VariantGrand || gameInfo.variant == VariantChuChess ? 3 : 1;
705 for (rf = 0; rf < BOARD_HEIGHT; rf++)
706 for (ff = BOARD_LEFT; ff < BOARD_RGHT; ff++) {
709 if(board[rf][ff] == EmptySquare) continue;
710 if ((flags & F_WHITE_ON_MOVE) != (board[rf][ff] < BlackPawn)) continue; // [HGM] speed: wrong color
711 m = 0; piece = board[rf][ff];
712 if(PieceToChar(piece) == '~')
713 piece = (ChessSquare) ( DEMOTED(piece) );
714 if(filter != EmptySquare && piece != filter) continue;
715 if(pieceDefs && pieceDesc[piece]) { // [HGM] gen: use engine-defined moves
716 MovesFromString(board, flags, ff, rf, -1, -1, 0, pieceDesc[piece], callback, closure);
719 if(IS_SHOGI(gameInfo.variant))
720 piece = (ChessSquare) ( SHOGI piece );
722 switch ((int)piece) {
723 /* case EmptySquare: [HGM] this is nonsense, and conflicts with Shogi cases */
725 /* can't happen ([HGM] except for faries...) */
729 if(gameInfo.variant == VariantXiangqi) {
730 /* [HGM] capture and move straight ahead in Xiangqi */
731 if (rf < BOARD_HEIGHT-1 &&
732 !SameColor(board[rf][ff], board[rf + 1][ff]) ) {
733 callback(board, flags, NormalMove,
734 rf, ff, rf + 1, ff, closure);
736 /* and move sideways when across the river */
737 for (s = -1; s <= 1; s += 2) {
738 if (rf >= BOARD_HEIGHT>>1 &&
739 ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
740 !WhitePiece(board[rf][ff+s]) ) {
741 callback(board, flags, NormalMove,
742 rf, ff, rf, ff+s, closure);
747 if (rf < BOARD_HEIGHT-1 && board[rf + 1][ff] == EmptySquare) {
748 callback(board, flags,
749 rf >= BOARD_HEIGHT-1-promoRank ? WhitePromotion : NormalMove,
750 rf, ff, rf + 1, ff, closure);
752 if (rf <= (BOARD_HEIGHT>>1)-3 && board[rf+1][ff] == EmptySquare && // [HGM] grand: also on 3rd rank on 10-board
753 gameInfo.variant != VariantShatranj && /* [HGM] */
754 gameInfo.variant != VariantCourier && /* [HGM] */
755 board[rf+2][ff] == EmptySquare ) {
756 callback(board, flags, NormalMove,
757 rf, ff, rf+2, ff, closure);
759 for (s = -1; s <= 1; s += 2) {
760 if (rf < BOARD_HEIGHT-1 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
761 ((flags & F_KRIEGSPIEL_CAPTURE) ||
762 BlackPiece(board[rf + 1][ff + s]))) {
763 callback(board, flags,
764 rf >= BOARD_HEIGHT-1-promoRank ? WhitePromotion : NormalMove,
765 rf, ff, rf + 1, ff + s, closure);
767 if (rf >= BOARD_HEIGHT+1>>1) {// [HGM] grand: 4th & 5th rank on 10-board
768 if (ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
769 (epfile == ff + s || epfile == EP_UNKNOWN) && rf < BOARD_HEIGHT-3 &&
770 board[rf][ff + s] == BlackPawn &&
771 board[rf+1][ff + s] == EmptySquare) {
772 callback(board, flags, WhiteCapturesEnPassant,
773 rf, ff, rf+1, ff + s, closure);
780 if(gameInfo.variant == VariantXiangqi) {
781 /* [HGM] capture straight ahead in Xiangqi */
782 if (rf > 0 && !SameColor(board[rf][ff], board[rf - 1][ff]) ) {
783 callback(board, flags, NormalMove,
784 rf, ff, rf - 1, ff, closure);
786 /* and move sideways when across the river */
787 for (s = -1; s <= 1; s += 2) {
788 if (rf < BOARD_HEIGHT>>1 &&
789 ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
790 !BlackPiece(board[rf][ff+s]) ) {
791 callback(board, flags, NormalMove,
792 rf, ff, rf, ff+s, closure);
797 if (rf > 0 && board[rf - 1][ff] == EmptySquare) {
798 callback(board, flags,
799 rf <= promoRank ? BlackPromotion : NormalMove,
800 rf, ff, rf - 1, ff, closure);
802 if (rf >= (BOARD_HEIGHT+1>>1)+2 && board[rf-1][ff] == EmptySquare && // [HGM] grand
803 gameInfo.variant != VariantShatranj && /* [HGM] */
804 gameInfo.variant != VariantCourier && /* [HGM] */
805 board[rf-2][ff] == EmptySquare) {
806 callback(board, flags, NormalMove,
807 rf, ff, rf-2, ff, closure);
809 for (s = -1; s <= 1; s += 2) {
810 if (rf > 0 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
811 ((flags & F_KRIEGSPIEL_CAPTURE) ||
812 WhitePiece(board[rf - 1][ff + s]))) {
813 callback(board, flags,
814 rf <= promoRank ? BlackPromotion : NormalMove,
815 rf, ff, rf - 1, ff + s, closure);
817 if (rf < BOARD_HEIGHT>>1) {
818 if (ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
819 (epfile == ff + s || epfile == EP_UNKNOWN) && rf > 2 &&
820 board[rf][ff + s] == WhitePawn &&
821 board[rf-1][ff + s] == EmptySquare) {
822 callback(board, flags, BlackCapturesEnPassant,
823 rf, ff, rf-1, ff + s, closure);
833 for (i = -1; i <= 1; i += 2)
834 for (j = -1; j <= 1; j += 2)
835 for (s = 1; s <= 2; s++) {
838 if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
839 && ( gameInfo.variant != VariantXiangqi || board[rf+i*(s-1)][ff+j*(2-s)] == EmptySquare)
840 && !SameColor(board[rf][ff], board[rt][ft]))
841 callback(board, flags, NormalMove,
842 rf, ff, rt, ft, closure);
846 case SHOGI WhiteKnight:
847 for (s = -1; s <= 1; s += 2) {
848 if (rf < BOARD_HEIGHT-2 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
849 !SameColor(board[rf][ff], board[rf + 2][ff + s])) {
850 callback(board, flags, NormalMove,
851 rf, ff, rf + 2, ff + s, closure);
856 case SHOGI BlackKnight:
857 for (s = -1; s <= 1; s += 2) {
858 if (rf > 1 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
859 !SameColor(board[rf][ff], board[rf - 2][ff + s])) {
860 callback(board, flags, NormalMove,
861 rf, ff, rf - 2, ff + s, closure);
868 for (d = 0; d <= 1; d++)
869 for (s = -1; s <= 1; s += 2) {
872 rt = rf + (i * s) * d;
873 ft = ff + (i * s) * (1 - d);
874 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
875 if (m == 0 && board[rt][ft] == EmptySquare)
876 callback(board, flags, NormalMove,
877 rf, ff, rt, ft, closure);
878 if (m == 1 && board[rt][ft] != EmptySquare &&
879 !SameColor(board[rf][ff], board[rt][ft]) )
880 callback(board, flags, NormalMove,
881 rf, ff, rt, ft, closure);
882 if (board[rt][ft] != EmptySquare && m++) break;
887 /* Gold General (and all its promoted versions) . First do the */
888 /* diagonal forward steps, then proceed as normal Wazir */
889 case SHOGI (PROMO WhitePawn):
890 if(gameInfo.variant == VariantShogi) goto WhiteGold;
891 case SHOGI (PROMO BlackPawn):
892 if(gameInfo.variant == VariantShogi) goto BlackGold;
893 SlideVertical(board, flags, rf, ff, callback, closure);
896 case SHOGI (PROMO WhiteKnight):
897 if(gameInfo.variant == VariantShogi) goto WhiteGold;
898 case SHOGI BlackDrunk:
899 case SHOGI BlackAlfil:
900 Ferz(board, flags, rf, ff, callback, closure);
901 StepSideways(board, flags, rf, ff, callback, closure);
902 StepBackward(board, flags, rf, ff, callback, closure);
905 case SHOGI (PROMO BlackKnight):
906 if(gameInfo.variant == VariantShogi) goto BlackGold;
907 case SHOGI WhiteDrunk:
908 case SHOGI WhiteAlfil:
909 Ferz(board, flags, rf, ff, callback, closure);
910 StepSideways(board, flags, rf, ff, callback, closure);
911 StepForward(board, flags, rf, ff, callback, closure);
915 case SHOGI WhiteStag:
916 case SHOGI BlackStag:
917 if(gameInfo.variant == VariantShogi) goto BlackGold;
918 SlideVertical(board, flags, rf, ff, callback, closure);
919 Ferz(board, flags, rf, ff, callback, closure);
920 StepSideways(board, flags, rf, ff, callback, closure);
923 case SHOGI (PROMO WhiteQueen):
924 case SHOGI WhiteTokin:
925 case SHOGI WhiteWazir:
927 StepDiagForward(board, flags, rf, ff, callback, closure);
928 Wazir(board, flags, rf, ff, callback, closure);
931 case SHOGI (PROMO BlackQueen):
932 case SHOGI BlackTokin:
933 case SHOGI BlackWazir:
935 StepDiagBackward(board, flags, rf, ff, callback, closure);
936 Wazir(board, flags, rf, ff, callback, closure);
941 Wazir(board, flags, rf, ff, callback, closure);
944 case SHOGI WhiteMarshall:
945 case SHOGI BlackMarshall:
946 Ferz(board, flags, rf, ff, callback, closure);
947 for (d = 0; d <= 1; d++)
948 for (s = -2; s <= 2; s += 4) {
950 ft = ff + s * (1 - d);
951 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) continue;
952 if (!SameColor(board[rf][ff], board[rt][ft]) )
953 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
957 case SHOGI WhiteAngel:
958 case SHOGI BlackAngel:
959 Wazir(board, flags, rf, ff, callback, closure);
963 /* [HGM] support Shatranj pieces */
964 for (rs = -1; rs <= 1; rs += 2)
965 for (fs = -1; fs <= 1; fs += 2) {
968 if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
969 && ( gameInfo.variant != VariantXiangqi ||
970 board[rf+rs][ff+fs] == EmptySquare && (2*rf < BOARD_HEIGHT) == (2*rt < BOARD_HEIGHT) )
972 && !SameColor(board[rf][ff], board[rt][ft]))
973 callback(board, flags, NormalMove,
974 rf, ff, rt, ft, closure);
975 if(gameInfo.variant == VariantShatranj || gameInfo.variant == VariantCourier ||
976 gameInfo.variant == VariantChu || gameInfo.variant == VariantXiangqi) continue; // classical Alfil
977 rt = rf + rs; // in unknown variant we assume Modern Elephant, which can also do one step
979 if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
980 && !SameColor(board[rf][ff], board[rt][ft]))
981 callback(board, flags, NormalMove,
982 rf, ff, rt, ft, closure);
984 if(gameInfo.variant == VariantSpartan)
985 for(fs = -1; fs <= 1; fs += 2) {
987 if (!(ft < BOARD_LEFT || ft >= BOARD_RGHT) && board[rf][ft] == EmptySquare)
988 callback(board, flags, NormalMove, rf, ff, rf, ft, closure);
992 /* Make Dragon-Horse also do Dababba moves outside Shogi, for better disambiguation in variant Fairy */
995 if(gameInfo.variant == VariantChuChess) goto DragonHorse;
996 for (d = 0; d <= 1; d++) // Dababba moves that Rook cannot do
997 for (s = -2; s <= 2; s += 4) {
999 ft = ff + s * (1 - d);
1000 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) continue;
1001 if (SameColor(board[rf][ff], board[rt][ft])) continue;
1002 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
1005 /* Shogi Dragon Horse has to continue with Wazir after Bishop */
1006 case SHOGI WhiteCardinal:
1007 case SHOGI BlackCardinal:
1008 case SHOGI WhitePCardinal:
1009 case SHOGI BlackPCardinal:
1011 Bishop(board, flags, rf, ff, callback, closure);
1012 Wazir(board, flags, rf, ff, callback, closure);
1015 /* Capablanca Archbishop continues as Knight */
1018 Knight(board, flags, rf, ff, callback, closure);
1020 /* Shogi Bishops are ordinary Bishops */
1021 case SHOGI WhiteBishop:
1022 case SHOGI BlackBishop:
1023 case SHOGI WhitePBishop:
1024 case SHOGI BlackPBishop:
1027 Bishop(board, flags, rf, ff, callback, closure);
1030 /* Shogi Lance is unlike anything, and asymmetric at that */
1031 case SHOGI WhiteQueen:
1032 if(gameInfo.variant == VariantChu) goto doQueen;
1036 if (rt >= BOARD_HEIGHT) break;
1037 if (SameColor(board[rf][ff], board[rt][ft])) break;
1038 callback(board, flags, NormalMove,
1039 rf, ff, rt, ft, closure);
1040 if (board[rt][ft] != EmptySquare) break;
1044 case SHOGI BlackQueen:
1045 if(gameInfo.variant == VariantChu) goto doQueen;
1050 if (SameColor(board[rf][ff], board[rt][ft])) break;
1051 callback(board, flags, NormalMove,
1052 rf, ff, rt, ft, closure);
1053 if (board[rt][ft] != EmptySquare) break;
1057 /* Make Dragon-King Dababba & Rook-like outside Shogi, for better disambiguation in variant Fairy */
1060 if(gameInfo.variant == VariantChuChess) goto DragonKing;
1061 for (d = 0; d <= 1; d++) // Dababba moves that Rook cannot do
1062 for (s = -2; s <= 2; s += 4) {
1064 ft = ff + s * (1 - d);
1065 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) continue;
1066 if (board[rf+rt>>1][ff+ft>>1] == EmptySquare && gameInfo.variant != VariantSpartan) continue;
1067 if (SameColor(board[rf][ff], board[rt][ft])) continue;
1068 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
1070 if(gameInfo.variant == VariantSpartan) // in Spartan Chess restrict range to modern Dababba
1071 Wazir(board, flags, rf, ff, callback, closure);
1073 Rook(board, flags, rf, ff, callback, closure);
1076 /* Shogi Dragon King has to continue as Ferz after Rook moves */
1077 case SHOGI WhiteDragon:
1078 case SHOGI BlackDragon:
1079 case SHOGI WhitePDragon:
1080 case SHOGI BlackPDragon:
1082 Rook(board, flags, rf, ff, callback, closure);
1083 Ferz(board, flags, rf, ff, callback, closure);
1087 /* Capablanca Chancellor sets flag to continue as Knight */
1090 Rook(board, flags, rf, ff, callback, closure);
1091 if(gameInfo.variant == VariantSpartan) // in Spartan Chess Chancellor is used for Dragon King.
1092 Ferz(board, flags, rf, ff, callback, closure);
1094 Knight(board, flags, rf, ff, callback, closure);
1097 /* Shogi Rooks are ordinary Rooks */
1098 case SHOGI WhiteRook:
1099 case SHOGI BlackRook:
1100 case SHOGI WhitePRook:
1101 case SHOGI BlackPRook:
1104 Rook(board, flags, rf, ff, callback, closure);
1109 case SHOGI WhiteMother:
1110 case SHOGI BlackMother:
1112 Rook(board, flags, rf, ff, callback, closure);
1113 Bishop(board, flags, rf, ff, callback, closure);
1116 case SHOGI WhitePawn:
1117 StepForward(board, flags, rf, ff, callback, closure);
1120 case SHOGI BlackPawn:
1121 StepBackward(board, flags, rf, ff, callback, closure);
1125 if(gameInfo.variant != VariantMakruk && gameInfo.variant != VariantASEAN) goto commoner;
1126 case SHOGI WhiteFerz:
1127 Ferz(board, flags, rf, ff, callback, closure);
1128 StepForward(board, flags, rf, ff, callback, closure);
1132 if(gameInfo.variant != VariantMakruk && gameInfo.variant != VariantASEAN) goto commoner;
1133 case SHOGI BlackFerz:
1134 StepBackward(board, flags, rf, ff, callback, closure);
1138 /* [HGM] support Shatranj pieces */
1139 Ferz(board, flags, rf, ff, callback, closure);
1144 Knight(board, flags, rf, ff, callback, closure); // [HGM] superchess: use for Centaur
1147 case SHOGI WhiteMonarch:
1148 case SHOGI BlackMonarch:
1149 case SHOGI WhiteKing:
1150 case SHOGI BlackKing:
1153 Ferz(board, flags, rf, ff, callback, closure);
1154 Wazir(board, flags, rf, ff, callback, closure);
1157 case WhiteNightrider:
1158 case BlackNightrider:
1159 for (i = -1; i <= 1; i += 2)
1160 for (j = -1; j <= 1; j += 2)
1161 for (s = 1; s <= 2; s++) { int k;
1164 ft = ff + k*j*(3-s);
1165 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
1166 if (SameColor(board[rf][ff], board[rt][ft])) break;
1167 callback(board, flags, NormalMove,
1168 rf, ff, rt, ft, closure);
1169 if (board[rt][ft] != EmptySquare) break;
1175 Bishop(board, flags, rf, ff, callback, closure);
1176 Rook(board, flags, rf, ff, callback, closure);
1177 Knight(board, flags, rf, ff, callback, closure);
1180 // Use Lance as Berolina / Spartan Pawn.
1182 if(gameInfo.variant == VariantSuper) goto Amazon;
1183 if (rf < BOARD_HEIGHT-1 && BlackPiece(board[rf + 1][ff]))
1184 callback(board, flags,
1185 rf >= BOARD_HEIGHT-1-promoRank ? WhitePromotion : NormalMove,
1186 rf, ff, rf + 1, ff, closure);
1187 for (s = -1; s <= 1; s += 2) {
1188 if (rf < BOARD_HEIGHT-1 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT && board[rf + 1][ff + s] == EmptySquare)
1189 callback(board, flags,
1190 rf >= BOARD_HEIGHT-1-promoRank ? WhitePromotion : NormalMove,
1191 rf, ff, rf + 1, ff + s, closure);
1192 if (rf == 1 && ff + 2*s >= BOARD_LEFT && ff + 2*s < BOARD_RGHT && board[3][ff + 2*s] == EmptySquare )
1193 callback(board, flags, NormalMove, rf, ff, 3, ff + 2*s, closure);
1198 if(gameInfo.variant == VariantSuper) goto Amazon;
1199 if (rf > 0 && WhitePiece(board[rf - 1][ff]))
1200 callback(board, flags,
1201 rf <= promoRank ? BlackPromotion : NormalMove,
1202 rf, ff, rf - 1, ff, closure);
1203 for (s = -1; s <= 1; s += 2) {
1204 if (rf > 0 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT && board[rf - 1][ff + s] == EmptySquare)
1205 callback(board, flags,
1206 rf <= promoRank ? BlackPromotion : NormalMove,
1207 rf, ff, rf - 1, ff + s, closure);
1208 if (rf == BOARD_HEIGHT-2 && ff + 2*s >= BOARD_LEFT && ff + 2*s < BOARD_RGHT && board[rf-2][ff + 2*s] == EmptySquare )
1209 callback(board, flags, NormalMove, rf, ff, rf-2, ff + 2*s, closure);
1213 case SHOGI WhiteNothing:
1214 case SHOGI BlackNothing:
1215 case SHOGI WhiteLion:
1216 case SHOGI BlackLion:
1219 for(rt = rf - 2; rt <= rf + 2; rt++) for(ft = ff - 2; ft <= ff + 2; ft++) {
1220 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) continue;
1221 if (!(ff == ft && rf == rt) && SameColor(board[rf][ff], board[rt][ft])) continue;
1222 i = (killX >= 0 && (rt-killY)*(rt-killY) + (killX-ft)*(killX-ft) < 3); legNr += 2*i;
1223 callback(board, flags, (rt-rf)*(rt-rf) + (ff-ft)*(ff-ft) < 3 && board[rt][ft] != EmptySquare ? FirstLeg : NormalMove,
1224 rf, ff, rt, ft, closure);
1229 case SHOGI WhiteFalcon:
1230 case SHOGI BlackFalcon:
1231 case SHOGI WhitePDagger:
1232 case SHOGI BlackPDagger:
1233 SlideSideways(board, flags, rf, ff, callback, closure);
1234 StepVertical(board, flags, rf, ff, callback, closure);
1237 case SHOGI WhiteCobra:
1238 case SHOGI BlackCobra:
1239 StepVertical(board, flags, rf, ff, callback, closure);
1242 case SHOGI (PROMO WhiteFerz):
1243 if(gameInfo.variant == VariantShogi) goto WhiteGold;
1244 case SHOGI (PROMO BlackFerz):
1245 if(gameInfo.variant == VariantShogi) goto BlackGold;
1246 case SHOGI WhitePSword:
1247 case SHOGI BlackPSword:
1248 SlideVertical(board, flags, rf, ff, callback, closure);
1249 StepSideways(board, flags, rf, ff, callback, closure);
1252 case SHOGI WhiteUnicorn:
1253 case SHOGI BlackUnicorn:
1254 Ferz(board, flags, rf, ff, callback, closure);
1255 StepVertical(board, flags, rf, ff, callback, closure);
1258 case SHOGI WhiteMan:
1259 StepDiagForward(board, flags, rf, ff, callback, closure);
1260 StepVertical(board, flags, rf, ff, callback, closure);
1263 case SHOGI BlackMan:
1264 StepDiagBackward(board, flags, rf, ff, callback, closure);
1265 StepVertical(board, flags, rf, ff, callback, closure);
1268 case SHOGI WhiteHCrown:
1269 case SHOGI BlackHCrown:
1270 Bishop(board, flags, rf, ff, callback, closure);
1271 SlideSideways(board, flags, rf, ff, callback, closure);
1274 case SHOGI WhiteCrown:
1275 case SHOGI BlackCrown:
1276 Bishop(board, flags, rf, ff, callback, closure);
1277 SlideVertical(board, flags, rf, ff, callback, closure);
1280 case SHOGI WhiteHorned:
1281 Sting(board, flags, rf, ff, 1, 0, callback, closure);
1282 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1283 if(killX >= 0) break;
1284 Bishop(board, flags, rf, ff, callback, closure);
1285 SlideSideways(board, flags, rf, ff, callback, closure);
1286 SlideBackward(board, flags, rf, ff, callback, closure);
1289 case SHOGI BlackHorned:
1290 Sting(board, flags, rf, ff, -1, 0, callback, closure);
1291 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1292 if(killX >= 0) break;
1293 Bishop(board, flags, rf, ff, callback, closure);
1294 SlideSideways(board, flags, rf, ff, callback, closure);
1295 SlideForward(board, flags, rf, ff, callback, closure);
1298 case SHOGI WhiteEagle:
1299 Sting(board, flags, rf, ff, 1, 1, callback, closure);
1300 Sting(board, flags, rf, ff, 1, -1, callback, closure);
1301 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1302 if(killX >= 0) break;
1303 Rook(board, flags, rf, ff, callback, closure);
1304 SlideDiagBackward(board, flags, rf, ff, callback, closure);
1307 case SHOGI BlackEagle:
1308 Sting(board, flags, rf, ff, -1, 1, callback, closure);
1309 Sting(board, flags, rf, ff, -1, -1, callback, closure);
1310 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1311 if(killX >= 0) break;
1312 Rook(board, flags, rf, ff, callback, closure);
1313 SlideDiagForward(board, flags, rf, ff, callback, closure);
1316 case SHOGI WhiteDolphin:
1317 case SHOGI BlackHorse:
1318 SlideDiagBackward(board, flags, rf, ff, callback, closure);
1319 SlideVertical(board, flags, rf, ff, callback, closure);
1322 case SHOGI BlackDolphin:
1323 case SHOGI WhiteHorse:
1324 SlideDiagForward(board, flags, rf, ff, callback, closure);
1325 SlideVertical(board, flags, rf, ff, callback, closure);
1328 case SHOGI WhiteLance:
1329 SlideForward(board, flags, rf, ff, callback, closure);
1332 case SHOGI BlackLance:
1333 SlideBackward(board, flags, rf, ff, callback, closure);
1336 case WhiteFalcon: // [HGM] wild: for wildcards, self-capture symbolizes move to anywhere
1340 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1353 int rFilter, fFilter; // [HGM] speed: sorry, but I get a bit tired of this closure madness
1354 Board xqCheckers, nullBoard;
1356 extern void GenLegalCallback P((Board board, int flags, ChessMove kind,
1357 int rf, int ff, int rt, int ft,
1361 GenLegalCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1363 register GenLegalClosure *cl = (GenLegalClosure *) closure;
1365 if(rFilter >= 0 && rFilter != rt || fFilter >= 0 && fFilter != ft) return; // [HGM] speed: ignore moves with wrong to-square
1367 if (board[EP_STATUS] == EP_IRON_LION && (board[rt][ft] == WhiteLion || board[rt][ft] == BlackLion)) return; //[HGM] lion
1369 if (!(flags & F_IGNORE_CHECK) ) {
1370 int check, promo = (gameInfo.variant == VariantSpartan && kind == BlackPromotion);
1373 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++)
1374 kings += (board[r][f] == BlackKing);
1378 board[rf][ff] = BlackKing; // [HGM] spartan: promote to King before check-test
1380 check = CheckTest(board, flags, rf, ff, rt, ft,
1381 kind == WhiteCapturesEnPassant ||
1382 kind == BlackCapturesEnPassant);
1383 if(promo) board[rf][ff] = BlackLance;
1386 if (flags & F_ATOMIC_CAPTURE) {
1387 if (board[rt][ft] != EmptySquare ||
1388 kind == WhiteCapturesEnPassant || kind == BlackCapturesEnPassant) {
1390 ChessSquare king = (flags & F_WHITE_ON_MOVE) ? WhiteKing : BlackKing;
1391 if (board[rf][ff] == king) return;
1392 for (r = rt-1; r <= rt+1; r++) {
1393 for (f = ft-1; f <= ft+1; f++) {
1394 if (r >= 0 && r < BOARD_HEIGHT && f >= BOARD_LEFT && f < BOARD_RGHT &&
1395 board[r][f] == king) return;
1400 cl->cb(board, flags, kind, rf, ff, rt, ft, cl->cl);
1407 int captures; // [HGM] losers
1408 } LegalityTestClosure;
1411 /* Like GenPseudoLegal, but (1) include castling moves, (2) unless
1412 F_IGNORE_CHECK is set in the flags, omit moves that would leave the
1413 king in check, and (3) if F_ATOMIC_CAPTURE is set in the flags, omit
1414 moves that would destroy your own king. The CASTLE_OK flags are
1415 true if castling is not yet ruled out by a move of the king or
1416 rook. Return TRUE if the player on move is currently in check and
1417 F_IGNORE_CHECK is not set. [HGM] add castlingRights parameter */
1419 GenLegal (Board board, int flags, MoveCallback callback, VOIDSTAR closure, ChessSquare filter)
1422 int ff, ft, k, left, right, swap;
1423 int ignoreCheck = (flags & F_IGNORE_CHECK) != 0;
1424 ChessSquare wKing = WhiteKing, bKing = BlackKing, *castlingRights = board[CASTLING];
1425 int inCheck = !ignoreCheck && CheckTest(board, flags, -1, -1, -1, -1, FALSE); // kludge alert: this would mark pre-existing checkers if status==1
1430 xqCheckers[EP_STATUS] *= 2; // quasi: if previous CheckTest has been marking, we now set flag for suspending same checkers
1431 if(filter == EmptySquare) rFilter = fFilter = -1; // [HGM] speed: do not filter on square if we do not filter on piece
1432 GenPseudoLegal(board, flags, GenLegalCallback, (VOIDSTAR) &cl, filter);
1434 if (inCheck) return TRUE;
1436 /* Generate castling moves */
1437 if(gameInfo.variant == VariantKnightmate) { /* [HGM] Knightmate */
1438 wKing = WhiteUnicorn; bKing = BlackUnicorn;
1441 p = (flags & F_WHITE_ON_MOVE ? pieceDesc[wKing] : pieceDesc[bKing]);
1442 if(p && strchr(p, 'O')) return FALSE; // [HGM] gen: castlings were already generated from string
1444 for (ff = BOARD_WIDTH>>1; ff >= (BOARD_WIDTH-1)>>1; ff-- /*ics wild 1*/) {
1445 if ((flags & F_WHITE_ON_MOVE) &&
1446 (flags & F_WHITE_KCASTLE_OK) &&
1447 board[0][ff] == wKing &&
1448 board[0][ff + 1] == EmptySquare &&
1449 board[0][ff + 2] == EmptySquare &&
1450 board[0][BOARD_RGHT-3] == EmptySquare &&
1451 board[0][BOARD_RGHT-2] == EmptySquare &&
1452 board[0][BOARD_RGHT-1] == WhiteRook &&
1453 castlingRights[0] != NoRights && /* [HGM] check rights */
1454 ( castlingRights[2] == ff || castlingRights[6] == ff ) &&
1456 (!CheckTest(board, flags, 0, ff, 0, ff + 1, FALSE) &&
1457 !CheckTest(board, flags, 0, ff, 0, BOARD_RGHT-3, FALSE) &&
1458 (gameInfo.variant != VariantJanus || !CheckTest(board, flags, 0, ff, 0, BOARD_RGHT-2, FALSE)) &&
1459 !CheckTest(board, flags, 0, ff, 0, ff + 2, FALSE)))) {
1461 callback(board, flags,
1462 ff==BOARD_WIDTH>>1 ? WhiteKingSideCastle : WhiteKingSideCastleWild,
1463 0, ff, 0, ff + ((gameInfo.boardWidth+2)>>2) + (gameInfo.variant == VariantJanus), closure);
1465 if ((flags & F_WHITE_ON_MOVE) &&
1466 (flags & F_WHITE_QCASTLE_OK) &&
1467 board[0][ff] == wKing &&
1468 board[0][ff - 1] == EmptySquare &&
1469 board[0][ff - 2] == EmptySquare &&
1470 board[0][BOARD_LEFT+2] == EmptySquare &&
1471 board[0][BOARD_LEFT+1] == EmptySquare &&
1472 board[0][BOARD_LEFT+0] == WhiteRook &&
1473 castlingRights[1] != NoRights && /* [HGM] check rights */
1474 ( castlingRights[2] == ff || castlingRights[6] == ff ) &&
1476 (!CheckTest(board, flags, 0, ff, 0, ff - 1, FALSE) &&
1477 !CheckTest(board, flags, 0, ff, 0, BOARD_LEFT+3, FALSE) &&
1478 !CheckTest(board, flags, 0, ff, 0, ff - 2, FALSE)))) {
1480 callback(board, flags,
1481 ff==BOARD_WIDTH>>1 ? WhiteQueenSideCastle : WhiteQueenSideCastleWild,
1482 0, ff, 0, ff - ((gameInfo.boardWidth+2)>>2), closure);
1484 if (!(flags & F_WHITE_ON_MOVE) &&
1485 (flags & F_BLACK_KCASTLE_OK) &&
1486 board[BOARD_HEIGHT-1][ff] == bKing &&
1487 board[BOARD_HEIGHT-1][ff + 1] == EmptySquare &&
1488 board[BOARD_HEIGHT-1][ff + 2] == EmptySquare &&
1489 board[BOARD_HEIGHT-1][BOARD_RGHT-3] == EmptySquare &&
1490 board[BOARD_HEIGHT-1][BOARD_RGHT-2] == EmptySquare &&
1491 board[BOARD_HEIGHT-1][BOARD_RGHT-1] == BlackRook &&
1492 castlingRights[3] != NoRights && /* [HGM] check rights */
1493 ( castlingRights[5] == ff || castlingRights[7] == ff ) &&
1495 (!CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff + 1, FALSE) &&
1496 !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, BOARD_RGHT-3, FALSE) &&
1497 (gameInfo.variant != VariantJanus || !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, BOARD_RGHT-2, FALSE)) &&
1498 !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff + 2, FALSE)))) {
1500 callback(board, flags,
1501 ff==BOARD_WIDTH>>1 ? BlackKingSideCastle : BlackKingSideCastleWild,
1502 BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff + ((gameInfo.boardWidth+2)>>2) + (gameInfo.variant == VariantJanus), closure);
1504 if (!(flags & F_WHITE_ON_MOVE) &&
1505 (flags & F_BLACK_QCASTLE_OK) &&
1506 board[BOARD_HEIGHT-1][ff] == bKing &&
1507 board[BOARD_HEIGHT-1][ff - 1] == EmptySquare &&
1508 board[BOARD_HEIGHT-1][ff - 2] == EmptySquare &&
1509 board[BOARD_HEIGHT-1][BOARD_LEFT+2] == EmptySquare &&
1510 board[BOARD_HEIGHT-1][BOARD_LEFT+1] == EmptySquare &&
1511 board[BOARD_HEIGHT-1][BOARD_LEFT+0] == BlackRook &&
1512 castlingRights[4] != NoRights && /* [HGM] check rights */
1513 ( castlingRights[5] == ff || castlingRights[7] == ff ) &&
1515 (!CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff - 1, FALSE) &&
1516 !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, BOARD_LEFT+3, FALSE) &&
1517 !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff - 2, FALSE)))) {
1519 callback(board, flags,
1520 ff==BOARD_WIDTH>>1 ? BlackQueenSideCastle : BlackQueenSideCastleWild,
1521 BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff - ((gameInfo.boardWidth+2)>>2), closure);
1525 if((swap = gameInfo.variant == VariantSChess) || flags & F_FRC_TYPE_CASTLING) {
1527 /* generate all potential FRC castling moves (KxR), ignoring flags */
1528 /* [HGM] test if the Rooks we find have castling rights */
1529 /* In S-Chess we generate RxK for allowed castlings, for gating at Rook square */
1532 if ((flags & F_WHITE_ON_MOVE) != 0) {
1533 ff = castlingRights[2]; /* King file if we have any rights */
1534 if(ff != NoRights && board[0][ff] == WhiteKing) {
1535 if (appData.debugMode) {
1536 fprintf(debugFP, "FRC castling, %d %d %d %d %d %d\n",
1537 castlingRights[0],castlingRights[1],ff,castlingRights[3],castlingRights[4],castlingRights[5]);
1539 ft = castlingRights[0]; /* Rook file if we have H-side rights */
1541 right = BOARD_RGHT-2;
1542 if(ff == BOARD_RGHT-2) left = right = ff-1; /* special case */
1543 for(k=left; k<=right && ft != NoRights; k++) /* first test if blocked */
1544 if(k != ft && board[0][k] != EmptySquare) ft = NoRights;
1545 for(k=left; k<right && ft != NoRights; k++) /* then if not checked */
1546 if(!ignoreCheck && CheckTest(board, flags, 0, ff, 0, k, FALSE)) ft = NoRights;
1547 if(ft != NoRights && board[0][ft] == WhiteRook) {
1548 if(flags & F_FRC_TYPE_CASTLING) callback(board, flags, WhiteHSideCastleFR, 0, ff, 0, ft, closure);
1549 if(swap) callback(board, flags, WhiteHSideCastleFR, 0, ft, 0, ff, closure);
1552 ft = castlingRights[1]; /* Rook file if we have A-side rights */
1553 left = BOARD_LEFT+2;
1555 if(ff <= BOARD_LEFT+2) { left = ff+1; right = BOARD_LEFT+3; }
1556 for(k=left; k<=right && ft != NoRights; k++) /* first test if blocked */
1557 if(k != ft && board[0][k] != EmptySquare) ft = NoRights;
1558 if(ft == 0 && ff != 1 && board[0][1] != EmptySquare) ft = NoRights; /* Rook can be blocked on b1 */
1559 if(ff > BOARD_LEFT+2)
1560 for(k=left+1; k<=right && ft != NoRights; k++) /* then if not checked */
1561 if(!ignoreCheck && CheckTest(board, flags, 0, ff, 0, k, FALSE)) ft = NoRights;
1562 if(ft != NoRights && board[0][ft] == WhiteRook) {
1563 if(flags & F_FRC_TYPE_CASTLING) callback(board, flags, WhiteASideCastleFR, 0, ff, 0, ft, closure);
1564 if(swap) callback(board, flags, WhiteASideCastleFR, 0, ft, 0, ff, closure);
1568 ff = castlingRights[5]; /* King file if we have any rights */
1569 if(ff != NoRights && board[BOARD_HEIGHT-1][ff] == BlackKing) {
1570 ft = castlingRights[3]; /* Rook file if we have H-side rights */
1572 right = BOARD_RGHT-2;
1573 if(ff == BOARD_RGHT-2) left = right = ff-1; /* special case */
1574 for(k=left; k<=right && ft != NoRights; k++) /* first test if blocked */
1575 if(k != ft && board[BOARD_HEIGHT-1][k] != EmptySquare) ft = NoRights;
1576 for(k=left; k<right && ft != NoRights; k++) /* then if not checked */
1577 if(!ignoreCheck && CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, k, FALSE)) ft = NoRights;
1578 if(ft != NoRights && board[BOARD_HEIGHT-1][ft] == BlackRook) {
1579 if(flags & F_FRC_TYPE_CASTLING) callback(board, flags, BlackHSideCastleFR, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ft, closure);
1580 if(swap) callback(board, flags, BlackHSideCastleFR, BOARD_HEIGHT-1, ft, BOARD_HEIGHT-1, ff, closure);
1583 ft = castlingRights[4]; /* Rook file if we have A-side rights */
1584 left = BOARD_LEFT+2;
1586 if(ff <= BOARD_LEFT+2) { left = ff+1; right = BOARD_LEFT+3; }
1587 for(k=left; k<=right && ft != NoRights; k++) /* first test if blocked */
1588 if(k != ft && board[BOARD_HEIGHT-1][k] != EmptySquare) ft = NoRights;
1589 if(ft == 0 && ff != 1 && board[BOARD_HEIGHT-1][1] != EmptySquare) ft = NoRights; /* Rook can be blocked on b8 */
1590 if(ff > BOARD_LEFT+2)
1591 for(k=left+1; k<=right && ft != NoRights; k++) /* then if not checked */
1592 if(!ignoreCheck && CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, k, FALSE)) ft = NoRights;
1593 if(ft != NoRights && board[BOARD_HEIGHT-1][ft] == BlackRook) {
1594 if(flags & F_FRC_TYPE_CASTLING) callback(board, flags, BlackASideCastleFR, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ft, closure);
1595 if(swap) callback(board, flags, BlackASideCastleFR, BOARD_HEIGHT-1, ft, BOARD_HEIGHT-1, ff, closure);
1612 extern void CheckTestCallback P((Board board, int flags, ChessMove kind,
1613 int rf, int ff, int rt, int ft,
1618 CheckTestCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1620 register CheckTestClosure *cl = (CheckTestClosure *) closure;
1622 if (rt == cl->rking && ft == cl->fking) {
1623 if(xqCheckers[EP_STATUS] >= 2 && xqCheckers[rf][ff]) return; // checker is piece with suspended checking power
1625 xqCheckers[rf][ff] = xqCheckers[EP_STATUS] & 1; // remember who is checking (if status == 1)
1627 if( board[EP_STATUS] == EP_ROYAL_LION && (board[rt][ft] == WhiteLion || board[rt][ft] == BlackLion)
1628 && (gameInfo.variant != VariantLion || board[rf][ff] != WhiteKing && board[rf][ff] != BlackKing) )
1629 cl->check++; // [HGM] lion: forbidden counterstrike against Lion equated to putting yourself in check
1633 /* If the player on move were to move from (rf, ff) to (rt, ft), would
1634 he leave himself in check? Or if rf == -1, is the player on move
1635 in check now? enPassant must be TRUE if the indicated move is an
1636 e.p. capture. The possibility of castling out of a check along the
1637 back rank is not accounted for (i.e., we still return nonzero), as
1638 this is illegal anyway. Return value is the number of times the
1639 king is in check. */
1641 CheckTest (Board board, int flags, int rf, int ff, int rt, int ft, int enPassant)
1643 CheckTestClosure cl;
1644 ChessSquare king = flags & F_WHITE_ON_MOVE ? WhiteKing : BlackKing;
1645 ChessSquare captured = EmptySquare, ep=0, trampled=0;
1646 int saveKill = killX;
1647 /* Suppress warnings on uninitialized variables */
1649 if(gameInfo.variant == VariantXiangqi)
1650 king = flags & F_WHITE_ON_MOVE ? WhiteWazir : BlackWazir;
1651 if(gameInfo.variant == VariantKnightmate)
1652 king = flags & F_WHITE_ON_MOVE ? WhiteUnicorn : BlackUnicorn;
1653 if(gameInfo.variant == VariantChu || gameInfo.variant == VariantShogi) { // strictly speaking this is not needed, as Chu officially has no check
1654 int r, f, k = king, royals=0, prince = flags & F_WHITE_ON_MOVE ? WhiteMonarch : BlackMonarch;
1655 if(gameInfo.variant == VariantShogi) prince -= 11; // White/BlackFalcon
1656 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++) {
1657 if(board[r][f] == k || board[r][f] == prince) {
1658 if(++royals > 1) return FALSE; // no check if we have two royals (ignores double captureby Lion!)
1659 king = board[r][f]; // remember hich one we had
1666 captured = board[rf][ft];
1667 board[rf][ft] = EmptySquare;
1669 captured = board[rt][ft];
1670 if(killX >= 0) { trampled = board[killY][killX]; board[killY][killX] = EmptySquare; killX = -1; }
1672 if(rf == DROP_RANK) board[rt][ft] = ff; else { // [HGM] drop
1673 board[rt][ft] = board[rf][ff];
1674 if(rf != rt || ff != ft) board[rf][ff] = EmptySquare;
1676 ep = board[EP_STATUS];
1677 if( captured == WhiteLion || captured == BlackLion ) { // [HGM] lion: Chu Lion-capture rules
1678 ChessSquare victim = saveKill < 0 ? EmptySquare : trampled;
1679 if( (board[rt][ft] == WhiteLion || board[rt][ft] == BlackLion) && // capturer is Lion
1680 (ff - ft > 1 || ft - ff > 1 || rf - rt > 1 || rt - rf > 1) && // captures from a distance
1681 (victim == EmptySquare || victim == WhitePawn || victim == BlackPawn // no or worthless 'bridge'
1682 || victim == WhiteCobra || victim == BlackCobra) ) // (Pawn or Go Between)
1683 board[EP_STATUS] = EP_ROYAL_LION; // on distant Lion x Lion victim must not be pseudo-legally protected
1687 /* For compatibility with ICS wild 9, we scan the board in the
1688 order a1, a2, a3, ... b1, b2, ..., h8 to find the first king,
1689 and we test only whether that one is in check. */
1690 for (cl.fking = BOARD_LEFT+0; cl.fking < BOARD_RGHT; cl.fking++)
1691 for (cl.rking = 0; cl.rking < BOARD_HEIGHT; cl.rking++) {
1692 if (board[cl.rking][cl.fking] == king) {
1694 if(gameInfo.variant == VariantXiangqi) {
1695 /* [HGM] In Xiangqi opposing Kings means check as well */
1697 dir = (king >= BlackPawn) ? -1 : 1;
1698 for( i=cl.rking+dir; i>=0 && i<BOARD_HEIGHT &&
1699 board[i][cl.fking] == EmptySquare; i+=dir );
1700 if(i>=0 && i<BOARD_HEIGHT &&
1701 board[i][cl.fking] == (dir>0 ? BlackWazir : WhiteWazir) )
1704 GenPseudoLegal(board, flags ^ F_WHITE_ON_MOVE, CheckTestCallback, (VOIDSTAR) &cl, EmptySquare);
1705 if(gameInfo.variant != VariantSpartan || cl.check == 0) // in Spartan Chess go on to test if other King is checked too
1706 goto undo_move; /* 2-level break */
1713 if(rf != DROP_RANK) // [HGM] drop
1714 board[rf][ff] = board[rt][ft];
1716 board[rf][ft] = captured;
1717 board[rt][ft] = EmptySquare;
1719 if(saveKill >= 0) board[killY][killX = saveKill] = trampled;
1720 board[rt][ft] = captured;
1722 board[EP_STATUS] = ep;
1725 return cl.fking < BOARD_RGHT ? cl.check : 1000; // [HGM] atomic: return 1000 if we have no king
1729 HasLion (Board board, int flags)
1731 int lion = F_WHITE_ON_MOVE & flags ? WhiteLion : BlackLion;
1733 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++)
1734 if(board[r][f] == lion) return 1;
1739 LegalDrop (Board board, int flags, ChessSquare piece, int rt, int ft)
1740 { // [HGM] put drop legality testing in separate routine for clarity
1742 if(appData.debugMode) fprintf(debugFP, "LegalDrop: %d @ %d,%d)\n", piece, ft, rt);
1743 if(board[rt][ft] != EmptySquare) return ImpossibleMove; // must drop to empty square
1744 n = PieceToNumber(piece);
1745 if((gameInfo.holdingsWidth == 0 || (flags & F_WHITE_ON_MOVE ? board[n][BOARD_WIDTH-1] : board[BOARD_HEIGHT-1-n][0]) != piece)
1746 && gameInfo.variant != VariantBughouse) // in bughouse we don't check for availability, because ICS doesn't always tell us
1747 return ImpossibleMove; // piece not available
1748 if(gameInfo.variant == VariantShogi) { // in Shogi lots of drops are forbidden!
1749 if((piece == WhitePawn || piece == WhiteQueen) && rt == BOARD_HEIGHT-1 ||
1750 (piece == BlackPawn || piece == BlackQueen) && rt == 0 ||
1751 piece == WhiteKnight && rt > BOARD_HEIGHT-3 ||
1752 piece == BlackKnight && rt < 2 ) return IllegalMove; // e.g. where dropped piece has no moves
1753 if(piece == WhitePawn || piece == BlackPawn) {
1754 int r, max = 1 + (BOARD_HEIGHT == 7); // two Pawns per file in Tori!
1755 for(r=1; r<BOARD_HEIGHT-1; r++)
1756 if(!(max -= (board[r][ft] == piece))) return IllegalMove; // or there already is a Pawn in file
1757 // should still test if we mate with this Pawn
1759 } else if(gameInfo.variant == VariantSChess) { // only back-rank drops
1760 if (rt != (piece < BlackPawn ? 0 : BOARD_HEIGHT-1)) return IllegalMove;
1762 if( (piece == WhitePawn || piece == BlackPawn) &&
1763 (rt == 0 || rt == BOARD_HEIGHT -1 ) )
1764 return IllegalMove; /* no pawn drops on 1st/8th */
1766 if(appData.debugMode) fprintf(debugFP, "LegalDrop: %d @ %d,%d)\n", piece, ft, rt);
1767 if (!(flags & F_IGNORE_CHECK) &&
1768 CheckTest(board, flags, DROP_RANK, piece, rt, ft, FALSE) ) return IllegalMove;
1769 return flags & F_WHITE_ON_MOVE ? WhiteDrop : BlackDrop;
1772 extern void LegalityTestCallback P((Board board, int flags, ChessMove kind,
1773 int rf, int ff, int rt, int ft,
1777 LegalityTestCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1779 register LegalityTestClosure *cl = (LegalityTestClosure *) closure;
1781 if(board[rt][ft] != EmptySquare || kind==WhiteCapturesEnPassant || kind==BlackCapturesEnPassant)
1782 cl->captures++; // [HGM] losers: count legal captures
1783 if (rf == cl->rf && ff == cl->ff && rt == cl->rt && ft == cl->ft)
1788 LegalityTest (Board board, int flags, int rf, int ff, int rt, int ft, int promoChar)
1790 LegalityTestClosure cl; ChessSquare piece, filterPiece;
1792 if(quickFlag) flags = flags & ~1 | quickFlag & 1; // [HGM] speed: in quick mode quickFlag specifies side-to-move.
1793 if(rf == DROP_RANK) return LegalDrop(board, flags, ff, rt, ft);
1794 piece = filterPiece = board[rf][ff];
1795 if(PieceToChar(piece) == '~') filterPiece = DEMOTED(piece);
1797 /* [HGM] Cobra and Falcon are wildcard pieces; consider all their moves legal */
1798 /* (perhaps we should disallow moves that obviously leave us in check?) */
1799 if((piece == WhiteFalcon || piece == BlackFalcon ||
1800 piece == WhiteCobra || piece == BlackCobra) && gameInfo.variant != VariantChu && !pieceDesc[piece])
1801 return CheckTest(board, flags, rf, ff, rt, ft, FALSE) ? IllegalMove : NormalMove;
1805 cl.rt = rFilter = rt; // [HGM] speed: filter on to-square
1806 cl.ft = fFilter = ft;
1807 cl.kind = IllegalMove;
1808 cl.captures = 0; // [HGM] losers: prepare to count legal captures.
1809 if(flags & F_MANDATORY_CAPTURE) filterPiece = EmptySquare; // [HGM] speed: do not filter in suicide, to find all captures
1810 GenLegal(board, flags, LegalityTestCallback, (VOIDSTAR) &cl, filterPiece);
1811 if((flags & F_MANDATORY_CAPTURE) && cl.captures && board[rt][ft] == EmptySquare
1812 && cl.kind != WhiteCapturesEnPassant && cl.kind != BlackCapturesEnPassant)
1813 return(IllegalMove); // [HGM] losers: if there are legal captures, non-capts are illegal
1815 if(promoChar == 'x') promoChar = NULLCHAR; // [HGM] is this ever the case?
1816 if(gameInfo.variant == VariantSChess && promoChar && promoChar != '=' && board[rf][ff] != WhitePawn && board[rf][ff] != BlackPawn) {
1817 if(board[rf][ff] < BlackPawn) { // white
1818 if(rf != 0) return IllegalMove; // must be on back rank
1819 if(!(board[VIRGIN][ff] & VIRGIN_W)) return IllegalMove; // non-virgin
1820 if(board[PieceToNumber(CharToPiece(ToUpper(promoChar)))][BOARD_WIDTH-2] == 0) return ImpossibleMove;// must be in stock
1821 if(cl.kind == WhiteHSideCastleFR && (ff == BOARD_RGHT-2 || ff == BOARD_RGHT-3)) return ImpossibleMove;
1822 if(cl.kind == WhiteASideCastleFR && (ff == BOARD_LEFT+2 || ff == BOARD_LEFT+3)) return ImpossibleMove;
1824 if(rf != BOARD_HEIGHT-1) return IllegalMove;
1825 if(!(board[VIRGIN][ff] & VIRGIN_B)) return IllegalMove; // non-virgin
1826 if(board[BOARD_HEIGHT-1-PieceToNumber(CharToPiece(ToLower(promoChar)))][1] == 0) return ImpossibleMove;
1827 if(cl.kind == BlackHSideCastleFR && (ff == BOARD_RGHT-2 || ff == BOARD_RGHT-3)) return ImpossibleMove;
1828 if(cl.kind == BlackASideCastleFR && (ff == BOARD_LEFT+2 || ff == BOARD_LEFT+3)) return ImpossibleMove;
1831 if(gameInfo.variant == VariantChu) {
1832 if(cl.kind != NormalMove || promoChar == NULLCHAR || promoChar == '=') return cl.kind;
1833 if(promoChar != '+')
1834 return CharToPiece(promoChar) == EmptySquare ? ImpossibleMove : IllegalMove;
1835 if(PieceToChar(CHUPROMOTED(board[rf][ff])) != '+') {
1836 if(PieceToChar(CHUPROMOTED (board[rf][ff] < BlackPawn ? WhitePawn : BlackPawn)) != '.')
1837 return ImpossibleMove;
1839 return flags & F_WHITE_ON_MOVE ? WhitePromotion : BlackPromotion;
1841 if(gameInfo.variant == VariantShogi) {
1842 /* [HGM] Shogi promotions. '=' means defer */
1843 if(rf != DROP_RANK && cl.kind == NormalMove) {
1844 ChessSquare piece = board[rf][ff];
1845 int zone = BOARD_HEIGHT/3 + (BOARD_HEIGHT == 8);
1847 if(promoChar == PieceToChar(BlackQueen)) promoChar = NULLCHAR; /* [HGM] Kludge */
1848 if(promoChar == 'd' && (piece == WhiteRook || piece == BlackRook) ||
1849 promoChar == 'h' && (piece == WhiteBishop || piece == BlackBishop) ||
1850 promoChar == 'g' && (piece <= WhiteFerz || piece <= BlackFerz && piece >= BlackPawn) )
1851 promoChar = '+'; // allowed ICS notations
1852 if(appData.debugMode)fprintf(debugFP,"SHOGI promoChar = %c\n", promoChar ? promoChar : '-');
1853 if(promoChar != NULLCHAR && promoChar != '+' && promoChar != '=')
1854 return CharToPiece(promoChar) == EmptySquare ? ImpossibleMove : IllegalMove;
1855 else if(flags & F_WHITE_ON_MOVE) {
1856 if( (int) piece < (int) WhiteWazir &&
1857 (rf >= BOARD_HEIGHT - zone || rt >= BOARD_HEIGHT - zone) ) {
1858 if( (piece == WhitePawn || piece == WhiteQueen) && rt > BOARD_HEIGHT-2 ||
1859 piece == WhiteKnight && rt > BOARD_HEIGHT-3) /* promotion mandatory */
1860 cl.kind = promoChar == '=' ? IllegalMove : WhitePromotion;
1861 else /* promotion optional, default is defer */
1862 cl.kind = promoChar == '+' ? WhitePromotion : WhiteNonPromotion;
1863 } else cl.kind = promoChar == '+' ? IllegalMove : NormalMove;
1865 if( (int) piece < (int) BlackWazir && (rf < zone || rt < zone) ) {
1866 if( (piece == BlackPawn || piece == BlackQueen) && rt < 1 ||
1867 piece == BlackKnight && rt < 2 ) /* promotion obligatory */
1868 cl.kind = promoChar == '=' ? IllegalMove : BlackPromotion;
1869 else /* promotion optional, default is defer */
1870 cl.kind = promoChar == '+' ? BlackPromotion : BlackNonPromotion;
1871 } else cl.kind = promoChar == '+' ? IllegalMove : NormalMove;
1875 if (promoChar != NULLCHAR) {
1876 if(cl.kind == NormalMove && promoChar == '+') { // allow shogi-style promotion is pieceToChar specifies them
1877 ChessSquare piece = board[rf][ff];
1878 if(piece < BlackPawn ? piece > WhiteMan : piece > BlackMan) return ImpossibleMove; // already promoted
1879 // should test if in zone, really
1880 if(gameInfo.variant == VariantChuChess && (piece == WhiteKnight || piece == BlackKnight) && HasLion(board, flags))
1882 if(PieceToChar(PROMOTED(piece)) == '+') return flags & F_WHITE_ON_MOVE ? WhitePromotion : BlackPromotion;
1884 if(promoChar == '=') cl.kind = IllegalMove; else // [HGM] shogi: no deferred promotion outside Shogi
1885 if (cl.kind == WhitePromotion || cl.kind == BlackPromotion) {
1886 ChessSquare piece = CharToPiece(flags & F_WHITE_ON_MOVE ? ToUpper(promoChar) : ToLower(promoChar));
1887 if(piece == EmptySquare)
1888 cl.kind = ImpossibleMove; // non-existing piece
1889 if(gameInfo.variant == VariantChuChess && promoChar == 'l' && HasLion(board, flags)) {
1890 cl.kind = IllegalMove; // no two Lions
1891 } else if(gameInfo.variant == VariantSpartan && cl.kind == BlackPromotion ) {
1892 if(promoChar != PieceToChar(BlackKing)) {
1893 if(CheckTest(board, flags, rf, ff, rt, ft, FALSE)) cl.kind = IllegalMove; // [HGM] spartan: only promotion to King was possible
1894 if(piece == BlackLance) cl.kind = ImpossibleMove;
1895 } else { // promotion to King allowed only if we do not have two yet
1896 int r, f, kings = 0;
1897 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++) kings += (board[r][f] == BlackKing);
1898 if(kings == 2) cl.kind = IllegalMove;
1900 } else if(piece == WhitePawn && rt == BOARD_HEIGHT-1 ||
1901 piece == BlackPawn && rt == 0) cl.kind = IllegalMove; // cannot stay Pawn on last rank in any variant
1902 else if((piece == WhiteUnicorn || piece == BlackUnicorn) && gameInfo.variant == VariantKnightmate)
1903 cl.kind = IllegalMove; // promotion to Royal Knight not allowed
1904 else if((piece == WhiteKing || piece == BlackKing) && gameInfo.variant != VariantSuicide && gameInfo.variant != VariantGiveaway)
1905 cl.kind = IllegalMove; // promotion to King usually not allowed
1907 cl.kind = IllegalMove;
1917 extern void MateTestCallback P((Board board, int flags, ChessMove kind,
1918 int rf, int ff, int rt, int ft,
1922 MateTestCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1924 register MateTestClosure *cl = (MateTestClosure *) closure;
1929 /* Return MT_NONE, MT_CHECK, MT_CHECKMATE, or MT_STALEMATE */
1931 MateTest (Board board, int flags)
1934 int inCheck, r, f, myPieces=0, hisPieces=0, nrKing=0;
1935 ChessSquare king = flags & F_WHITE_ON_MOVE ? WhiteKing : BlackKing;
1937 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++) {
1938 // [HGM] losers: Count pieces and kings, to detect other unorthodox winning conditions
1939 nrKing += (board[r][f] == king); // stm has king
1940 if( board[r][f] != EmptySquare ) {
1941 if((int)board[r][f] <= (int)king && (int)board[r][f] >= (int)king - (int)WhiteKing + (int)WhitePawn)
1946 switch(gameInfo.variant) { // [HGM] losers: extinction wins
1947 case VariantShatranj:
1948 if(hisPieces == 1) return myPieces > 1 ? MT_BARE : MT_DRAW;
1952 if(nrKing == 0) return MT_NOKING;
1955 if(myPieces == 1) return MT_BARE;
1958 inCheck = GenLegal(board, flags, MateTestCallback, (VOIDSTAR) &cl, EmptySquare);
1959 // [HGM] 3check: yet to do!
1961 return inCheck ? MT_CHECK : MT_NONE;
1963 if(gameInfo.holdingsWidth && gameInfo.variant != VariantSuper && gameInfo.variant != VariantGreat
1964 && gameInfo.variant != VariantSChess && gameInfo.variant != VariantGrand) { // drop game
1965 int r, f, n, holdings = flags & F_WHITE_ON_MOVE ? BOARD_WIDTH-1 : 0;
1966 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++) if(board[r][f] == EmptySquare) // all empty squares
1967 for(n=0; n<BOARD_HEIGHT; n++) // all pieces in hand
1968 if(board[n][holdings] != EmptySquare) {
1969 int moveType = LegalDrop(board, flags, board[n][holdings], r, f);
1970 if(moveType == WhiteDrop || moveType == BlackDrop) return (inCheck ? MT_CHECK : MT_NONE); // we have legal drop
1973 if(gameInfo.variant == VariantSuicide) // [HGM] losers: always stalemate, since no check, but result varies
1974 return myPieces == hisPieces ? MT_STALEMATE :
1975 myPieces > hisPieces ? MT_STAINMATE : MT_STEALMATE;
1976 else if(gameInfo.variant == VariantLosers) return inCheck ? MT_TRICKMATE : MT_STEALMATE;
1977 else if(gameInfo.variant == VariantGiveaway) return MT_STEALMATE; // no check exists, stalemated = win
1979 return inCheck ? MT_CHECKMATE
1980 : (gameInfo.variant == VariantXiangqi || gameInfo.variant == VariantShatranj || IS_SHOGI(gameInfo.variant)) ?
1981 MT_STAINMATE : MT_STALEMATE;
1986 extern void DisambiguateCallback P((Board board, int flags, ChessMove kind,
1987 int rf, int ff, int rt, int ft,
1991 DisambiguateCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1993 register DisambiguateClosure *cl = (DisambiguateClosure *) closure;
1994 int wildCard = FALSE; ChessSquare piece = board[rf][ff];
1995 extern int kifu; // in parser.c
1997 // [HGM] wild: for wild-card pieces rt and rf are dummies
1998 if(piece == WhiteFalcon || piece == BlackFalcon ||
1999 piece == WhiteCobra || piece == BlackCobra)
2002 if ((cl->pieceIn == EmptySquare || cl->pieceIn == board[rf][ff]
2003 || PieceToChar(board[rf][ff]) == '~'
2004 && cl->pieceIn == (ChessSquare)(DEMOTED(board[rf][ff]))
2006 (cl->rfIn == -1 || cl->rfIn == rf) &&
2007 (cl->ffIn == -1 || cl->ffIn == ff) &&
2008 (cl->rtIn == -1 || cl->rtIn == rt || wildCard) &&
2009 (cl->ftIn == -1 || cl->ftIn == ft || wildCard)) {
2011 if(cl->count && rf == cl->rf && ff == cl->ff) return; // duplicate move
2013 if(cl->count == 1 && kifu & 0x7E && cl->rfIn == -1 && cl->ffIn == -1) { // traditional Shogi disambiguation required
2014 int this = 1, other = 1;
2015 if(kifu & 2) this &= (flags & 1 ? rt > rf : rt < rf), other &= (flags & 1 ? cl->rt > cl->rf : cl->rt < cl->rf);
2016 if(kifu & 4) this &= (flags & 1 ? rt < rf : rt > rf), other &= (flags & 1 ? cl->rt < cl->rf : cl->rt > cl->rf);
2017 if(kifu & 8) this &= (rf == rt), other &= (cl->rt == cl->rf);
2018 if(kifu & 0x10) this &= (flags & 1 ? ft <= ff : ft >= ff), other &= (flags & 1 ? cl->ft <= cl->ff : cl->ft >= cl->ff);
2019 if(kifu & 0x20) this &= (flags & 1 ? ft >= ff : ft <= ff), other &= (flags & 1 ? cl->ft >= cl->ff : cl->ft <= cl->ff);
2020 if(kifu & 0x40) this &= (ft == ff), other &= (cl->ft == cl->ff); // should never be used
2021 if(!other) cl->count--; // the old move did not satisfy the requested relative position, erase it
2022 if(!this) return; // the current move does not satisfy the requested relative position, ignore it
2026 if(cl->count == 1 || board[rt][ft] != EmptySquare) {
2027 // [HGM] oneclick: if multiple moves, be sure we remember capture
2028 cl->piece = board[rf][ff];
2031 cl->rt = wildCard ? cl->rtIn : rt;
2032 cl->ft = wildCard ? cl->ftIn : ft;
2035 cl->captures += (board[rt][ft] != EmptySquare); // [HGM] oneclick: count captures
2040 Disambiguate (Board board, int flags, DisambiguateClosure *closure)
2042 int illegal = 0; char c = closure->promoCharIn;
2044 if(quickFlag) flags = flags & ~1 | quickFlag & 1; // [HGM] speed: in quick mode quickFlag specifies side-to-move.
2045 closure->count = closure->captures = 0;
2046 closure->rf = closure->ff = closure->rt = closure->ft = 0;
2047 closure->kind = ImpossibleMove;
2048 rFilter = closure->rtIn; // [HGM] speed: only consider moves to given to-square
2049 fFilter = closure->ftIn;
2050 if(quickFlag) { // [HGM] speed: try without check test first, because if that is not ambiguous, we are happy
2051 GenLegal(board, flags|F_IGNORE_CHECK, DisambiguateCallback, (VOIDSTAR) closure, closure->pieceIn);
2052 if(closure->count > 1) { // gamble did not pay off. retry with check test to resolve ambiguity
2053 closure->count = closure->captures = 0;
2054 closure->rf = closure->ff = closure->rt = closure->ft = 0;
2055 closure->kind = ImpossibleMove;
2056 GenLegal(board, flags, DisambiguateCallback, (VOIDSTAR) closure, closure->pieceIn); // [HGM] speed: only pieces of requested type
2059 GenLegal(board, flags, DisambiguateCallback, (VOIDSTAR) closure, closure->pieceIn); // [HGM] speed: only pieces of requested type
2060 if (closure->count == 0) {
2061 /* See if it's an illegal move due to check */
2063 GenLegal(board, flags|F_IGNORE_CHECK, DisambiguateCallback, (VOIDSTAR) closure, closure->pieceIn);
2064 if (closure->count == 0) {
2065 /* No, it's not even that */
2066 if(!appData.testLegality && !pieceDefs && closure->pieceIn != EmptySquare) {
2067 int f, r; // if there is only a single piece of the requested type on the board, use that
2068 closure->rt = closure->rtIn, closure->ft = closure->ftIn;
2069 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++)
2070 if(board[r][f] == closure->pieceIn) closure->count++, closure->rf = r, closure->ff = f;
2071 if(closure->count > 1) illegal = 0; // ambiguous
2073 if(closure->count == 0) {
2074 if (appData.debugMode) { int i, j;
2075 for(i=BOARD_HEIGHT-1; i>=0; i--) {
2076 for(j=0; j<BOARD_WIDTH; j++)
2077 fprintf(debugFP, "%3d", (int) board[i][j]);
2078 fprintf(debugFP, "\n");
2084 } else if(pieceDefs && closure->count > 1) { // [HGM] gen: move is ambiguous under engine-defined rules
2085 DisambiguateClosure spare = *closure;
2086 pieceDefs = FALSE; spare.count = 0; // See if the (erroneous) built-in rules would resolve that
2087 GenLegal(board, flags, DisambiguateCallback, (VOIDSTAR) &spare, closure->pieceIn);
2088 if(spare.count == 1) *closure = spare; // It does, so use those in stead (game from file saved before gen patch?)
2092 if (c == 'x') c = NULLCHAR; // get rid of any 'x' (which should never happen?)
2093 if(gameInfo.variant == VariantSChess && c && c != '=' && closure->piece != WhitePawn && closure->piece != BlackPawn) {
2094 if(closure->piece < BlackPawn) { // white
2095 if(closure->rf != 0) closure->kind = IllegalMove; // must be on back rank
2096 if(!(board[VIRGIN][closure->ff] & VIRGIN_W)) closure->kind = IllegalMove; // non-virgin
2097 if(board[PieceToNumber(CharToPiece(ToUpper(c)))][BOARD_WIDTH-2] == 0) closure->kind = ImpossibleMove;// must be in stock
2098 if(closure->kind == WhiteHSideCastleFR && (closure->ff == BOARD_RGHT-2 || closure->ff == BOARD_RGHT-3)) closure->kind = ImpossibleMove;
2099 if(closure->kind == WhiteASideCastleFR && (closure->ff == BOARD_LEFT+2 || closure->ff == BOARD_LEFT+3)) closure->kind = ImpossibleMove;
2101 if(closure->rf != BOARD_HEIGHT-1) closure->kind = IllegalMove;
2102 if(!(board[VIRGIN][closure->ff] & VIRGIN_B)) closure->kind = IllegalMove; // non-virgin
2103 if(board[BOARD_HEIGHT-1-PieceToNumber(CharToPiece(ToLower(c)))][1] == 0) closure->kind = ImpossibleMove;
2104 if(closure->kind == BlackHSideCastleFR && (closure->ff == BOARD_RGHT-2 || closure->ff == BOARD_RGHT-3)) closure->kind = ImpossibleMove;
2105 if(closure->kind == BlackASideCastleFR && (closure->ff == BOARD_LEFT+2 || closure->ff == BOARD_LEFT+3)) closure->kind = ImpossibleMove;
2108 if(gameInfo.variant == VariantChu) {
2109 if(c == '+') closure->kind = (flags & F_WHITE_ON_MOVE ? WhitePromotion : BlackPromotion); // for now, accept any
2111 if(gameInfo.variant == VariantShogi) {
2112 /* [HGM] Shogi promotions. On input, '=' means defer, '+' promote. Afterwards, c is set to '+' for promotions, NULL other */
2113 if(closure->rfIn != DROP_RANK && closure->kind == NormalMove) {
2114 ChessSquare piece = closure->piece;
2115 int zone = BOARD_HEIGHT/3 + (BOARD_HEIGHT == 8);
2116 if (c == 'd' && (piece == WhiteRook || piece == BlackRook) ||
2117 c == 'h' && (piece == WhiteBishop || piece == BlackBishop) ||
2118 c == 'g' && (piece <= WhiteFerz || piece <= BlackFerz && piece >= BlackPawn) )
2119 c = '+'; // allowed ICS notations
2120 if(c != NULLCHAR && c != '+' && c != '=') closure->kind = IllegalMove; // otherwise specifying a piece is illegal
2121 else if(flags & F_WHITE_ON_MOVE) {
2122 if( (int) piece < (int) WhiteWazir &&
2123 (closure->rf >= BOARD_HEIGHT-zone || closure->rt >= BOARD_HEIGHT-zone) ) {
2124 if( (piece == WhitePawn || piece == WhiteQueen) && closure->rt > BOARD_HEIGHT-2 ||
2125 piece == WhiteKnight && closure->rt > BOARD_HEIGHT-3) /* promotion mandatory */
2126 closure->kind = c == '=' ? IllegalMove : WhitePromotion;
2127 else /* promotion optional, default is defer */
2128 closure->kind = c == '+' ? WhitePromotion : WhiteNonPromotion;
2129 } else closure->kind = c == '+' ? IllegalMove : NormalMove;
2131 if( (int) piece < (int) BlackWazir && (closure->rf < zone || closure->rt < zone) ) {
2132 if( (piece == BlackPawn || piece == BlackQueen) && closure->rt < 1 ||
2133 piece == BlackKnight && closure->rt < 2 ) /* promotion obligatory */
2134 closure->kind = c == '=' ? IllegalMove : BlackPromotion;
2135 else /* promotion optional, default is defer */
2136 closure->kind = c == '+' ? BlackPromotion : BlackNonPromotion;
2137 } else closure->kind = c == '+' ? IllegalMove : NormalMove;
2140 if(closure->kind == WhitePromotion || closure->kind == BlackPromotion) c = '+'; else
2141 if(closure->kind == WhiteNonPromotion || closure->kind == BlackNonPromotion) c = '=';
2143 if (closure->kind == WhitePromotion || closure->kind == BlackPromotion) {
2144 if(c == NULLCHAR) { // missing promoChar on mandatory promotion; use default for variant
2145 if(gameInfo.variant == VariantShatranj || gameInfo.variant == VariantCourier ||
2146 gameInfo.variant == VariantMakruk)
2147 c = PieceToChar(BlackFerz);
2148 else if(gameInfo.variant == VariantASEAN)
2149 c = PieceToChar(BlackRook);
2150 else if(gameInfo.variant == VariantGreat)
2151 c = PieceToChar(BlackMan);
2152 else if(gameInfo.variant == VariantGrand)
2153 closure->kind = closure->rt != 0 && closure->rt != BOARD_HEIGHT-1 ? NormalMove : AmbiguousMove; // no default in Grand Chess
2155 c = PieceToChar(BlackQueen);
2156 } else if(c == '=') closure->kind = IllegalMove; // no deferral outside Shogi
2157 else if(c == 'l' && gameInfo.variant == VariantChuChess && HasLion(board, flags)) closure->kind = IllegalMove;
2158 } else if (c == '+') { // '+' outside shogi, check if pieceToCharTable enabled it
2159 ChessSquare p = closure->piece;
2160 if(p > WhiteMan && p < BlackPawn || p > BlackMan || PieceToChar(PROMOTED(p)) != '+')
2161 closure->kind = ImpossibleMove; // used on non-promotable piece
2162 else if(gameInfo.variant == VariantChuChess && HasLion(board, flags)) closure->kind = IllegalMove;
2163 } else if (c != NULLCHAR) closure->kind = IllegalMove;
2165 closure->promoChar = ToLower(c); // this can be NULLCHAR! Note we keep original promoChar even if illegal.
2166 if(c != '+' && c != '=' && c != NULLCHAR && CharToPiece(flags & F_WHITE_ON_MOVE ? ToUpper(c) : ToLower(c)) == EmptySquare)
2167 closure->kind = ImpossibleMove; // but we cannot handle non-existing piece types!
2168 if (closure->count > 1) {
2169 closure->kind = AmbiguousMove;
2172 /* Note: If more than one illegal move matches, but no legal
2173 moves, we return IllegalMove, not AmbiguousMove. Caller
2174 can look at closure->count to detect this.
2176 closure->kind = IllegalMove;
2190 } CoordsToAlgebraicClosure;
2192 extern void CoordsToAlgebraicCallback P((Board board, int flags,
2193 ChessMove kind, int rf, int ff,
2194 int rt, int ft, VOIDSTAR closure));
2197 CoordsToAlgebraicCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
2199 register CoordsToAlgebraicClosure *cl =
2200 (CoordsToAlgebraicClosure *) closure;
2202 if ((rt == cl->rt && ft == cl->ft || rt == rf && ft == ff) && // [HGM] null move matches any toSquare
2203 (board[rf][ff] == cl->piece
2204 || PieceToChar(board[rf][ff]) == '~' &&
2205 (ChessSquare) (DEMOTED(board[rf][ff])) == cl->piece)
2209 cl->kind = kind; /* this is the move we want */
2211 cl->file++; /* need file to rule out this move */
2215 cl->rank++; /* need rank to rule out this move */
2217 cl->either++; /* rank or file will rule out this move */
2223 /* Convert coordinates to normal algebraic notation.
2224 promoChar must be NULLCHAR or 'x' if not a promotion.
2227 CoordsToAlgebraic (Board board, int flags, int rf, int ff, int rt, int ft, int promoChar, char out[MOVE_LEN])
2231 char *outp = out, c, capture;
2232 CoordsToAlgebraicClosure cl;
2234 if (rf == DROP_RANK) {
2235 if(ff == EmptySquare) { strncpy(outp, "--",3); return NormalMove; } // [HGM] pass
2236 /* Bughouse piece drop */
2237 *outp++ = ToUpper(PieceToChar((ChessSquare) ff));
2242 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2244 return (flags & F_WHITE_ON_MOVE) ? WhiteDrop : BlackDrop;
2247 if (promoChar == 'x') promoChar = NULLCHAR;
2248 piece = board[rf][ff];
2249 if(PieceToChar(piece)=='~') piece = (ChessSquare)(DEMOTED(piece));
2254 kind = LegalityTest(board, flags, rf, ff, rt, ft, promoChar);
2255 if (kind == IllegalMove && !(flags&F_IGNORE_CHECK)) {
2256 /* Keep short notation if move is illegal only because it
2257 leaves the player in check, but still return IllegalMove */
2258 kind = LegalityTest(board, flags|F_IGNORE_CHECK, rf, ff, rt, ft, promoChar);
2259 if (kind == IllegalMove) break;
2264 capture = board[rt][ft] != EmptySquare || kind == WhiteCapturesEnPassant || kind == BlackCapturesEnPassant;
2265 if (ff == ft && !capture) { /* [HGM] Xiangqi has straight noncapts! */
2266 /* Non-capture; use style "e5" */
2269 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2271 /* Capture; use style "exd5" */
2273 *outp++ = 'x'; /* [HGM] Xiangqi has sideway noncaptures across river! */
2277 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2279 /* Use promotion suffix style "=Q" */
2281 if (promoChar != NULLCHAR) {
2282 if(IS_SHOGI(gameInfo.variant)) {
2283 /* [HGM] ... but not in Shogi! */
2284 *outp++ = promoChar == '=' ? '=' : '+';
2287 *outp++ = ToUpper(promoChar);
2296 /* Fabien moved code: FRC castling first (if KxR), wild castling second */
2297 /* Code added by Tord: FRC castling. */
2298 if((piece == WhiteKing && board[rt][ft] == WhiteRook) ||
2299 (piece == BlackKing && board[rt][ft] == BlackRook)) {
2301 safeStrCpy(out, "O-O", MOVE_LEN);
2303 safeStrCpy(out, "O-O-O", MOVE_LEN);
2304 return LegalityTest(board, flags, rf, ff, rt, ft, promoChar);
2306 /* End of code added by Tord */
2307 /* Test for castling or ICS wild castling */
2308 /* Use style "O-O" (oh-oh) for PGN compatibility */
2309 else if (rf == rt &&
2310 rf == ((piece == WhiteKing) ? 0 : BOARD_HEIGHT-1) &&
2311 (ft - ff > 1 || ff - ft > 1) && // No castling if legal King move (on narrow boards!)
2312 ((ff == BOARD_WIDTH>>1 && (ft == BOARD_LEFT+2 || ft == BOARD_RGHT-2)) ||
2313 (ff == (BOARD_WIDTH-1)>>1 && (ft == BOARD_LEFT+1 || ft == BOARD_RGHT-3)))) {
2314 if(ft==BOARD_LEFT+1 || ft==BOARD_RGHT-2)
2315 snprintf(out, MOVE_LEN, "O-O%c%c", promoChar ? '/' : 0, ToUpper(promoChar));
2317 snprintf(out, MOVE_LEN, "O-O-O%c%c", promoChar ? '/' : 0, ToUpper(promoChar));
2319 /* This notation is always unambiguous, unless there are
2320 kings on both the d and e files, with "wild castling"
2321 possible for the king on the d file and normal castling
2322 possible for the other. ICS rules for wild 9
2323 effectively make castling illegal for either king in
2324 this situation. So I am not going to worry about it;
2325 I'll just generate an ambiguous O-O in this case.
2327 return LegalityTest(board, flags, rf, ff, rt, ft, promoChar);
2330 /* else fall through */
2335 cl.rt = rFilter = rt; // [HGM] speed: filter on to-square
2336 cl.ft = fFilter = ft;
2338 cl.kind = IllegalMove;
2339 cl.rank = cl.file = cl.either = 0;
2340 c = PieceToChar(piece) ;
2341 GenLegal(board, flags, CoordsToAlgebraicCallback, (VOIDSTAR) &cl, c!='~' ? piece : (DEMOTED(piece))); // [HGM] speed
2343 if (cl.kind == IllegalMove && !(flags&F_IGNORE_CHECK)) {
2344 /* Generate pretty moves for moving into check, but
2345 still return IllegalMove.
2347 GenLegal(board, flags|F_IGNORE_CHECK, CoordsToAlgebraicCallback, (VOIDSTAR) &cl, c!='~' ? piece : (DEMOTED(piece)));
2348 if (cl.kind == IllegalMove) break;
2349 cl.kind = IllegalMove;
2352 /* Style is "Nf3" or "Nxf7" if this is unambiguous,
2353 else "Ngf3" or "Ngxf7",
2354 else "N1f3" or "N5xf7",
2355 else "Ng1f3" or "Ng5xf7".
2357 if( c == '~' || c == '+') {
2358 /* [HGM] print nonexistent piece as its demoted version */
2359 piece = (ChessSquare) (CHUDEMOTED(piece));
2361 if(c=='+') *outp++ = c;
2362 *outp++ = ToUpper(PieceToChar(piece));
2363 if(*outp = PieceSuffix(piece)) outp++;
2365 if (cl.file || (cl.either && !cl.rank)) {
2371 else { *outp++ = (rf+ONE-'0')/10 + '0';*outp++ = (rf+ONE-'0')%10 + '0'; }
2374 if(board[rt][ft] != EmptySquare)
2380 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2381 if (IS_SHOGI(gameInfo.variant)) {
2382 /* [HGM] in Shogi non-pawns can promote */
2383 *outp++ = promoChar; // Don't bother to correct move type, return value is never used!
2385 else if (gameInfo.variant == VariantChuChess && promoChar ||
2386 gameInfo.variant != VariantSuper && promoChar &&
2387 (piece == WhiteLance || piece == BlackLance) ) { // Lance sometimes represents Pawn
2389 *outp++ = ToUpper(promoChar);
2391 else if (gameInfo.variant == VariantSChess && promoChar) { // and in S-Chess we have gating
2393 *outp++ = ToUpper(promoChar);
2399 /* Moving a nonexistent piece */
2403 /* Not a legal move, even ignoring check.
2404 If there was a piece on the from square,
2405 use style "Ng1g3" or "Ng1xe8";
2406 if there was a pawn or nothing (!),
2407 use style "g1g3" or "g1xe8". Use "x"
2408 if a piece was on the to square, even
2409 a piece of the same color.
2413 if (piece != EmptySquare && piece != WhitePawn && piece != BlackPawn) {
2415 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<=BOARD_RGHT; f++)
2416 c += (board[r][f] == piece); // count on-board pieces of given type
2417 *outp++ = ToUpper(PieceToChar(piece));
2419 if(c != 1) { // [HGM] but if there is only one piece of the mentioned type, no from-square, thank you!
2423 else { *outp++ = (rf+ONE-'0')/10 + '0';*outp++ = (rf+ONE-'0')%10 + '0'; }
2425 if (board[rt][ft] != EmptySquare) *outp++ = 'x';
2429 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2430 /* Use promotion suffix style "=Q" */
2431 if (promoChar != NULLCHAR && promoChar != 'x') {
2433 *outp++ = ToUpper(promoChar);
2440 // [HGM] XQ: the following code serves to detect perpetual chasing (Asian rules)
2449 // I guess the following variables logically belong in the closure too, but I was too lazy and used globals
2451 int preyStackPointer, chaseStackPointer;
2454 unsigned char rf, ff, rt, ft;
2458 unsigned char rank, file;
2464 // there are three new callbacks for use with GenLegal: for adding captures, deleting them, and finding a recapture
2466 extern void AtacksCallback P((Board board, int flags, ChessMove kind,
2467 int rf, int ff, int rt, int ft,
2471 AttacksCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
2472 { // For adding captures that can lead to chase indictment to the chaseStack
2473 if(board[rt][ft] == EmptySquare) return; // non-capture
2474 if(board[rt][ft] == WhitePawn && rt < BOARD_HEIGHT/2) return; // Pawn before river can be chased
2475 if(board[rt][ft] == BlackPawn && rt >= BOARD_HEIGHT/2) return; // Pawn before river can be chased
2476 if(board[rf][ff] == WhitePawn || board[rf][ff] == BlackPawn) return; // Pawns are allowed to chase
2477 if(board[rf][ff] == WhiteWazir || board[rf][ff] == BlackWazir) return; // King is allowed to chase
2478 // move cannot be excluded from being a chase trivially (based on attacker and victim); save it on chaseStack
2479 chaseStack[chaseStackPointer].rf = rf;
2480 chaseStack[chaseStackPointer].ff = ff;
2481 chaseStack[chaseStackPointer].rt = rt;
2482 chaseStack[chaseStackPointer].ft = ft;
2483 chaseStackPointer++;
2486 extern void ExistingAtacksCallback P((Board board, int flags, ChessMove kind,
2487 int rf, int ff, int rt, int ft,
2491 ExistingAttacksCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
2492 { // for removing pre-exsting captures from the chaseStack, to be left with newly created ones
2494 register ChaseClosure *cl = (ChaseClosure *) closure; //closure tells us the move played in the repeat loop
2496 if(board[rt][ft] == EmptySquare) return; // no capture
2497 if(rf == cl->rf && ff == cl->ff) { // attacks with same piece from new position are not considered new
2498 rf = cl->rt; ff = cl->ft; // doctor their fromSquare so they will be recognized in chaseStack
2500 // search move in chaseStack, and delete it if it occurred there (as we know now it is not a new capture)
2501 for(i=0; i<chaseStackPointer; i++) {
2502 if(chaseStack[i].rf == rf && chaseStack[i].ff == ff &&
2503 chaseStack[i].rt == rt && chaseStack[i].ft == ft ) {
2504 // move found on chaseStack, delete it by overwriting with move popped from top of chaseStack
2505 chaseStack[i] = chaseStack[--chaseStackPointer];
2511 extern void ProtectedCallback P((Board board, int flags, ChessMove kind,
2512 int rf, int ff, int rt, int ft,
2516 ProtectedCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
2517 { // for determining if a piece (given through the closure) is protected
2518 register ChaseClosure *cl = (ChaseClosure *) closure; // closure tells us where to recapture
2520 if(rt == cl->rt && ft == cl->ft) cl->recaptures++; // count legal recaptures to this square
2521 if(appData.debugMode && board[rt][ft] != EmptySquare)
2522 fprintf(debugFP, "try %c%c%c%c=%d\n", ff+AAA, rf+ONE,ft+AAA, rt+ONE, cl->recaptures);
2525 extern char moveList[MAX_MOVES][MOVE_LEN];
2528 PerpetualChase (int first, int last)
2529 { // this routine detects if the side to move in the 'first' position is perpetually chasing (when not checking)
2532 ChessSquare captured;
2534 preyStackPointer = 0; // clear stack of chased pieces
2535 for(i=first; i<last; i+=2) { // for all positions with same side to move
2536 if(appData.debugMode) fprintf(debugFP, "judge position %i\n", i);
2537 chaseStackPointer = 0; // clear stack that is going to hold possible chases
2538 // determine all captures possible after the move, and put them on chaseStack
2539 GenLegal(boards[i+1], PosFlags(i), AttacksCallback, &cl, EmptySquare);
2540 if(appData.debugMode) { int n;
2541 for(n=0; n<chaseStackPointer; n++)
2542 fprintf(debugFP, "%c%c%c%c ", chaseStack[n].ff+AAA, chaseStack[n].rf+ONE,
2543 chaseStack[n].ft+AAA, chaseStack[n].rt+ONE);
2544 fprintf(debugFP, ": all capts\n");
2546 // determine all captures possible before the move, and delete them from chaseStack
2547 cl.rf = moveList[i][1]-ONE; // prepare closure to pass move that led from i to i+1
2548 cl.ff = moveList[i][0]-AAA+BOARD_LEFT;
2549 cl.rt = moveList[i][3]-ONE;
2550 cl.ft = moveList[i][2]-AAA+BOARD_LEFT;
2551 CopyBoard(xqCheckers, nullBoard); xqCheckers[EP_STATUS] = 1; // giant kludge to make GenLegal ignore pre-existing checks
2552 GenLegal(boards[i], PosFlags(i), ExistingAttacksCallback, &cl, EmptySquare);
2553 xqCheckers[EP_STATUS] = 0; // disable the generation of quasi-legal moves again
2554 if(appData.debugMode) { int n;
2555 for(n=0; n<chaseStackPointer; n++)
2556 fprintf(debugFP, "%c%c%c%c ", chaseStack[n].ff+AAA, chaseStack[n].rf+ONE,
2557 chaseStack[n].ft+AAA, chaseStack[n].rt+ONE);
2558 fprintf(debugFP, ": new capts after %c%c%c%c\n", cl.ff+AAA, cl.rf+ONE, cl.ft+AAA, cl.rt+ONE);
2560 // chaseSack now contains all captures made possible by the move
2561 for(j=0; j<chaseStackPointer; j++) { // run through chaseStack to identify true chases
2562 int attacker = (int)boards[i+1][chaseStack[j].rf][chaseStack[j].ff];
2563 int victim = (int)boards[i+1][chaseStack[j].rt][chaseStack[j].ft];
2565 if(attacker >= (int) BlackPawn) attacker = BLACK_TO_WHITE attacker; // convert to white, as piecee type
2566 if(victim >= (int) BlackPawn) victim = BLACK_TO_WHITE victim;
2568 if((attacker == WhiteKnight || attacker == WhiteCannon) && victim == WhiteRook)
2569 continue; // C or H attack on R is always chase; leave on chaseStack
2571 if(attacker == victim) {
2572 if(LegalityTest(boards[i+1], PosFlags(i+1), chaseStack[j].rt,
2573 chaseStack[j].ft, chaseStack[j].rf, chaseStack[j].ff, NULLCHAR) == NormalMove) {
2574 // we can capture back with equal piece, so this is no chase but a sacrifice
2575 chaseStack[j] = chaseStack[--chaseStackPointer]; // delete the capture from the chaseStack
2576 j--; /* ! */ continue;
2581 // the attack is on a lower piece, or on a pinned or blocked equal one
2582 CopyBoard(xqCheckers, nullBoard); xqCheckers[EP_STATUS] = 1;
2583 CheckTest(boards[i+1], PosFlags(i+1), -1, -1, -1, -1, FALSE); // if we deliver check with our move, the checkers get marked
2584 // test if the victim is protected by a true protector. First make the capture.
2585 captured = boards[i+1][chaseStack[j].rt][chaseStack[j].ft];
2586 boards[i+1][chaseStack[j].rt][chaseStack[j].ft] = boards[i+1][chaseStack[j].rf][chaseStack[j].ff];
2587 boards[i+1][chaseStack[j].rf][chaseStack[j].ff] = EmptySquare;
2588 // Then test if the opponent can recapture
2589 cl.recaptures = 0; // prepare closure to pass recapture square and count moves to it
2590 cl.rt = chaseStack[j].rt;
2591 cl.ft = chaseStack[j].ft;
2592 if(appData.debugMode) {
2593 fprintf(debugFP, "test if we can recapture %c%c\n", cl.ft+AAA, cl.rt+ONE);
2595 xqCheckers[EP_STATUS] = 2; // causes GenLegal to ignore the checks we delivered with the move, in real life evaded before we captured
2596 GenLegal(boards[i+1], PosFlags(i+1), ProtectedCallback, &cl, EmptySquare); // try all moves
2597 xqCheckers[EP_STATUS] = 0; // disable quasi-legal moves again
2598 // unmake the capture
2599 boards[i+1][chaseStack[j].rf][chaseStack[j].ff] = boards[i+1][chaseStack[j].rt][chaseStack[j].ft];
2600 boards[i+1][chaseStack[j].rt][chaseStack[j].ft] = captured;
2601 // if a recapture was found, piece is protected, and we are not chasing it.
2602 if(cl.recaptures) { // attacked piece was defended by true protector, no chase
2603 chaseStack[j] = chaseStack[--chaseStackPointer]; // so delete from chaseStack
2607 // chaseStack now contains all moves that chased
2608 if(appData.debugMode) { int n;
2609 for(n=0; n<chaseStackPointer; n++)
2610 fprintf(debugFP, "%c%c%c%c ", chaseStack[n].ff+AAA, chaseStack[n].rf+ONE,
2611 chaseStack[n].ft+AAA, chaseStack[n].rt+ONE);
2612 fprintf(debugFP, ": chases\n");
2614 if(i == first) { // copy all people chased by first move of repeat cycle to preyStack
2615 for(j=0; j<chaseStackPointer; j++) {
2616 preyStack[j].rank = chaseStack[j].rt;
2617 preyStack[j].file = chaseStack[j].ft;
2619 preyStackPointer = chaseStackPointer;
2622 for(j=0; j<chaseStackPointer; j++) {
2623 for(k=0; k<preyStackPointer; k++) {
2624 // search the victim of each chase move on the preyStack (first occurrence)
2625 if(chaseStack[j].ft == preyStack[k].file && chaseStack[j].rt == preyStack[k].rank ) {
2626 if(k < tail) break; // piece was already identified as still being chased
2627 preyStack[preyStackPointer] = preyStack[tail]; // move chased piece to bottom part of preyStack
2628 preyStack[tail] = preyStack[k]; // by swapping
2629 preyStack[k] = preyStack[preyStackPointer];
2635 preyStackPointer = tail; // keep bottom part of preyStack, popping pieces unchased on move i.
2636 if(appData.debugMode) { int n;
2637 for(n=0; n<preyStackPointer; n++)
2638 fprintf(debugFP, "%c%c ", preyStack[n].file+AAA, preyStack[n].rank+ONE);
2639 fprintf(debugFP, "always chased upto ply %d\n", i);
2641 // now adjust the location of the chased pieces according to opponent move
2642 for(j=0; j<preyStackPointer; j++) {
2643 if(preyStack[j].rank == moveList[i+1][1]-ONE &&
2644 preyStack[j].file == moveList[i+1][0]-AAA+BOARD_LEFT) {
2645 preyStack[j].rank = moveList[i+1][3]-ONE;
2646 preyStack[j].file = moveList[i+1][2]-AAA+BOARD_LEFT;
2651 return preyStackPointer ? 256*(preyStack[preyStackPointer].file - BOARD_LEFT + AAA) + (preyStack[preyStackPointer].rank + ONE)
2652 : 0; // if any piece was left on preyStack, it has been perpetually chased,and we return the