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 Free Software Foundation, Inc.
10 * Enhancements Copyright 2005 Alessandro Scotti
12 * The following terms apply to Digital Equipment Corporation's copyright
14 * ------------------------------------------------------------------------
17 * Permission to use, copy, modify, and distribute this software and its
18 * documentation for any purpose and without fee is hereby granted,
19 * provided that the above copyright notice appear in all copies and that
20 * both that copyright notice and this permission notice appear in
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22 * used in advertising or publicity pertaining to distribution of the
23 * software without specific, written prior permission.
25 * DIGITAL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING
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29 * WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
30 * ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
32 * ------------------------------------------------------------------------
34 * The following terms apply to the enhanced version of XBoard
35 * distributed by the Free Software Foundation:
36 * ------------------------------------------------------------------------
38 * GNU XBoard is free software: you can redistribute it and/or modify
39 * it under the terms of the GNU General Public License as published by
40 * the Free Software Foundation, either version 3 of the License, or (at
41 * your option) any later version.
43 * GNU XBoard is distributed in the hope that it will be useful, but
44 * WITHOUT ANY WARRANTY; without even the implied warranty of
45 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
46 * General Public License for more details.
48 * You should have received a copy of the GNU General Public License
49 * along with this program. If not, see http://www.gnu.org/licenses/. *
51 *------------------------------------------------------------------------
52 ** See the file ChangeLog for a revision history. */
61 #else /* not HAVE_STRING_H */
63 #endif /* not HAVE_STRING_H */
69 int WhitePiece P((ChessSquare));
70 int BlackPiece P((ChessSquare));
71 int SameColor P((ChessSquare, ChessSquare));
72 int PosFlags(int index);
74 extern signed char initialRights[BOARD_FILES]; /* [HGM] all rights enabled, set in InitPosition */
76 char *pieceDesc[EmptySquare];
77 char *defaultDesc[EmptySquare] = {
78 "fmWfceFifmnD", "N", "B", "R", "Q",
79 "F", "A", "BN", "RN", "W", "K",
80 "mRcpR", "N0", "BW", "RF", "gQ",
81 "", "", "QN", "", "N", "",
83 "", "", "", "", "", "",
85 "", "", "", "", "", "K"
89 WhitePiece (ChessSquare piece)
91 return (int) piece >= (int) WhitePawn && (int) piece < (int) BlackPawn;
95 BlackPiece (ChessSquare piece)
97 return (int) piece >= (int) BlackPawn && (int) piece < (int) EmptySquare;
102 SameColor (ChessSquare piece1, ChessSquare piece2)
104 return ((int) piece1 >= (int) WhitePawn && /* [HGM] can be > King ! */
105 (int) piece1 < (int) BlackPawn &&
106 (int) piece2 >= (int) WhitePawn &&
107 (int) piece2 < (int) BlackPawn)
108 || ((int) piece1 >= (int) BlackPawn &&
109 (int) piece1 < (int) EmptySquare &&
110 (int) piece2 >= (int) BlackPawn &&
111 (int) piece2 < (int) EmptySquare);
114 #define SameColor(piece1, piece2) (piece1 < EmptySquare && piece2 < EmptySquare && (piece1 < BlackPawn) == (piece2 < BlackPawn) || piece1 == DarkSquare || piece2 == DarkSquare)
117 unsigned char pieceToChar[EmptySquare+1] = {
118 'P', 'N', 'B', 'R', 'Q', 'F', 'E', 'A', 'C', 'W', 'M',
119 'O', 'H', 'I', 'J', 'G', 'D', 'V', 'L', 'S', 'U', 'K',
120 'p', 'n', 'b', 'r', 'q', 'f', 'e', 'a', 'c', 'w', 'm',
121 'o', 'h', 'i', 'j', 'g', 'd', 'v', 'l', 's', 'u', 'k',
123 unsigned char pieceNickName[EmptySquare];
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 if(*p == 'i') initial = 1, 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 && (board[r][f] != initialPosition[r][f] ||
376 r == 0 && board[TOUCHED_W] & 1<<f ||
377 r == BOARD_HEIGHT-1 && board[TOUCHED_B] & 1<<f ) ) continue;
378 if(expo > 1 && dx == 0 && dy == 0) { // castling indicated by O + number
379 mode |= 1024; dy = 1;
382 if(!(mode & 15)) mode |= his + 4; // no mode spec, use default = mc
384 strncpy(buf, cont, 80); cont = buf; // copy next leg(s), so we can modify
385 atom = buf; while(islower(*atom)) atom++; // skip to atom
386 if(mode & 32) mode ^= 256 + 32; // in non-final legs 'p' means 'pass through'
387 if(mode & 64 + 512) {
388 mode |= 256; // and 'g' too, but converts leaper <-> slider
389 if(mode & 512) mode ^= 0x304; // and 'y' is m-like 'g'
390 *atom = upgrade[*atom-'A']; // replace atom, BRQ <-> FWK
391 atom[1] = atom[2] = '\0'; // make sure any old range is stripped off
392 if(expo == 1) atom[1] = '0'; // turn other leapers into riders
394 if(!(mode & 0x30F)) mode |= 4; // and default of this leg = m
396 if(dy == 1) skip = jump - 1, jump = 1; // on W & F atoms 'j' = skip first square
398 for(dir=0, bit=1; dir<8; dir++, bit += bit) { // loop over directions
399 int i = expo, j = skip, hop = mode, vx, vy, loop = 0;
400 if(!(bit & dirSet)) continue; // does not move in this direction
401 if(dy != 1 || mode & 1024) j = 0; //
402 vx = dx*rot[dir][0] + dy*rot[dir][1]; // rotate step vector
403 vy = dx*rot[dir][2] + dy*rot[dir][3];
404 if(tx < 0) x = f, y = r; // start square
405 else x = tx, y = ty; // from previous to-square if continuation
407 x += vx; y += vy; // step to next square
408 if(y < 0 || y >= BOARD_HEIGHT) break; // vertically off-board: always done
409 if(x < BOARD_LEFT) { if(mode & 128) x += BOARD_RGHT - BOARD_LEFT, loop++; else break; }
410 if(x >= BOARD_RGHT) { if(mode & 128) x -= BOARD_RGHT - BOARD_LEFT, loop++; else break; }
411 if(board[y][x] == DarkSquare) break; // black squares are supposed to be off board
412 if(j) { j--; continue; } // skip irrespective of occupation
413 if(!jump && board[y - vy + vy/2][x - vx + vx/2] != EmptySquare) break; // blocked
414 if(jump > 1 && board[y - vy + vy/2][x - vx + vx/2] == EmptySquare) break; // no hop
415 if(x == f && y == r && !loop) occup = 4; else // start square counts as empty (if not around cylinder!)
416 if(board[y][x] < BlackPawn) occup = 0x101; else
417 if(board[y][x] < EmptySquare) occup = 0x102; else
419 if(cont) { // non-final leg
420 if(mode&16 && his&occup) occup &= 3;// suppress hopping foe in t-mode
421 if(occup & mode) { // valid intermediate square, do continuation
422 char origAtom = *atom;
423 if(!(bit & all)) *atom = rotate[*atom - 'A']; // orth-diag interconversion to make direction valid
424 if(occup & mode & 0x104) // no side effects, merge legs to one move
425 MovesFromString(board, flags, f, r, x, y, dir, cont, cb, cl);
426 if(occup & mode & 3 && (killX < 0 || killX == x && killY == y)) { // destructive first leg
428 MovesFromString(board, flags, f, r, x, y, dir, cont, &OK, &cnt); // count possible continuations
429 if(cnt) { // and if there are
430 if(killX < 0) cb(board, flags, FirstLeg, r, f, y, x, cl); // then generate their first leg
432 MovesFromString(board, flags, f, r, x, y, dir, cont, cb, cl);
436 *atom = origAtom; // undo any interconversion
438 if(occup != 4) break; // occupied squares always terminate the leg
441 if(hop & 32+64) { if(occup != 4) { if(hop & 64 && i != 1) i = 2; hop &= 31; } continue; } // hopper
443 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)
444 cb(board, flags, mine == 1 ? WhiteCapturesEnPassant : BlackCapturesEnPassant, r, f, y, x, cl);
446 if(mode & 1024) { // castling
447 i = 2; // kludge to elongate move indefinitely
448 if(occup == 4) continue; // skip empty squares
449 if((x == BOARD_LEFT + skip || x > BOARD_LEFT + skip && vx < 0 && board[y][x-1-skip] == DarkSquare)
450 && board[y][x] == initialPosition[y][x]) { // reached initial corner piece
451 if(pc != WhiteKing && pc != BlackKing) { // non-royal castling (to be entered as two-leg move via 'Rook')
452 if(killX < 0) cb(board, flags, FirstLeg, r, f, y, x, cl); if(killX < f)
453 legNr <<= 1, cb(board, flags, NormalMove, r, f, y, f - expo, cl), legNr >>= 1;
455 cb(board, flags, mine == 1 ? WhiteQueenSideCastle : BlackQueenSideCastle, r, f, y, f - expo, cl);
457 if((x == BOARD_RGHT-1-skip || x < BOARD_RGHT-1-skip && vx > 0 && board[y][x+1+skip] == DarkSquare)
458 && board[y][x] == initialPosition[y][x]) {
459 if(pc != WhiteKing && pc != BlackKing) {
460 if(killX < 0) cb(board, flags, FirstLeg, r, f, y, x, cl); if(killX > f)
461 legNr <<= 1, cb(board, flags, NormalMove, r, f, y, f + expo, cl), legNr >>= 1;
463 cb(board, flags, mine == 1 ? WhiteKingSideCastle : BlackKingSideCastle, r, f, y, f + expo, cl);
467 if(mode & 16 && (board[y][x] == WhiteKing || board[y][x] == BlackKing)) break; // tame piece, cannot capture royal
468 if(occup & mode) cb(board, flags, y == promoRank ? promo : NormalMove, r, f, y, x, cl); // allowed, generate
469 if(occup != 4) break; // not valid transit square
472 dx = dy; dirSet = ds2; // prepare for diagonal moves of K,Q
473 } while(retry-- && ds2); // and start doing them
474 if(tx >= 0) break; // don't do other atoms in continuation legs
478 // [HGM] move generation now based on hierarchy of subroutines for rays and combinations of rays
481 SlideForward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
486 if (rt >= BOARD_HEIGHT) break;
487 if (SameColor(board[rf][ff], board[rt][ft])) break;
488 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
489 if (board[rt][ft] != EmptySquare) break;
494 SlideBackward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
500 if (SameColor(board[rf][ff], board[rt][ft])) break;
501 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
502 if (board[rt][ft] != EmptySquare) break;
507 SlideVertical (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
509 SlideForward(board, flags, rf, ff, callback, closure);
510 SlideBackward(board, flags, rf, ff, callback, closure);
514 SlideSideways (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
516 int i, s, rt = rf, ft;
517 for(s = -1; s <= 1; s+= 2) {
520 if (ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
521 if (SameColor(board[rf][ff], board[rt][ft])) break;
522 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
523 if (board[rt][ft] != EmptySquare) break;
529 SlideDiagForward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
532 for(s = -1; s <= 1; s+= 2) {
536 if (rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
537 if (SameColor(board[rf][ff], board[rt][ft])) break;
538 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
539 if (board[rt][ft] != EmptySquare) break;
545 SlideDiagBackward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
548 for(s = -1; s <= 1; s+= 2) {
552 if (rt < 0 || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
553 if (SameColor(board[rf][ff], board[rt][ft])) break;
554 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
555 if (board[rt][ft] != EmptySquare) break;
561 Rook (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
563 SlideVertical(board, flags, rf, ff, callback, closure);
564 SlideSideways(board, flags, rf, ff, callback, closure);
568 Bishop (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
570 SlideDiagForward(board, flags, rf, ff, callback, closure);
571 SlideDiagBackward(board, flags, rf, ff, callback, closure);
575 Sting (Board board, int flags, int rf, int ff, int dy, int dx, MoveCallback callback, VOIDSTAR closure)
576 { // Lion-like move of Horned Falcon and Souring Eagle
577 int ft = ff + dx, rt = rf + dy;
578 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) return;
580 if (!SameColor(board[rf][ff], board[rt][ft]))
581 callback(board, flags, board[rt][ft] != EmptySquare ? FirstLeg : NormalMove, rf, ff, rt, ft, closure);
584 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) return;
586 if (!SameColor(board[rf][ff], board[rt][ft]))
587 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
588 if (!SameColor(board[rf][ff], board[rf+dy][ff+dx]))
589 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
594 StepForward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
596 int ft = ff, rt = rf + 1;
597 if (rt >= BOARD_HEIGHT) return;
598 if (SameColor(board[rf][ff], board[rt][ft])) return;
599 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
603 StepBackward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
605 int ft = ff, rt = rf - 1;
607 if (SameColor(board[rf][ff], board[rt][ft])) return;
608 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
612 StepSideways (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
616 if (!(rt >= BOARD_HEIGHT || ft >= BOARD_RGHT) && !SameColor(board[rf][ff], board[rt][ft]))
617 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
619 if (!(rt >= BOARD_HEIGHT || ft < BOARD_LEFT) && !SameColor(board[rf][ff], board[rt][ft]))
620 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
624 StepDiagForward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
627 if (rt >= BOARD_HEIGHT) return;
629 if (!(rt >= BOARD_HEIGHT || ft >= BOARD_RGHT) && !SameColor(board[rf][ff], board[rt][ft]))
630 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
632 if (!(rt >= BOARD_HEIGHT || ft < BOARD_LEFT) && !SameColor(board[rf][ff], board[rt][ft]))
633 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
637 StepDiagBackward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
642 if (!(rt < 0 || ft >= BOARD_RGHT) && !SameColor(board[rf][ff], board[rt][ft]))
643 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
645 if (!(rt < 0 || ft < BOARD_LEFT) && !SameColor(board[rf][ff], board[rt][ft]))
646 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
650 StepVertical (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
652 StepForward(board, flags, rf, ff, callback, closure);
653 StepBackward(board, flags, rf, ff, callback, closure);
657 Ferz (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
659 StepDiagForward(board, flags, rf, ff, callback, closure);
660 StepDiagBackward(board, flags, rf, ff, callback, closure);
664 Wazir (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
666 StepVertical(board, flags, rf, ff, callback, closure);
667 StepSideways(board, flags, rf, ff, callback, closure);
671 Knight (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
674 for (i = -1; i <= 1; i += 2)
675 for (j = -1; j <= 1; j += 2)
676 for (s = 1; s <= 2; s++) {
679 if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
680 && ( gameInfo.variant != VariantXiangqi || board[rf+i*(s-1)][ff+j*(2-s)] == EmptySquare)
681 && !SameColor(board[rf][ff], board[rt][ft]))
682 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
686 /* Call callback once for each pseudo-legal move in the given
687 position, except castling moves. A move is pseudo-legal if it is
688 legal, or if it would be legal except that it leaves the king in
689 check. In the arguments, epfile is EP_NONE if the previous move
690 was not a double pawn push, or the file 0..7 if it was, or
691 EP_UNKNOWN if we don't know and want to allow all e.p. captures.
692 Promotion moves generated are to Queen only.
695 GenPseudoLegal (Board board, int flags, MoveCallback callback, VOIDSTAR closure, ChessSquare filter)
696 // speed: only do moves with this piece type
699 int i, j, d, s, fs, rs, rt, ft, m;
700 int epfile = (signed char)board[EP_STATUS]; // [HGM] gamestate: extract ep status from board
701 int promoRank = gameInfo.variant == VariantMakruk || gameInfo.variant == VariantGrand || gameInfo.variant == VariantChuChess ? 3 : 1;
703 for (rf = 0; rf < BOARD_HEIGHT; rf++)
704 for (ff = BOARD_LEFT; ff < BOARD_RGHT; ff++) {
707 if(board[rf][ff] == EmptySquare) continue;
708 if ((flags & F_WHITE_ON_MOVE) != (board[rf][ff] < BlackPawn)) continue; // [HGM] speed: wrong color
709 m = 0; piece = board[rf][ff];
710 if(PieceToChar(piece) == '~')
711 piece = (ChessSquare) ( DEMOTED piece );
712 if(filter != EmptySquare && piece != filter) continue;
713 if(pieceDefs && pieceDesc[piece]) { // [HGM] gen: use engine-defined moves
714 MovesFromString(board, flags, ff, rf, -1, -1, 0, pieceDesc[piece], callback, closure);
717 if(IS_SHOGI(gameInfo.variant))
718 piece = (ChessSquare) ( SHOGI piece );
720 switch ((int)piece) {
721 /* case EmptySquare: [HGM] this is nonsense, and conflicts with Shogi cases */
723 /* can't happen ([HGM] except for faries...) */
727 if(gameInfo.variant == VariantXiangqi) {
728 /* [HGM] capture and move straight ahead in Xiangqi */
729 if (rf < BOARD_HEIGHT-1 &&
730 !SameColor(board[rf][ff], board[rf + 1][ff]) ) {
731 callback(board, flags, NormalMove,
732 rf, ff, rf + 1, ff, closure);
734 /* and move sideways when across the river */
735 for (s = -1; s <= 1; s += 2) {
736 if (rf >= BOARD_HEIGHT>>1 &&
737 ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
738 !WhitePiece(board[rf][ff+s]) ) {
739 callback(board, flags, NormalMove,
740 rf, ff, rf, ff+s, closure);
745 if (rf < BOARD_HEIGHT-1 && board[rf + 1][ff] == EmptySquare) {
746 callback(board, flags,
747 rf >= BOARD_HEIGHT-1-promoRank ? WhitePromotion : NormalMove,
748 rf, ff, rf + 1, ff, closure);
750 if (rf <= (BOARD_HEIGHT>>1)-3 && board[rf+1][ff] == EmptySquare && // [HGM] grand: also on 3rd rank on 10-board
751 gameInfo.variant != VariantShatranj && /* [HGM] */
752 gameInfo.variant != VariantCourier && /* [HGM] */
753 board[rf+2][ff] == EmptySquare ) {
754 callback(board, flags, NormalMove,
755 rf, ff, rf+2, ff, closure);
757 for (s = -1; s <= 1; s += 2) {
758 if (rf < BOARD_HEIGHT-1 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
759 ((flags & F_KRIEGSPIEL_CAPTURE) ||
760 BlackPiece(board[rf + 1][ff + s]))) {
761 callback(board, flags,
762 rf >= BOARD_HEIGHT-1-promoRank ? WhitePromotion : NormalMove,
763 rf, ff, rf + 1, ff + s, closure);
765 if (rf >= BOARD_HEIGHT+1>>1) {// [HGM] grand: 4th & 5th rank on 10-board
766 if (ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
767 (epfile == ff + s || epfile == EP_UNKNOWN) && rf < BOARD_HEIGHT-3 &&
768 board[rf][ff + s] == BlackPawn &&
769 board[rf+1][ff + s] == EmptySquare) {
770 callback(board, flags, WhiteCapturesEnPassant,
771 rf, ff, rf+1, ff + s, closure);
778 if(gameInfo.variant == VariantXiangqi) {
779 /* [HGM] capture straight ahead in Xiangqi */
780 if (rf > 0 && !SameColor(board[rf][ff], board[rf - 1][ff]) ) {
781 callback(board, flags, NormalMove,
782 rf, ff, rf - 1, ff, closure);
784 /* and move sideways when across the river */
785 for (s = -1; s <= 1; s += 2) {
786 if (rf < BOARD_HEIGHT>>1 &&
787 ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
788 !BlackPiece(board[rf][ff+s]) ) {
789 callback(board, flags, NormalMove,
790 rf, ff, rf, ff+s, closure);
795 if (rf > 0 && board[rf - 1][ff] == EmptySquare) {
796 callback(board, flags,
797 rf <= promoRank ? BlackPromotion : NormalMove,
798 rf, ff, rf - 1, ff, closure);
800 if (rf >= (BOARD_HEIGHT+1>>1)+2 && board[rf-1][ff] == EmptySquare && // [HGM] grand
801 gameInfo.variant != VariantShatranj && /* [HGM] */
802 gameInfo.variant != VariantCourier && /* [HGM] */
803 board[rf-2][ff] == EmptySquare) {
804 callback(board, flags, NormalMove,
805 rf, ff, rf-2, ff, closure);
807 for (s = -1; s <= 1; s += 2) {
808 if (rf > 0 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
809 ((flags & F_KRIEGSPIEL_CAPTURE) ||
810 WhitePiece(board[rf - 1][ff + s]))) {
811 callback(board, flags,
812 rf <= promoRank ? BlackPromotion : NormalMove,
813 rf, ff, rf - 1, ff + s, closure);
815 if (rf < BOARD_HEIGHT>>1) {
816 if (ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
817 (epfile == ff + s || epfile == EP_UNKNOWN) && rf > 2 &&
818 board[rf][ff + s] == WhitePawn &&
819 board[rf-1][ff + s] == EmptySquare) {
820 callback(board, flags, BlackCapturesEnPassant,
821 rf, ff, rf-1, ff + s, closure);
831 for (i = -1; i <= 1; i += 2)
832 for (j = -1; j <= 1; j += 2)
833 for (s = 1; s <= 2; s++) {
836 if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
837 && ( gameInfo.variant != VariantXiangqi || board[rf+i*(s-1)][ff+j*(2-s)] == EmptySquare)
838 && !SameColor(board[rf][ff], board[rt][ft]))
839 callback(board, flags, NormalMove,
840 rf, ff, rt, ft, closure);
844 case SHOGI WhiteKnight:
845 for (s = -1; s <= 1; s += 2) {
846 if (rf < BOARD_HEIGHT-2 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
847 !SameColor(board[rf][ff], board[rf + 2][ff + s])) {
848 callback(board, flags, NormalMove,
849 rf, ff, rf + 2, ff + s, closure);
854 case SHOGI BlackKnight:
855 for (s = -1; s <= 1; s += 2) {
856 if (rf > 1 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
857 !SameColor(board[rf][ff], board[rf - 2][ff + s])) {
858 callback(board, flags, NormalMove,
859 rf, ff, rf - 2, ff + s, closure);
866 for (d = 0; d <= 1; d++)
867 for (s = -1; s <= 1; s += 2) {
870 rt = rf + (i * s) * d;
871 ft = ff + (i * s) * (1 - d);
872 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
873 if (m == 0 && board[rt][ft] == EmptySquare)
874 callback(board, flags, NormalMove,
875 rf, ff, rt, ft, closure);
876 if (m == 1 && board[rt][ft] != EmptySquare &&
877 !SameColor(board[rf][ff], board[rt][ft]) )
878 callback(board, flags, NormalMove,
879 rf, ff, rt, ft, closure);
880 if (board[rt][ft] != EmptySquare && m++) break;
885 /* Gold General (and all its promoted versions) . First do the */
886 /* diagonal forward steps, then proceed as normal Wazir */
887 case SHOGI (PROMOTED WhitePawn):
888 if(gameInfo.variant == VariantShogi) goto WhiteGold;
889 case SHOGI (PROMOTED BlackPawn):
890 if(gameInfo.variant == VariantShogi) goto BlackGold;
891 SlideVertical(board, flags, rf, ff, callback, closure);
894 case SHOGI (PROMOTED WhiteKnight):
895 if(gameInfo.variant == VariantShogi) goto WhiteGold;
896 case SHOGI BlackDrunk:
897 case SHOGI BlackAlfil:
898 Ferz(board, flags, rf, ff, callback, closure);
899 StepSideways(board, flags, rf, ff, callback, closure);
900 StepBackward(board, flags, rf, ff, callback, closure);
903 case SHOGI (PROMOTED BlackKnight):
904 if(gameInfo.variant == VariantShogi) goto BlackGold;
905 case SHOGI WhiteDrunk:
906 case SHOGI WhiteAlfil:
907 Ferz(board, flags, rf, ff, callback, closure);
908 StepSideways(board, flags, rf, ff, callback, closure);
909 StepForward(board, flags, rf, ff, callback, closure);
913 case SHOGI WhiteStag:
914 case SHOGI BlackStag:
915 if(gameInfo.variant == VariantShogi) goto BlackGold;
916 SlideVertical(board, flags, rf, ff, callback, closure);
917 Ferz(board, flags, rf, ff, callback, closure);
918 StepSideways(board, flags, rf, ff, callback, closure);
921 case SHOGI (PROMOTED WhiteQueen):
922 case SHOGI WhiteTokin:
923 case SHOGI WhiteWazir:
925 StepDiagForward(board, flags, rf, ff, callback, closure);
926 Wazir(board, flags, rf, ff, callback, closure);
929 case SHOGI (PROMOTED BlackQueen):
930 case SHOGI BlackTokin:
931 case SHOGI BlackWazir:
933 StepDiagBackward(board, flags, rf, ff, callback, closure);
934 Wazir(board, flags, rf, ff, callback, closure);
939 Wazir(board, flags, rf, ff, callback, closure);
942 case SHOGI WhiteMarshall:
943 case SHOGI BlackMarshall:
944 Ferz(board, flags, rf, ff, callback, closure);
945 for (d = 0; d <= 1; d++)
946 for (s = -2; s <= 2; s += 4) {
948 ft = ff + s * (1 - d);
949 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) continue;
950 if (!SameColor(board[rf][ff], board[rt][ft]) )
951 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
955 case SHOGI WhiteAngel:
956 case SHOGI BlackAngel:
957 Wazir(board, flags, rf, ff, callback, closure);
961 /* [HGM] support Shatranj pieces */
962 for (rs = -1; rs <= 1; rs += 2)
963 for (fs = -1; fs <= 1; fs += 2) {
966 if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
967 && ( gameInfo.variant != VariantXiangqi ||
968 board[rf+rs][ff+fs] == EmptySquare && (2*rf < BOARD_HEIGHT) == (2*rt < BOARD_HEIGHT) )
970 && !SameColor(board[rf][ff], board[rt][ft]))
971 callback(board, flags, NormalMove,
972 rf, ff, rt, ft, closure);
973 if(gameInfo.variant == VariantShatranj || gameInfo.variant == VariantCourier ||
974 gameInfo.variant == VariantChu || gameInfo.variant == VariantXiangqi) continue; // classical Alfil
975 rt = rf + rs; // in unknown variant we assume Modern Elephant, which can also do one step
977 if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
978 && !SameColor(board[rf][ff], board[rt][ft]))
979 callback(board, flags, NormalMove,
980 rf, ff, rt, ft, closure);
982 if(gameInfo.variant == VariantSpartan)
983 for(fs = -1; fs <= 1; fs += 2) {
985 if (!(ft < BOARD_LEFT || ft >= BOARD_RGHT) && board[rf][ft] == EmptySquare)
986 callback(board, flags, NormalMove, rf, ff, rf, ft, closure);
990 /* Make Dragon-Horse also do Dababba moves outside Shogi, for better disambiguation in variant Fairy */
993 if(gameInfo.variant == VariantChuChess) goto DragonHorse;
994 for (d = 0; d <= 1; d++) // Dababba moves that Rook cannot do
995 for (s = -2; s <= 2; s += 4) {
997 ft = ff + s * (1 - d);
998 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) continue;
999 if (SameColor(board[rf][ff], board[rt][ft])) continue;
1000 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
1003 /* Shogi Dragon Horse has to continue with Wazir after Bishop */
1004 case SHOGI WhiteCardinal:
1005 case SHOGI BlackCardinal:
1006 case SHOGI WhitePCardinal:
1007 case SHOGI BlackPCardinal:
1009 Bishop(board, flags, rf, ff, callback, closure);
1010 Wazir(board, flags, rf, ff, callback, closure);
1013 /* Capablanca Archbishop continues as Knight */
1016 Knight(board, flags, rf, ff, callback, closure);
1018 /* Shogi Bishops are ordinary Bishops */
1019 case SHOGI WhiteBishop:
1020 case SHOGI BlackBishop:
1021 case SHOGI WhitePBishop:
1022 case SHOGI BlackPBishop:
1025 Bishop(board, flags, rf, ff, callback, closure);
1028 /* Shogi Lance is unlike anything, and asymmetric at that */
1029 case SHOGI WhiteQueen:
1030 if(gameInfo.variant == VariantChu) goto doQueen;
1034 if (rt >= BOARD_HEIGHT) break;
1035 if (SameColor(board[rf][ff], board[rt][ft])) break;
1036 callback(board, flags, NormalMove,
1037 rf, ff, rt, ft, closure);
1038 if (board[rt][ft] != EmptySquare) break;
1042 case SHOGI BlackQueen:
1043 if(gameInfo.variant == VariantChu) goto doQueen;
1048 if (SameColor(board[rf][ff], board[rt][ft])) break;
1049 callback(board, flags, NormalMove,
1050 rf, ff, rt, ft, closure);
1051 if (board[rt][ft] != EmptySquare) break;
1055 /* Make Dragon-King Dababba & Rook-like outside Shogi, for better disambiguation in variant Fairy */
1058 if(gameInfo.variant == VariantChuChess) goto DragonKing;
1059 for (d = 0; d <= 1; d++) // Dababba moves that Rook cannot do
1060 for (s = -2; s <= 2; s += 4) {
1062 ft = ff + s * (1 - d);
1063 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) continue;
1064 if (board[rf+rt>>1][ff+ft>>1] == EmptySquare && gameInfo.variant != VariantSpartan) continue;
1065 if (SameColor(board[rf][ff], board[rt][ft])) continue;
1066 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
1068 if(gameInfo.variant == VariantSpartan) // in Spartan Chess restrict range to modern Dababba
1069 Wazir(board, flags, rf, ff, callback, closure);
1071 Rook(board, flags, rf, ff, callback, closure);
1074 /* Shogi Dragon King has to continue as Ferz after Rook moves */
1075 case SHOGI WhiteDragon:
1076 case SHOGI BlackDragon:
1077 case SHOGI WhitePDragon:
1078 case SHOGI BlackPDragon:
1080 Rook(board, flags, rf, ff, callback, closure);
1081 Ferz(board, flags, rf, ff, callback, closure);
1085 /* Capablanca Chancellor sets flag to continue as Knight */
1088 Rook(board, flags, rf, ff, callback, closure);
1089 if(gameInfo.variant == VariantSpartan) // in Spartan Chess Chancellor is used for Dragon King.
1090 Ferz(board, flags, rf, ff, callback, closure);
1092 Knight(board, flags, rf, ff, callback, closure);
1095 /* Shogi Rooks are ordinary Rooks */
1096 case SHOGI WhiteRook:
1097 case SHOGI BlackRook:
1098 case SHOGI WhitePRook:
1099 case SHOGI BlackPRook:
1102 Rook(board, flags, rf, ff, callback, closure);
1107 case SHOGI WhiteMother:
1108 case SHOGI BlackMother:
1110 Rook(board, flags, rf, ff, callback, closure);
1111 Bishop(board, flags, rf, ff, callback, closure);
1114 case SHOGI WhitePawn:
1115 StepForward(board, flags, rf, ff, callback, closure);
1118 case SHOGI BlackPawn:
1119 StepBackward(board, flags, rf, ff, callback, closure);
1123 if(gameInfo.variant != VariantMakruk && gameInfo.variant != VariantASEAN) goto commoner;
1124 case SHOGI WhiteFerz:
1125 Ferz(board, flags, rf, ff, callback, closure);
1126 StepForward(board, flags, rf, ff, callback, closure);
1130 if(gameInfo.variant != VariantMakruk && gameInfo.variant != VariantASEAN) goto commoner;
1131 case SHOGI BlackFerz:
1132 StepBackward(board, flags, rf, ff, callback, closure);
1136 /* [HGM] support Shatranj pieces */
1137 Ferz(board, flags, rf, ff, callback, closure);
1142 Knight(board, flags, rf, ff, callback, closure); // [HGM] superchess: use for Centaur
1145 case SHOGI WhiteMonarch:
1146 case SHOGI BlackMonarch:
1147 case SHOGI WhiteKing:
1148 case SHOGI BlackKing:
1151 Ferz(board, flags, rf, ff, callback, closure);
1152 Wazir(board, flags, rf, ff, callback, closure);
1155 case WhiteNightrider:
1156 case BlackNightrider:
1157 for (i = -1; i <= 1; i += 2)
1158 for (j = -1; j <= 1; j += 2)
1159 for (s = 1; s <= 2; s++) { int k;
1162 ft = ff + k*j*(3-s);
1163 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
1164 if (SameColor(board[rf][ff], board[rt][ft])) break;
1165 callback(board, flags, NormalMove,
1166 rf, ff, rt, ft, closure);
1167 if (board[rt][ft] != EmptySquare) break;
1173 Bishop(board, flags, rf, ff, callback, closure);
1174 Rook(board, flags, rf, ff, callback, closure);
1175 Knight(board, flags, rf, ff, callback, closure);
1178 // Use Lance as Berolina / Spartan Pawn.
1180 if(gameInfo.variant == VariantSuper) goto Amazon;
1181 if (rf < BOARD_HEIGHT-1 && BlackPiece(board[rf + 1][ff]))
1182 callback(board, flags,
1183 rf >= BOARD_HEIGHT-1-promoRank ? WhitePromotion : NormalMove,
1184 rf, ff, rf + 1, ff, closure);
1185 for (s = -1; s <= 1; s += 2) {
1186 if (rf < BOARD_HEIGHT-1 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT && board[rf + 1][ff + s] == EmptySquare)
1187 callback(board, flags,
1188 rf >= BOARD_HEIGHT-1-promoRank ? WhitePromotion : NormalMove,
1189 rf, ff, rf + 1, ff + s, closure);
1190 if (rf == 1 && ff + 2*s >= BOARD_LEFT && ff + 2*s < BOARD_RGHT && board[3][ff + 2*s] == EmptySquare )
1191 callback(board, flags, NormalMove, rf, ff, 3, ff + 2*s, closure);
1196 if(gameInfo.variant == VariantSuper) goto Amazon;
1197 if (rf > 0 && WhitePiece(board[rf - 1][ff]))
1198 callback(board, flags,
1199 rf <= promoRank ? BlackPromotion : NormalMove,
1200 rf, ff, rf - 1, ff, closure);
1201 for (s = -1; s <= 1; s += 2) {
1202 if (rf > 0 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT && board[rf - 1][ff + s] == EmptySquare)
1203 callback(board, flags,
1204 rf <= promoRank ? BlackPromotion : NormalMove,
1205 rf, ff, rf - 1, ff + s, closure);
1206 if (rf == BOARD_HEIGHT-2 && ff + 2*s >= BOARD_LEFT && ff + 2*s < BOARD_RGHT && board[rf-2][ff + 2*s] == EmptySquare )
1207 callback(board, flags, NormalMove, rf, ff, rf-2, ff + 2*s, closure);
1211 case SHOGI WhiteNothing:
1212 case SHOGI BlackNothing:
1213 case SHOGI WhiteLion:
1214 case SHOGI BlackLion:
1217 for(rt = rf - 2; rt <= rf + 2; rt++) for(ft = ff - 2; ft <= ff + 2; ft++) {
1218 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) continue;
1219 if (!(ff == ft && rf == rt) && SameColor(board[rf][ff], board[rt][ft])) continue;
1220 i = (killX >= 0 && (rt-killY)*(rt-killY) + (killX-ft)*(killX-ft) < 3); legNr += 2*i;
1221 callback(board, flags, (rt-rf)*(rt-rf) + (ff-ft)*(ff-ft) < 3 && board[rt][ft] != EmptySquare ? FirstLeg : NormalMove,
1222 rf, ff, rt, ft, closure);
1227 case SHOGI WhiteFalcon:
1228 case SHOGI BlackFalcon:
1229 case SHOGI WhitePDagger:
1230 case SHOGI BlackPDagger:
1231 SlideSideways(board, flags, rf, ff, callback, closure);
1232 StepVertical(board, flags, rf, ff, callback, closure);
1235 case SHOGI WhiteCobra:
1236 case SHOGI BlackCobra:
1237 StepVertical(board, flags, rf, ff, callback, closure);
1240 case SHOGI (PROMOTED WhiteFerz):
1241 if(gameInfo.variant == VariantShogi) goto WhiteGold;
1242 case SHOGI (PROMOTED BlackFerz):
1243 if(gameInfo.variant == VariantShogi) goto BlackGold;
1244 case SHOGI WhitePSword:
1245 case SHOGI BlackPSword:
1246 SlideVertical(board, flags, rf, ff, callback, closure);
1247 StepSideways(board, flags, rf, ff, callback, closure);
1250 case SHOGI WhiteUnicorn:
1251 case SHOGI BlackUnicorn:
1252 Ferz(board, flags, rf, ff, callback, closure);
1253 StepVertical(board, flags, rf, ff, callback, closure);
1256 case SHOGI WhiteMan:
1257 StepDiagForward(board, flags, rf, ff, callback, closure);
1258 StepVertical(board, flags, rf, ff, callback, closure);
1261 case SHOGI BlackMan:
1262 StepDiagBackward(board, flags, rf, ff, callback, closure);
1263 StepVertical(board, flags, rf, ff, callback, closure);
1266 case SHOGI WhiteHCrown:
1267 case SHOGI BlackHCrown:
1268 Bishop(board, flags, rf, ff, callback, closure);
1269 SlideSideways(board, flags, rf, ff, callback, closure);
1272 case SHOGI WhiteCrown:
1273 case SHOGI BlackCrown:
1274 Bishop(board, flags, rf, ff, callback, closure);
1275 SlideVertical(board, flags, rf, ff, callback, closure);
1278 case SHOGI WhiteHorned:
1279 Sting(board, flags, rf, ff, 1, 0, callback, closure);
1280 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1281 if(killX >= 0) break;
1282 Bishop(board, flags, rf, ff, callback, closure);
1283 SlideSideways(board, flags, rf, ff, callback, closure);
1284 SlideBackward(board, flags, rf, ff, callback, closure);
1287 case SHOGI BlackHorned:
1288 Sting(board, flags, rf, ff, -1, 0, callback, closure);
1289 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1290 if(killX >= 0) break;
1291 Bishop(board, flags, rf, ff, callback, closure);
1292 SlideSideways(board, flags, rf, ff, callback, closure);
1293 SlideForward(board, flags, rf, ff, callback, closure);
1296 case SHOGI WhiteEagle:
1297 Sting(board, flags, rf, ff, 1, 1, callback, closure);
1298 Sting(board, flags, rf, ff, 1, -1, callback, closure);
1299 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1300 if(killX >= 0) break;
1301 Rook(board, flags, rf, ff, callback, closure);
1302 SlideDiagBackward(board, flags, rf, ff, callback, closure);
1305 case SHOGI BlackEagle:
1306 Sting(board, flags, rf, ff, -1, 1, callback, closure);
1307 Sting(board, flags, rf, ff, -1, -1, callback, closure);
1308 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1309 if(killX >= 0) break;
1310 Rook(board, flags, rf, ff, callback, closure);
1311 SlideDiagForward(board, flags, rf, ff, callback, closure);
1314 case SHOGI WhiteDolphin:
1315 case SHOGI BlackHorse:
1316 SlideDiagBackward(board, flags, rf, ff, callback, closure);
1317 SlideVertical(board, flags, rf, ff, callback, closure);
1320 case SHOGI BlackDolphin:
1321 case SHOGI WhiteHorse:
1322 SlideDiagForward(board, flags, rf, ff, callback, closure);
1323 SlideVertical(board, flags, rf, ff, callback, closure);
1326 case SHOGI WhiteLance:
1327 SlideForward(board, flags, rf, ff, callback, closure);
1330 case SHOGI BlackLance:
1331 SlideBackward(board, flags, rf, ff, callback, closure);
1334 case WhiteFalcon: // [HGM] wild: for wildcards, self-capture symbolizes move to anywhere
1338 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1351 int rFilter, fFilter; // [HGM] speed: sorry, but I get a bit tired of this closure madness
1352 Board xqCheckers, nullBoard;
1354 extern void GenLegalCallback P((Board board, int flags, ChessMove kind,
1355 int rf, int ff, int rt, int ft,
1359 GenLegalCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1361 register GenLegalClosure *cl = (GenLegalClosure *) closure;
1363 if(rFilter >= 0 && rFilter != rt || fFilter >= 0 && fFilter != ft) return; // [HGM] speed: ignore moves with wrong to-square
1365 if (board[EP_STATUS] == EP_IRON_LION && (board[rt][ft] == WhiteLion || board[rt][ft] == BlackLion)) return; //[HGM] lion
1367 if (!(flags & F_IGNORE_CHECK) ) {
1368 int check, promo = (gameInfo.variant == VariantSpartan && kind == BlackPromotion);
1371 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++)
1372 kings += (board[r][f] == BlackKing);
1376 board[rf][ff] = BlackKing; // [HGM] spartan: promote to King before check-test
1378 check = CheckTest(board, flags, rf, ff, rt, ft,
1379 kind == WhiteCapturesEnPassant ||
1380 kind == BlackCapturesEnPassant);
1381 if(promo) board[rf][ff] = BlackLance;
1384 if (flags & F_ATOMIC_CAPTURE) {
1385 if (board[rt][ft] != EmptySquare ||
1386 kind == WhiteCapturesEnPassant || kind == BlackCapturesEnPassant) {
1388 ChessSquare king = (flags & F_WHITE_ON_MOVE) ? WhiteKing : BlackKing;
1389 if (board[rf][ff] == king) return;
1390 for (r = rt-1; r <= rt+1; r++) {
1391 for (f = ft-1; f <= ft+1; f++) {
1392 if (r >= 0 && r < BOARD_HEIGHT && f >= BOARD_LEFT && f < BOARD_RGHT &&
1393 board[r][f] == king) return;
1398 cl->cb(board, flags, kind, rf, ff, rt, ft, cl->cl);
1405 int captures; // [HGM] losers
1406 } LegalityTestClosure;
1409 /* Like GenPseudoLegal, but (1) include castling moves, (2) unless
1410 F_IGNORE_CHECK is set in the flags, omit moves that would leave the
1411 king in check, and (3) if F_ATOMIC_CAPTURE is set in the flags, omit
1412 moves that would destroy your own king. The CASTLE_OK flags are
1413 true if castling is not yet ruled out by a move of the king or
1414 rook. Return TRUE if the player on move is currently in check and
1415 F_IGNORE_CHECK is not set. [HGM] add castlingRights parameter */
1417 GenLegal (Board board, int flags, MoveCallback callback, VOIDSTAR closure, ChessSquare filter)
1420 int ff, ft, k, left, right, swap;
1421 int ignoreCheck = (flags & F_IGNORE_CHECK) != 0;
1422 ChessSquare wKing = WhiteKing, bKing = BlackKing, *castlingRights = board[CASTLING];
1423 int inCheck = !ignoreCheck && CheckTest(board, flags, -1, -1, -1, -1, FALSE); // kludge alert: this would mark pre-existing checkers if status==1
1428 xqCheckers[EP_STATUS] *= 2; // quasi: if previous CheckTest has been marking, we now set flag for suspending same checkers
1429 if(filter == EmptySquare) rFilter = fFilter = -1; // [HGM] speed: do not filter on square if we do not filter on piece
1430 GenPseudoLegal(board, flags, GenLegalCallback, (VOIDSTAR) &cl, filter);
1432 if (inCheck) return TRUE;
1434 /* Generate castling moves */
1435 if(gameInfo.variant == VariantKnightmate) { /* [HGM] Knightmate */
1436 wKing = WhiteUnicorn; bKing = BlackUnicorn;
1439 p = (flags & F_WHITE_ON_MOVE ? pieceDesc[wKing] : pieceDesc[bKing]);
1440 if(p && strchr(p, 'O')) return FALSE; // [HGM] gen: castlings were already generated from string
1442 for (ff = BOARD_WIDTH>>1; ff >= (BOARD_WIDTH-1)>>1; ff-- /*ics wild 1*/) {
1443 if ((flags & F_WHITE_ON_MOVE) &&
1444 (flags & F_WHITE_KCASTLE_OK) &&
1445 board[0][ff] == wKing &&
1446 board[0][ff + 1] == EmptySquare &&
1447 board[0][ff + 2] == EmptySquare &&
1448 board[0][BOARD_RGHT-3] == EmptySquare &&
1449 board[0][BOARD_RGHT-2] == EmptySquare &&
1450 board[0][BOARD_RGHT-1] == WhiteRook &&
1451 castlingRights[0] != NoRights && /* [HGM] check rights */
1452 ( castlingRights[2] == ff || castlingRights[6] == ff ) &&
1454 (!CheckTest(board, flags, 0, ff, 0, ff + 1, FALSE) &&
1455 !CheckTest(board, flags, 0, ff, 0, BOARD_RGHT-3, FALSE) &&
1456 (gameInfo.variant != VariantJanus || !CheckTest(board, flags, 0, ff, 0, BOARD_RGHT-2, FALSE)) &&
1457 !CheckTest(board, flags, 0, ff, 0, ff + 2, FALSE)))) {
1459 callback(board, flags,
1460 ff==BOARD_WIDTH>>1 ? WhiteKingSideCastle : WhiteKingSideCastleWild,
1461 0, ff, 0, ff + ((gameInfo.boardWidth+2)>>2) + (gameInfo.variant == VariantJanus), closure);
1463 if ((flags & F_WHITE_ON_MOVE) &&
1464 (flags & F_WHITE_QCASTLE_OK) &&
1465 board[0][ff] == wKing &&
1466 board[0][ff - 1] == EmptySquare &&
1467 board[0][ff - 2] == EmptySquare &&
1468 board[0][BOARD_LEFT+2] == EmptySquare &&
1469 board[0][BOARD_LEFT+1] == EmptySquare &&
1470 board[0][BOARD_LEFT+0] == WhiteRook &&
1471 castlingRights[1] != NoRights && /* [HGM] check rights */
1472 ( castlingRights[2] == ff || castlingRights[6] == ff ) &&
1474 (!CheckTest(board, flags, 0, ff, 0, ff - 1, FALSE) &&
1475 !CheckTest(board, flags, 0, ff, 0, BOARD_LEFT+3, FALSE) &&
1476 !CheckTest(board, flags, 0, ff, 0, ff - 2, FALSE)))) {
1478 callback(board, flags,
1479 ff==BOARD_WIDTH>>1 ? WhiteQueenSideCastle : WhiteQueenSideCastleWild,
1480 0, ff, 0, ff - ((gameInfo.boardWidth+2)>>2), closure);
1482 if (!(flags & F_WHITE_ON_MOVE) &&
1483 (flags & F_BLACK_KCASTLE_OK) &&
1484 board[BOARD_HEIGHT-1][ff] == bKing &&
1485 board[BOARD_HEIGHT-1][ff + 1] == EmptySquare &&
1486 board[BOARD_HEIGHT-1][ff + 2] == EmptySquare &&
1487 board[BOARD_HEIGHT-1][BOARD_RGHT-3] == EmptySquare &&
1488 board[BOARD_HEIGHT-1][BOARD_RGHT-2] == EmptySquare &&
1489 board[BOARD_HEIGHT-1][BOARD_RGHT-1] == BlackRook &&
1490 castlingRights[3] != NoRights && /* [HGM] check rights */
1491 ( castlingRights[5] == ff || castlingRights[7] == ff ) &&
1493 (!CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff + 1, FALSE) &&
1494 !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, BOARD_RGHT-3, FALSE) &&
1495 (gameInfo.variant != VariantJanus || !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, BOARD_RGHT-2, FALSE)) &&
1496 !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff + 2, FALSE)))) {
1498 callback(board, flags,
1499 ff==BOARD_WIDTH>>1 ? BlackKingSideCastle : BlackKingSideCastleWild,
1500 BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff + ((gameInfo.boardWidth+2)>>2) + (gameInfo.variant == VariantJanus), closure);
1502 if (!(flags & F_WHITE_ON_MOVE) &&
1503 (flags & F_BLACK_QCASTLE_OK) &&
1504 board[BOARD_HEIGHT-1][ff] == bKing &&
1505 board[BOARD_HEIGHT-1][ff - 1] == EmptySquare &&
1506 board[BOARD_HEIGHT-1][ff - 2] == EmptySquare &&
1507 board[BOARD_HEIGHT-1][BOARD_LEFT+2] == EmptySquare &&
1508 board[BOARD_HEIGHT-1][BOARD_LEFT+1] == EmptySquare &&
1509 board[BOARD_HEIGHT-1][BOARD_LEFT+0] == BlackRook &&
1510 castlingRights[4] != NoRights && /* [HGM] check rights */
1511 ( castlingRights[5] == ff || castlingRights[7] == ff ) &&
1513 (!CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff - 1, FALSE) &&
1514 !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, BOARD_LEFT+3, FALSE) &&
1515 !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff - 2, FALSE)))) {
1517 callback(board, flags,
1518 ff==BOARD_WIDTH>>1 ? BlackQueenSideCastle : BlackQueenSideCastleWild,
1519 BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff - ((gameInfo.boardWidth+2)>>2), closure);
1523 if((swap = gameInfo.variant == VariantSChess) || flags & F_FRC_TYPE_CASTLING) {
1525 /* generate all potential FRC castling moves (KxR), ignoring flags */
1526 /* [HGM] test if the Rooks we find have castling rights */
1527 /* In S-Chess we generate RxK for allowed castlings, for gating at Rook square */
1530 if ((flags & F_WHITE_ON_MOVE) != 0) {
1531 ff = castlingRights[2]; /* King file if we have any rights */
1532 if(ff != NoRights && board[0][ff] == WhiteKing) {
1533 if (appData.debugMode) {
1534 fprintf(debugFP, "FRC castling, %d %d %d %d %d %d\n",
1535 castlingRights[0],castlingRights[1],ff,castlingRights[3],castlingRights[4],castlingRights[5]);
1537 ft = castlingRights[0]; /* Rook file if we have H-side rights */
1539 right = BOARD_RGHT-2;
1540 if(ff == BOARD_RGHT-2) left = right = ff-1; /* special case */
1541 for(k=left; k<=right && ft != NoRights; k++) /* first test if blocked */
1542 if(k != ft && board[0][k] != EmptySquare) ft = NoRights;
1543 for(k=left; k<right && ft != NoRights; k++) /* then if not checked */
1544 if(!ignoreCheck && CheckTest(board, flags, 0, ff, 0, k, FALSE)) ft = NoRights;
1545 if(ft != NoRights && board[0][ft] == WhiteRook) {
1546 if(flags & F_FRC_TYPE_CASTLING) callback(board, flags, WhiteHSideCastleFR, 0, ff, 0, ft, closure);
1547 if(swap) callback(board, flags, WhiteHSideCastleFR, 0, ft, 0, ff, closure);
1550 ft = castlingRights[1]; /* Rook file if we have A-side rights */
1551 left = BOARD_LEFT+2;
1553 if(ff <= BOARD_LEFT+2) { left = ff+1; right = BOARD_LEFT+3; }
1554 for(k=left; k<=right && ft != NoRights; k++) /* first test if blocked */
1555 if(k != ft && board[0][k] != EmptySquare) ft = NoRights;
1556 if(ft == 0 && ff != 1 && board[0][1] != EmptySquare) ft = NoRights; /* Rook can be blocked on b1 */
1557 if(ff > BOARD_LEFT+2)
1558 for(k=left+1; k<=right && ft != NoRights; k++) /* then if not checked */
1559 if(!ignoreCheck && CheckTest(board, flags, 0, ff, 0, k, FALSE)) ft = NoRights;
1560 if(ft != NoRights && board[0][ft] == WhiteRook) {
1561 if(flags & F_FRC_TYPE_CASTLING) callback(board, flags, WhiteASideCastleFR, 0, ff, 0, ft, closure);
1562 if(swap) callback(board, flags, WhiteASideCastleFR, 0, ft, 0, ff, closure);
1566 ff = castlingRights[5]; /* King file if we have any rights */
1567 if(ff != NoRights && board[BOARD_HEIGHT-1][ff] == BlackKing) {
1568 ft = castlingRights[3]; /* Rook file if we have H-side rights */
1570 right = BOARD_RGHT-2;
1571 if(ff == BOARD_RGHT-2) left = right = ff-1; /* special case */
1572 for(k=left; k<=right && ft != NoRights; k++) /* first test if blocked */
1573 if(k != ft && board[BOARD_HEIGHT-1][k] != EmptySquare) ft = NoRights;
1574 for(k=left; k<right && ft != NoRights; k++) /* then if not checked */
1575 if(!ignoreCheck && CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, k, FALSE)) ft = NoRights;
1576 if(ft != NoRights && board[BOARD_HEIGHT-1][ft] == BlackRook) {
1577 if(flags & F_FRC_TYPE_CASTLING) callback(board, flags, BlackHSideCastleFR, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ft, closure);
1578 if(swap) callback(board, flags, BlackHSideCastleFR, BOARD_HEIGHT-1, ft, BOARD_HEIGHT-1, ff, closure);
1581 ft = castlingRights[4]; /* Rook file if we have A-side rights */
1582 left = BOARD_LEFT+2;
1584 if(ff <= BOARD_LEFT+2) { left = ff+1; right = BOARD_LEFT+3; }
1585 for(k=left; k<=right && ft != NoRights; k++) /* first test if blocked */
1586 if(k != ft && board[BOARD_HEIGHT-1][k] != EmptySquare) ft = NoRights;
1587 if(ft == 0 && ff != 1 && board[BOARD_HEIGHT-1][1] != EmptySquare) ft = NoRights; /* Rook can be blocked on b8 */
1588 if(ff > BOARD_LEFT+2)
1589 for(k=left+1; k<=right && ft != NoRights; k++) /* then if not checked */
1590 if(!ignoreCheck && CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, k, FALSE)) ft = NoRights;
1591 if(ft != NoRights && board[BOARD_HEIGHT-1][ft] == BlackRook) {
1592 if(flags & F_FRC_TYPE_CASTLING) callback(board, flags, BlackASideCastleFR, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ft, closure);
1593 if(swap) callback(board, flags, BlackASideCastleFR, BOARD_HEIGHT-1, ft, BOARD_HEIGHT-1, ff, closure);
1610 extern void CheckTestCallback P((Board board, int flags, ChessMove kind,
1611 int rf, int ff, int rt, int ft,
1616 CheckTestCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1618 register CheckTestClosure *cl = (CheckTestClosure *) closure;
1620 if (rt == cl->rking && ft == cl->fking) {
1621 if(xqCheckers[EP_STATUS] >= 2 && xqCheckers[rf][ff]) return; // checker is piece with suspended checking power
1623 xqCheckers[rf][ff] = xqCheckers[EP_STATUS] & 1; // remember who is checking (if status == 1)
1625 if( board[EP_STATUS] == EP_ROYAL_LION && (board[rt][ft] == WhiteLion || board[rt][ft] == BlackLion)
1626 && (gameInfo.variant != VariantLion || board[rf][ff] != WhiteKing && board[rf][ff] != BlackKing) )
1627 cl->check++; // [HGM] lion: forbidden counterstrike against Lion equated to putting yourself in check
1631 /* If the player on move were to move from (rf, ff) to (rt, ft), would
1632 he leave himself in check? Or if rf == -1, is the player on move
1633 in check now? enPassant must be TRUE if the indicated move is an
1634 e.p. capture. The possibility of castling out of a check along the
1635 back rank is not accounted for (i.e., we still return nonzero), as
1636 this is illegal anyway. Return value is the number of times the
1637 king is in check. */
1639 CheckTest (Board board, int flags, int rf, int ff, int rt, int ft, int enPassant)
1641 CheckTestClosure cl;
1642 ChessSquare king = flags & F_WHITE_ON_MOVE ? WhiteKing : BlackKing;
1643 ChessSquare captured = EmptySquare, ep=0, trampled=0;
1644 int saveKill = killX;
1645 /* Suppress warnings on uninitialized variables */
1647 if(gameInfo.variant == VariantXiangqi)
1648 king = flags & F_WHITE_ON_MOVE ? WhiteWazir : BlackWazir;
1649 if(gameInfo.variant == VariantKnightmate)
1650 king = flags & F_WHITE_ON_MOVE ? WhiteUnicorn : BlackUnicorn;
1651 if(gameInfo.variant == VariantChu || gameInfo.variant == VariantShogi) { // strictly speaking this is not needed, as Chu officially has no check
1652 int r, f, k = king, royals=0, prince = flags & F_WHITE_ON_MOVE ? WhiteMonarch : BlackMonarch;
1653 if(gameInfo.variant == VariantShogi) prince -= 11; // White/BlackFalcon
1654 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++) {
1655 if(board[r][f] == k || board[r][f] == prince) {
1656 if(++royals > 1) return FALSE; // no check if we have two royals (ignores double captureby Lion!)
1657 king = board[r][f]; // remember hich one we had
1664 captured = board[rf][ft];
1665 board[rf][ft] = EmptySquare;
1667 captured = board[rt][ft];
1668 if(killX >= 0) { trampled = board[killY][killX]; board[killY][killX] = EmptySquare; killX = -1; }
1670 if(rf == DROP_RANK) board[rt][ft] = ff; else { // [HGM] drop
1671 board[rt][ft] = board[rf][ff];
1672 if(rf != rt || ff != ft) board[rf][ff] = EmptySquare;
1674 ep = board[EP_STATUS];
1675 if( captured == WhiteLion || captured == BlackLion ) { // [HGM] lion: Chu Lion-capture rules
1676 ChessSquare victim = killX < 0 ? EmptySquare : trampled;
1677 if( (board[rt][ft] == WhiteLion || board[rt][ft] == BlackLion) && // capturer is Lion
1678 (ff - ft > 1 || ft - ff > 1 || rf - rt > 1 || rt - rf > 1) && // captures from a distance
1679 (victim == EmptySquare || victim == WhitePawn || victim == BlackPawn) ) // no or worthless 'bridge'
1680 board[EP_STATUS] = EP_ROYAL_LION; // on distant Lion x Lion victim must not be pseudo-legally protected
1684 /* For compatibility with ICS wild 9, we scan the board in the
1685 order a1, a2, a3, ... b1, b2, ..., h8 to find the first king,
1686 and we test only whether that one is in check. */
1687 for (cl.fking = BOARD_LEFT+0; cl.fking < BOARD_RGHT; cl.fking++)
1688 for (cl.rking = 0; cl.rking < BOARD_HEIGHT; cl.rking++) {
1689 if (board[cl.rking][cl.fking] == king) {
1691 if(gameInfo.variant == VariantXiangqi) {
1692 /* [HGM] In Xiangqi opposing Kings means check as well */
1694 dir = (king >= BlackPawn) ? -1 : 1;
1695 for( i=cl.rking+dir; i>=0 && i<BOARD_HEIGHT &&
1696 board[i][cl.fking] == EmptySquare; i+=dir );
1697 if(i>=0 && i<BOARD_HEIGHT &&
1698 board[i][cl.fking] == (dir>0 ? BlackWazir : WhiteWazir) )
1701 GenPseudoLegal(board, flags ^ F_WHITE_ON_MOVE, CheckTestCallback, (VOIDSTAR) &cl, EmptySquare);
1702 if(gameInfo.variant != VariantSpartan || cl.check == 0) // in Spartan Chess go on to test if other King is checked too
1703 goto undo_move; /* 2-level break */
1710 if(rf != DROP_RANK) // [HGM] drop
1711 board[rf][ff] = board[rt][ft];
1713 board[rf][ft] = captured;
1714 board[rt][ft] = EmptySquare;
1716 if(saveKill >= 0) board[killY][killX = saveKill] = trampled;
1717 board[rt][ft] = captured;
1719 board[EP_STATUS] = ep;
1722 return cl.fking < BOARD_RGHT ? cl.check : 1000; // [HGM] atomic: return 1000 if we have no king
1726 HasLion (Board board, int flags)
1728 int lion = F_WHITE_ON_MOVE & flags ? WhiteLion : BlackLion;
1730 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++)
1731 if(board[r][f] == lion) return 1;
1736 LegalDrop (Board board, int flags, ChessSquare piece, int rt, int ft)
1737 { // [HGM] put drop legality testing in separate routine for clarity
1739 if(appData.debugMode) fprintf(debugFP, "LegalDrop: %d @ %d,%d)\n", piece, ft, rt);
1740 if(board[rt][ft] != EmptySquare) return ImpossibleMove; // must drop to empty square
1741 n = PieceToNumber(piece);
1742 if((gameInfo.holdingsWidth == 0 || (flags & F_WHITE_ON_MOVE ? board[n][BOARD_WIDTH-1] : board[BOARD_HEIGHT-1-n][0]) != piece)
1743 && gameInfo.variant != VariantBughouse) // in bughouse we don't check for availability, because ICS doesn't always tell us
1744 return ImpossibleMove; // piece not available
1745 if(gameInfo.variant == VariantShogi) { // in Shogi lots of drops are forbidden!
1746 if((piece == WhitePawn || piece == WhiteQueen) && rt == BOARD_HEIGHT-1 ||
1747 (piece == BlackPawn || piece == BlackQueen) && rt == 0 ||
1748 piece == WhiteKnight && rt > BOARD_HEIGHT-3 ||
1749 piece == BlackKnight && rt < 2 ) return IllegalMove; // e.g. where dropped piece has no moves
1750 if(piece == WhitePawn || piece == BlackPawn) {
1751 int r, max = 1 + (BOARD_HEIGHT == 7); // two Pawns per file in Tori!
1752 for(r=1; r<BOARD_HEIGHT-1; r++)
1753 if(!(max -= (board[r][ft] == piece))) return IllegalMove; // or there already is a Pawn in file
1754 // should still test if we mate with this Pawn
1756 } else if(gameInfo.variant == VariantSChess) { // only back-rank drops
1757 if (rt != (piece < BlackPawn ? 0 : BOARD_HEIGHT-1)) return IllegalMove;
1759 if( (piece == WhitePawn || piece == BlackPawn) &&
1760 (rt == 0 || rt == BOARD_HEIGHT -1 ) )
1761 return IllegalMove; /* no pawn drops on 1st/8th */
1763 if(appData.debugMode) fprintf(debugFP, "LegalDrop: %d @ %d,%d)\n", piece, ft, rt);
1764 if (!(flags & F_IGNORE_CHECK) &&
1765 CheckTest(board, flags, DROP_RANK, piece, rt, ft, FALSE) ) return IllegalMove;
1766 return flags & F_WHITE_ON_MOVE ? WhiteDrop : BlackDrop;
1769 extern void LegalityTestCallback P((Board board, int flags, ChessMove kind,
1770 int rf, int ff, int rt, int ft,
1774 LegalityTestCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1776 register LegalityTestClosure *cl = (LegalityTestClosure *) closure;
1778 if(board[rt][ft] != EmptySquare || kind==WhiteCapturesEnPassant || kind==BlackCapturesEnPassant)
1779 cl->captures++; // [HGM] losers: count legal captures
1780 if (rf == cl->rf && ff == cl->ff && rt == cl->rt && ft == cl->ft)
1785 LegalityTest (Board board, int flags, int rf, int ff, int rt, int ft, int promoChar)
1787 LegalityTestClosure cl; ChessSquare piece, filterPiece;
1789 if(quickFlag) flags = flags & ~1 | quickFlag & 1; // [HGM] speed: in quick mode quickFlag specifies side-to-move.
1790 if(rf == DROP_RANK) return LegalDrop(board, flags, ff, rt, ft);
1791 piece = filterPiece = board[rf][ff];
1792 if(PieceToChar(piece) == '~') filterPiece = DEMOTED piece;
1794 /* [HGM] Cobra and Falcon are wildcard pieces; consider all their moves legal */
1795 /* (perhaps we should disallow moves that obviously leave us in check?) */
1796 if((piece == WhiteFalcon || piece == BlackFalcon ||
1797 piece == WhiteCobra || piece == BlackCobra) && gameInfo.variant != VariantChu && !pieceDesc[piece])
1798 return CheckTest(board, flags, rf, ff, rt, ft, FALSE) ? IllegalMove : NormalMove;
1802 cl.rt = rFilter = rt; // [HGM] speed: filter on to-square
1803 cl.ft = fFilter = ft;
1804 cl.kind = IllegalMove;
1805 cl.captures = 0; // [HGM] losers: prepare to count legal captures.
1806 if(flags & F_MANDATORY_CAPTURE) filterPiece = EmptySquare; // [HGM] speed: do not filter in suicide, to find all captures
1807 GenLegal(board, flags, LegalityTestCallback, (VOIDSTAR) &cl, filterPiece);
1808 if((flags & F_MANDATORY_CAPTURE) && cl.captures && board[rt][ft] == EmptySquare
1809 && cl.kind != WhiteCapturesEnPassant && cl.kind != BlackCapturesEnPassant)
1810 return(IllegalMove); // [HGM] losers: if there are legal captures, non-capts are illegal
1812 if(promoChar == 'x') promoChar = NULLCHAR; // [HGM] is this ever the case?
1813 if(gameInfo.variant == VariantSChess && promoChar && promoChar != '=' && board[rf][ff] != WhitePawn && board[rf][ff] != BlackPawn) {
1814 if(board[rf][ff] < BlackPawn) { // white
1815 if(rf != 0) return IllegalMove; // must be on back rank
1816 if(!(board[VIRGIN][ff] & VIRGIN_W)) return IllegalMove; // non-virgin
1817 if(board[PieceToNumber(CharToPiece(ToUpper(promoChar)))][BOARD_WIDTH-2] == 0) return ImpossibleMove;// must be in stock
1818 if(cl.kind == WhiteHSideCastleFR && (ff == BOARD_RGHT-2 || ff == BOARD_RGHT-3)) return ImpossibleMove;
1819 if(cl.kind == WhiteASideCastleFR && (ff == BOARD_LEFT+2 || ff == BOARD_LEFT+3)) return ImpossibleMove;
1821 if(rf != BOARD_HEIGHT-1) return IllegalMove;
1822 if(!(board[VIRGIN][ff] & VIRGIN_B)) return IllegalMove; // non-virgin
1823 if(board[BOARD_HEIGHT-1-PieceToNumber(CharToPiece(ToLower(promoChar)))][1] == 0) return ImpossibleMove;
1824 if(cl.kind == BlackHSideCastleFR && (ff == BOARD_RGHT-2 || ff == BOARD_RGHT-3)) return ImpossibleMove;
1825 if(cl.kind == BlackASideCastleFR && (ff == BOARD_LEFT+2 || ff == BOARD_LEFT+3)) return ImpossibleMove;
1828 if(gameInfo.variant == VariantChu) {
1829 if(cl.kind != NormalMove || promoChar == NULLCHAR || promoChar == '=') return cl.kind;
1830 if(promoChar != '+')
1831 return CharToPiece(promoChar) == EmptySquare ? ImpossibleMove : IllegalMove;
1832 if(PieceToChar(CHUPROMOTED board[rf][ff]) != '+') return ImpossibleMove;
1833 return flags & F_WHITE_ON_MOVE ? WhitePromotion : BlackPromotion;
1835 if(gameInfo.variant == VariantShogi) {
1836 /* [HGM] Shogi promotions. '=' means defer */
1837 if(rf != DROP_RANK && cl.kind == NormalMove) {
1838 ChessSquare piece = board[rf][ff];
1839 int zone = BOARD_HEIGHT/3 + (BOARD_HEIGHT == 8);
1841 if(promoChar == PieceToChar(BlackQueen)) promoChar = NULLCHAR; /* [HGM] Kludge */
1842 if(promoChar == 'd' && (piece == WhiteRook || piece == BlackRook) ||
1843 promoChar == 'h' && (piece == WhiteBishop || piece == BlackBishop) ||
1844 promoChar == 'g' && (piece <= WhiteFerz || piece <= BlackFerz && piece >= BlackPawn) )
1845 promoChar = '+'; // allowed ICS notations
1846 if(appData.debugMode)fprintf(debugFP,"SHOGI promoChar = %c\n", promoChar ? promoChar : '-');
1847 if(promoChar != NULLCHAR && promoChar != '+' && promoChar != '=')
1848 return CharToPiece(promoChar) == EmptySquare ? ImpossibleMove : IllegalMove;
1849 else if(flags & F_WHITE_ON_MOVE) {
1850 if( (int) piece < (int) WhiteWazir &&
1851 (rf >= BOARD_HEIGHT - zone || rt >= BOARD_HEIGHT - zone) ) {
1852 if( (piece == WhitePawn || piece == WhiteQueen) && rt > BOARD_HEIGHT-2 ||
1853 piece == WhiteKnight && rt > BOARD_HEIGHT-3) /* promotion mandatory */
1854 cl.kind = promoChar == '=' ? IllegalMove : WhitePromotion;
1855 else /* promotion optional, default is defer */
1856 cl.kind = promoChar == '+' ? WhitePromotion : WhiteNonPromotion;
1857 } else cl.kind = promoChar == '+' ? IllegalMove : NormalMove;
1859 if( (int) piece < (int) BlackWazir && (rf < zone || rt < zone) ) {
1860 if( (piece == BlackPawn || piece == BlackQueen) && rt < 1 ||
1861 piece == BlackKnight && rt < 2 ) /* promotion obligatory */
1862 cl.kind = promoChar == '=' ? IllegalMove : BlackPromotion;
1863 else /* promotion optional, default is defer */
1864 cl.kind = promoChar == '+' ? BlackPromotion : BlackNonPromotion;
1865 } else cl.kind = promoChar == '+' ? IllegalMove : NormalMove;
1869 if (promoChar != NULLCHAR) {
1870 if(cl.kind == NormalMove && promoChar == '+') { // allow shogi-style promotion is pieceToChar specifies them
1871 ChessSquare piece = board[rf][ff];
1872 if(piece < BlackPawn ? piece > WhiteMan : piece > BlackMan) return ImpossibleMove; // already promoted
1873 // should test if in zone, really
1874 if(gameInfo.variant == VariantChuChess && (piece == WhiteKnight || piece == BlackKnight) && HasLion(board, flags))
1876 if(PieceToChar(PROMOTED piece) == '+') return flags & F_WHITE_ON_MOVE ? WhitePromotion : BlackPromotion;
1878 if(promoChar == '=') cl.kind = IllegalMove; else // [HGM] shogi: no deferred promotion outside Shogi
1879 if (cl.kind == WhitePromotion || cl.kind == BlackPromotion) {
1880 ChessSquare piece = CharToPiece(flags & F_WHITE_ON_MOVE ? ToUpper(promoChar) : ToLower(promoChar));
1881 if(piece == EmptySquare)
1882 cl.kind = ImpossibleMove; // non-existing piece
1883 if(gameInfo.variant == VariantChuChess && promoChar == 'l' && HasLion(board, flags)) {
1884 cl.kind = IllegalMove; // no two Lions
1885 } else if(gameInfo.variant == VariantSpartan && cl.kind == BlackPromotion ) {
1886 if(promoChar != PieceToChar(BlackKing)) {
1887 if(CheckTest(board, flags, rf, ff, rt, ft, FALSE)) cl.kind = IllegalMove; // [HGM] spartan: only promotion to King was possible
1888 if(piece == BlackLance) cl.kind = ImpossibleMove;
1889 } else { // promotion to King allowed only if we do not have two yet
1890 int r, f, kings = 0;
1891 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++) kings += (board[r][f] == BlackKing);
1892 if(kings == 2) cl.kind = IllegalMove;
1894 } else if(piece == WhitePawn && rt == BOARD_HEIGHT-1 ||
1895 piece == BlackPawn && rt == 0) cl.kind = IllegalMove; // cannot stay Pawn on last rank in any variant
1896 else if((piece == WhiteUnicorn || piece == BlackUnicorn) && gameInfo.variant == VariantKnightmate)
1897 cl.kind = IllegalMove; // promotion to Royal Knight not allowed
1898 else if((piece == WhiteKing || piece == BlackKing) && gameInfo.variant != VariantSuicide && gameInfo.variant != VariantGiveaway)
1899 cl.kind = IllegalMove; // promotion to King usually not allowed
1901 cl.kind = IllegalMove;
1911 extern void MateTestCallback P((Board board, int flags, ChessMove kind,
1912 int rf, int ff, int rt, int ft,
1916 MateTestCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1918 register MateTestClosure *cl = (MateTestClosure *) closure;
1923 /* Return MT_NONE, MT_CHECK, MT_CHECKMATE, or MT_STALEMATE */
1925 MateTest (Board board, int flags)
1928 int inCheck, r, f, myPieces=0, hisPieces=0, nrKing=0;
1929 ChessSquare king = flags & F_WHITE_ON_MOVE ? WhiteKing : BlackKing;
1931 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++) {
1932 // [HGM] losers: Count pieces and kings, to detect other unorthodox winning conditions
1933 nrKing += (board[r][f] == king); // stm has king
1934 if( board[r][f] != EmptySquare ) {
1935 if((int)board[r][f] <= (int)king && (int)board[r][f] >= (int)king - (int)WhiteKing + (int)WhitePawn)
1940 switch(gameInfo.variant) { // [HGM] losers: extinction wins
1941 case VariantShatranj:
1942 if(hisPieces == 1) return myPieces > 1 ? MT_BARE : MT_DRAW;
1946 if(nrKing == 0) return MT_NOKING;
1949 if(myPieces == 1) return MT_BARE;
1952 inCheck = GenLegal(board, flags, MateTestCallback, (VOIDSTAR) &cl, EmptySquare);
1953 // [HGM] 3check: yet to do!
1955 return inCheck ? MT_CHECK : MT_NONE;
1957 if(gameInfo.holdingsWidth && gameInfo.variant != VariantSuper && gameInfo.variant != VariantGreat
1958 && gameInfo.variant != VariantSChess && gameInfo.variant != VariantGrand) { // drop game
1959 int r, f, n, holdings = flags & F_WHITE_ON_MOVE ? BOARD_WIDTH-1 : 0;
1960 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++) if(board[r][f] == EmptySquare) // all empty squares
1961 for(n=0; n<BOARD_HEIGHT; n++) // all pieces in hand
1962 if(board[n][holdings] != EmptySquare) {
1963 int moveType = LegalDrop(board, flags, board[n][holdings], r, f);
1964 if(moveType == WhiteDrop || moveType == BlackDrop) return (inCheck ? MT_CHECK : MT_NONE); // we have legal drop
1967 if(gameInfo.variant == VariantSuicide) // [HGM] losers: always stalemate, since no check, but result varies
1968 return myPieces == hisPieces ? MT_STALEMATE :
1969 myPieces > hisPieces ? MT_STAINMATE : MT_STEALMATE;
1970 else if(gameInfo.variant == VariantLosers) return inCheck ? MT_TRICKMATE : MT_STEALMATE;
1971 else if(gameInfo.variant == VariantGiveaway) return MT_STEALMATE; // no check exists, stalemated = win
1973 return inCheck ? MT_CHECKMATE
1974 : (gameInfo.variant == VariantXiangqi || gameInfo.variant == VariantShatranj || IS_SHOGI(gameInfo.variant)) ?
1975 MT_STAINMATE : MT_STALEMATE;
1980 extern void DisambiguateCallback P((Board board, int flags, ChessMove kind,
1981 int rf, int ff, int rt, int ft,
1985 DisambiguateCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1987 register DisambiguateClosure *cl = (DisambiguateClosure *) closure;
1988 int wildCard = FALSE; ChessSquare piece = board[rf][ff];
1989 extern int kifu; // in parser.c
1991 // [HGM] wild: for wild-card pieces rt and rf are dummies
1992 if(piece == WhiteFalcon || piece == BlackFalcon ||
1993 piece == WhiteCobra || piece == BlackCobra)
1996 if ((cl->pieceIn == EmptySquare || cl->pieceIn == board[rf][ff]
1997 || PieceToChar(board[rf][ff]) == '~'
1998 && cl->pieceIn == (ChessSquare)(DEMOTED board[rf][ff])
2000 (cl->rfIn == -1 || cl->rfIn == rf) &&
2001 (cl->ffIn == -1 || cl->ffIn == ff) &&
2002 (cl->rtIn == -1 || cl->rtIn == rt || wildCard) &&
2003 (cl->ftIn == -1 || cl->ftIn == ft || wildCard)) {
2005 if(cl->count && rf == cl->rf && ff == cl->ff) return; // duplicate move
2007 if(cl->count == 1 && kifu & 0x7E && cl->rfIn == -1 && cl->ffIn == -1) { // traditional Shogi disambiguation required
2008 int this = 1, other = 1;
2009 if(kifu & 2) this &= (flags & 1 ? rt > rf : rt < rf), other &= (flags & 1 ? cl->rt > cl->rf : cl->rt < cl->rf);
2010 if(kifu & 4) this &= (flags & 1 ? rt < rf : rt > rf), other &= (flags & 1 ? cl->rt < cl->rf : cl->rt > cl->rf);
2011 if(kifu & 8) this &= (rf == rt), other &= (cl->rt == cl->rf);
2012 if(kifu & 0x10) this &= (flags & 1 ? ft <= ff : ft >= ff), other &= (flags & 1 ? cl->ft <= cl->ff : cl->ft >= cl->ff);
2013 if(kifu & 0x20) this &= (flags & 1 ? ft >= ff : ft <= ff), other &= (flags & 1 ? cl->ft >= cl->ff : cl->ft <= cl->ff);
2014 if(kifu & 0x40) this &= (ft == ff), other &= (cl->ft == cl->ff); // should never be used
2015 if(!other) cl->count--; // the old move did not satisfy the requested relative position, erase it
2016 if(!this) return; // the current move does not satisfy the requested relative position, ignore it
2020 if(cl->count == 1 || board[rt][ft] != EmptySquare) {
2021 // [HGM] oneclick: if multiple moves, be sure we remember capture
2022 cl->piece = board[rf][ff];
2025 cl->rt = wildCard ? cl->rtIn : rt;
2026 cl->ft = wildCard ? cl->ftIn : ft;
2029 cl->captures += (board[rt][ft] != EmptySquare); // [HGM] oneclick: count captures
2034 Disambiguate (Board board, int flags, DisambiguateClosure *closure)
2036 int illegal = 0; char c = closure->promoCharIn;
2038 if(quickFlag) flags = flags & ~1 | quickFlag & 1; // [HGM] speed: in quick mode quickFlag specifies side-to-move.
2039 closure->count = closure->captures = 0;
2040 closure->rf = closure->ff = closure->rt = closure->ft = 0;
2041 closure->kind = ImpossibleMove;
2042 rFilter = closure->rtIn; // [HGM] speed: only consider moves to given to-square
2043 fFilter = closure->ftIn;
2044 if(quickFlag) { // [HGM] speed: try without check test first, because if that is not ambiguous, we are happy
2045 GenLegal(board, flags|F_IGNORE_CHECK, DisambiguateCallback, (VOIDSTAR) closure, closure->pieceIn);
2046 if(closure->count > 1) { // gamble did not pay off. retry with check test to resolve ambiguity
2047 closure->count = closure->captures = 0;
2048 closure->rf = closure->ff = closure->rt = closure->ft = 0;
2049 closure->kind = ImpossibleMove;
2050 GenLegal(board, flags, DisambiguateCallback, (VOIDSTAR) closure, closure->pieceIn); // [HGM] speed: only pieces of requested type
2053 GenLegal(board, flags, DisambiguateCallback, (VOIDSTAR) closure, closure->pieceIn); // [HGM] speed: only pieces of requested type
2054 if (closure->count == 0) {
2055 /* See if it's an illegal move due to check */
2057 GenLegal(board, flags|F_IGNORE_CHECK, DisambiguateCallback, (VOIDSTAR) closure, closure->pieceIn);
2058 if (closure->count == 0) {
2059 /* No, it's not even that */
2060 if(!appData.testLegality && !pieceDefs && closure->pieceIn != EmptySquare) {
2061 int f, r; // if there is only a single piece of the requested type on the board, use that
2062 closure->rt = closure->rtIn, closure->ft = closure->ftIn;
2063 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++)
2064 if(board[r][f] == closure->pieceIn) closure->count++, closure->rf = r, closure->ff = f;
2065 if(closure->count > 1) illegal = 0; // ambiguous
2067 if(closure->count == 0) {
2068 if (appData.debugMode) { int i, j;
2069 for(i=BOARD_HEIGHT-1; i>=0; i--) {
2070 for(j=0; j<BOARD_WIDTH; j++)
2071 fprintf(debugFP, "%3d", (int) board[i][j]);
2072 fprintf(debugFP, "\n");
2078 } else if(pieceDefs && closure->count > 1) { // [HGM] gen: move is ambiguous under engine-defined rules
2079 DisambiguateClosure spare = *closure;
2080 pieceDefs = FALSE; spare.count = 0; // See if the (erroneous) built-in rules would resolve that
2081 GenLegal(board, flags, DisambiguateCallback, (VOIDSTAR) &spare, closure->pieceIn);
2082 if(spare.count == 1) *closure = spare; // It does, so use those in stead (game from file saved before gen patch?)
2086 if (c == 'x') c = NULLCHAR; // get rid of any 'x' (which should never happen?)
2087 if(gameInfo.variant == VariantSChess && c && c != '=' && closure->piece != WhitePawn && closure->piece != BlackPawn) {
2088 if(closure->piece < BlackPawn) { // white
2089 if(closure->rf != 0) closure->kind = IllegalMove; // must be on back rank
2090 if(!(board[VIRGIN][closure->ff] & VIRGIN_W)) closure->kind = IllegalMove; // non-virgin
2091 if(board[PieceToNumber(CharToPiece(ToUpper(c)))][BOARD_WIDTH-2] == 0) closure->kind = ImpossibleMove;// must be in stock
2092 if(closure->kind == WhiteHSideCastleFR && (closure->ff == BOARD_RGHT-2 || closure->ff == BOARD_RGHT-3)) closure->kind = ImpossibleMove;
2093 if(closure->kind == WhiteASideCastleFR && (closure->ff == BOARD_LEFT+2 || closure->ff == BOARD_LEFT+3)) closure->kind = ImpossibleMove;
2095 if(closure->rf != BOARD_HEIGHT-1) closure->kind = IllegalMove;
2096 if(!(board[VIRGIN][closure->ff] & VIRGIN_B)) closure->kind = IllegalMove; // non-virgin
2097 if(board[BOARD_HEIGHT-1-PieceToNumber(CharToPiece(ToLower(c)))][1] == 0) closure->kind = ImpossibleMove;
2098 if(closure->kind == BlackHSideCastleFR && (closure->ff == BOARD_RGHT-2 || closure->ff == BOARD_RGHT-3)) closure->kind = ImpossibleMove;
2099 if(closure->kind == BlackASideCastleFR && (closure->ff == BOARD_LEFT+2 || closure->ff == BOARD_LEFT+3)) closure->kind = ImpossibleMove;
2102 if(gameInfo.variant == VariantChu) {
2103 if(c == '+') closure->kind = (flags & F_WHITE_ON_MOVE ? WhitePromotion : BlackPromotion); // for now, accept any
2105 if(gameInfo.variant == VariantShogi) {
2106 /* [HGM] Shogi promotions. On input, '=' means defer, '+' promote. Afterwards, c is set to '+' for promotions, NULL other */
2107 if(closure->rfIn != DROP_RANK && closure->kind == NormalMove) {
2108 ChessSquare piece = closure->piece;
2109 int zone = BOARD_HEIGHT/3 + (BOARD_HEIGHT == 8);
2110 if (c == 'd' && (piece == WhiteRook || piece == BlackRook) ||
2111 c == 'h' && (piece == WhiteBishop || piece == BlackBishop) ||
2112 c == 'g' && (piece <= WhiteFerz || piece <= BlackFerz && piece >= BlackPawn) )
2113 c = '+'; // allowed ICS notations
2114 if(c != NULLCHAR && c != '+' && c != '=') closure->kind = IllegalMove; // otherwise specifying a piece is illegal
2115 else if(flags & F_WHITE_ON_MOVE) {
2116 if( (int) piece < (int) WhiteWazir &&
2117 (closure->rf >= BOARD_HEIGHT-zone || closure->rt >= BOARD_HEIGHT-zone) ) {
2118 if( (piece == WhitePawn || piece == WhiteQueen) && closure->rt > BOARD_HEIGHT-2 ||
2119 piece == WhiteKnight && closure->rt > BOARD_HEIGHT-3) /* promotion mandatory */
2120 closure->kind = c == '=' ? IllegalMove : WhitePromotion;
2121 else /* promotion optional, default is defer */
2122 closure->kind = c == '+' ? WhitePromotion : WhiteNonPromotion;
2123 } else closure->kind = c == '+' ? IllegalMove : NormalMove;
2125 if( (int) piece < (int) BlackWazir && (closure->rf < zone || closure->rt < zone) ) {
2126 if( (piece == BlackPawn || piece == BlackQueen) && closure->rt < 1 ||
2127 piece == BlackKnight && closure->rt < 2 ) /* promotion obligatory */
2128 closure->kind = c == '=' ? IllegalMove : BlackPromotion;
2129 else /* promotion optional, default is defer */
2130 closure->kind = c == '+' ? BlackPromotion : BlackNonPromotion;
2131 } else closure->kind = c == '+' ? IllegalMove : NormalMove;
2134 if(closure->kind == WhitePromotion || closure->kind == BlackPromotion) c = '+'; else
2135 if(closure->kind == WhiteNonPromotion || closure->kind == BlackNonPromotion) c = '=';
2137 if (closure->kind == WhitePromotion || closure->kind == BlackPromotion) {
2138 if(c == NULLCHAR) { // missing promoChar on mandatory promotion; use default for variant
2139 if(gameInfo.variant == VariantShatranj || gameInfo.variant == VariantCourier ||
2140 gameInfo.variant == VariantMakruk || gameInfo.variant == VariantASEAN)
2141 c = PieceToChar(BlackFerz);
2142 else if(gameInfo.variant == VariantGreat)
2143 c = PieceToChar(BlackMan);
2144 else if(gameInfo.variant == VariantGrand)
2145 closure->kind = closure->rt != 0 && closure->rt != BOARD_HEIGHT-1 ? NormalMove : AmbiguousMove; // no default in Grand Chess
2147 c = PieceToChar(BlackQueen);
2148 } else if(c == '=') closure->kind = IllegalMove; // no deferral outside Shogi
2149 else if(c == 'l' && gameInfo.variant == VariantChuChess && HasLion(board, flags)) closure->kind = IllegalMove;
2150 } else if (c == '+') { // '+' outside shogi, check if pieceToCharTable enabled it
2151 ChessSquare p = closure->piece;
2152 if(p > WhiteMan && p < BlackPawn || p > BlackMan || PieceToChar(PROMOTED p) != '+')
2153 closure->kind = ImpossibleMove; // used on non-promotable piece
2154 else if(gameInfo.variant == VariantChuChess && HasLion(board, flags)) closure->kind = IllegalMove;
2155 } else if (c != NULLCHAR) closure->kind = IllegalMove;
2157 closure->promoChar = ToLower(c); // this can be NULLCHAR! Note we keep original promoChar even if illegal.
2158 if(c != '+' && c != '=' && c != NULLCHAR && CharToPiece(flags & F_WHITE_ON_MOVE ? ToUpper(c) : ToLower(c)) == EmptySquare)
2159 closure->kind = ImpossibleMove; // but we cannot handle non-existing piece types!
2160 if (closure->count > 1) {
2161 closure->kind = AmbiguousMove;
2164 /* Note: If more than one illegal move matches, but no legal
2165 moves, we return IllegalMove, not AmbiguousMove. Caller
2166 can look at closure->count to detect this.
2168 closure->kind = IllegalMove;
2182 } CoordsToAlgebraicClosure;
2184 extern void CoordsToAlgebraicCallback P((Board board, int flags,
2185 ChessMove kind, int rf, int ff,
2186 int rt, int ft, VOIDSTAR closure));
2189 CoordsToAlgebraicCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
2191 register CoordsToAlgebraicClosure *cl =
2192 (CoordsToAlgebraicClosure *) closure;
2194 if ((rt == cl->rt && ft == cl->ft || rt == rf && ft == ff) && // [HGM] null move matches any toSquare
2195 (board[rf][ff] == cl->piece
2196 || PieceToChar(board[rf][ff]) == '~' &&
2197 (ChessSquare) (DEMOTED board[rf][ff]) == cl->piece)
2201 cl->kind = kind; /* this is the move we want */
2203 cl->file++; /* need file to rule out this move */
2207 cl->rank++; /* need rank to rule out this move */
2209 cl->either++; /* rank or file will rule out this move */
2215 /* Convert coordinates to normal algebraic notation.
2216 promoChar must be NULLCHAR or 'x' if not a promotion.
2219 CoordsToAlgebraic (Board board, int flags, int rf, int ff, int rt, int ft, int promoChar, char out[MOVE_LEN])
2223 char *outp = out, c, capture;
2224 CoordsToAlgebraicClosure cl;
2226 if (rf == DROP_RANK) {
2227 if(ff == EmptySquare) { strncpy(outp, "--",3); return NormalMove; } // [HGM] pass
2228 /* Bughouse piece drop */
2229 *outp++ = ToUpper(PieceToChar((ChessSquare) ff));
2234 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2236 return (flags & F_WHITE_ON_MOVE) ? WhiteDrop : BlackDrop;
2239 if (promoChar == 'x') promoChar = NULLCHAR;
2240 piece = board[rf][ff];
2241 if(PieceToChar(piece)=='~') piece = (ChessSquare)(DEMOTED piece);
2246 kind = LegalityTest(board, flags, rf, ff, rt, ft, promoChar);
2247 if (kind == IllegalMove && !(flags&F_IGNORE_CHECK)) {
2248 /* Keep short notation if move is illegal only because it
2249 leaves the player in check, but still return IllegalMove */
2250 kind = LegalityTest(board, flags|F_IGNORE_CHECK, rf, ff, rt, ft, promoChar);
2251 if (kind == IllegalMove) break;
2256 capture = board[rt][ft] != EmptySquare || kind == WhiteCapturesEnPassant || kind == BlackCapturesEnPassant;
2257 if (ff == ft && !capture) { /* [HGM] Xiangqi has straight noncapts! */
2258 /* Non-capture; use style "e5" */
2261 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2263 /* Capture; use style "exd5" */
2265 *outp++ = 'x'; /* [HGM] Xiangqi has sideway noncaptures across river! */
2269 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2271 /* Use promotion suffix style "=Q" */
2273 if (promoChar != NULLCHAR) {
2274 if(IS_SHOGI(gameInfo.variant)) {
2275 /* [HGM] ... but not in Shogi! */
2276 *outp++ = promoChar == '=' ? '=' : '+';
2279 *outp++ = ToUpper(promoChar);
2288 /* Fabien moved code: FRC castling first (if KxR), wild castling second */
2289 /* Code added by Tord: FRC castling. */
2290 if((piece == WhiteKing && board[rt][ft] == WhiteRook) ||
2291 (piece == BlackKing && board[rt][ft] == BlackRook)) {
2293 safeStrCpy(out, "O-O", MOVE_LEN);
2295 safeStrCpy(out, "O-O-O", MOVE_LEN);
2296 return LegalityTest(board, flags, rf, ff, rt, ft, promoChar);
2298 /* End of code added by Tord */
2299 /* Test for castling or ICS wild castling */
2300 /* Use style "O-O" (oh-oh) for PGN compatibility */
2301 else if (rf == rt &&
2302 rf == ((piece == WhiteKing) ? 0 : BOARD_HEIGHT-1) &&
2303 (ft - ff > 1 || ff - ft > 1) && // No castling if legal King move (on narrow boards!)
2304 ((ff == BOARD_WIDTH>>1 && (ft == BOARD_LEFT+2 || ft == BOARD_RGHT-2)) ||
2305 (ff == (BOARD_WIDTH-1)>>1 && (ft == BOARD_LEFT+1 || ft == BOARD_RGHT-3)))) {
2306 if(ft==BOARD_LEFT+1 || ft==BOARD_RGHT-2)
2307 snprintf(out, MOVE_LEN, "O-O%c%c", promoChar ? '/' : 0, ToUpper(promoChar));
2309 snprintf(out, MOVE_LEN, "O-O-O%c%c", promoChar ? '/' : 0, ToUpper(promoChar));
2311 /* This notation is always unambiguous, unless there are
2312 kings on both the d and e files, with "wild castling"
2313 possible for the king on the d file and normal castling
2314 possible for the other. ICS rules for wild 9
2315 effectively make castling illegal for either king in
2316 this situation. So I am not going to worry about it;
2317 I'll just generate an ambiguous O-O in this case.
2319 return LegalityTest(board, flags, rf, ff, rt, ft, promoChar);
2322 /* else fall through */
2327 cl.rt = rFilter = rt; // [HGM] speed: filter on to-square
2328 cl.ft = fFilter = ft;
2330 cl.kind = IllegalMove;
2331 cl.rank = cl.file = cl.either = 0;
2332 c = PieceToChar(piece) ;
2333 GenLegal(board, flags, CoordsToAlgebraicCallback, (VOIDSTAR) &cl, c!='~' ? piece : (DEMOTED piece)); // [HGM] speed
2335 if (cl.kind == IllegalMove && !(flags&F_IGNORE_CHECK)) {
2336 /* Generate pretty moves for moving into check, but
2337 still return IllegalMove.
2339 GenLegal(board, flags|F_IGNORE_CHECK, CoordsToAlgebraicCallback, (VOIDSTAR) &cl, c!='~' ? piece : (DEMOTED piece));
2340 if (cl.kind == IllegalMove) break;
2341 cl.kind = IllegalMove;
2344 /* Style is "Nf3" or "Nxf7" if this is unambiguous,
2345 else "Ngf3" or "Ngxf7",
2346 else "N1f3" or "N5xf7",
2347 else "Ng1f3" or "Ng5xf7".
2349 if( c == '~' || c == '+') {
2350 /* [HGM] print nonexistent piece as its demoted version */
2351 piece = (ChessSquare) (DEMOTED piece - 11*(gameInfo.variant == VariantChu));
2353 if(c=='+') *outp++ = c;
2354 *outp++ = ToUpper(PieceToChar(piece));
2355 if(*outp = PieceSuffix(piece)) outp++;
2357 if (cl.file || (cl.either && !cl.rank)) {
2363 else { *outp++ = (rf+ONE-'0')/10 + '0';*outp++ = (rf+ONE-'0')%10 + '0'; }
2366 if(board[rt][ft] != EmptySquare)
2372 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2373 if (IS_SHOGI(gameInfo.variant)) {
2374 /* [HGM] in Shogi non-pawns can promote */
2375 *outp++ = promoChar; // Don't bother to correct move type, return value is never used!
2377 else if (gameInfo.variant == VariantChuChess && promoChar ||
2378 gameInfo.variant != VariantSuper && promoChar &&
2379 (piece == WhiteLance || piece == BlackLance) ) { // Lance sometimes represents Pawn
2381 *outp++ = ToUpper(promoChar);
2383 else if (gameInfo.variant == VariantSChess && promoChar) { // and in S-Chess we have gating
2385 *outp++ = ToUpper(promoChar);
2391 /* Moving a nonexistent piece */
2395 /* Not a legal move, even ignoring check.
2396 If there was a piece on the from square,
2397 use style "Ng1g3" or "Ng1xe8";
2398 if there was a pawn or nothing (!),
2399 use style "g1g3" or "g1xe8". Use "x"
2400 if a piece was on the to square, even
2401 a piece of the same color.
2405 if (piece != EmptySquare && piece != WhitePawn && piece != BlackPawn) {
2407 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<=BOARD_RGHT; f++)
2408 c += (board[r][f] == piece); // count on-board pieces of given type
2409 *outp++ = ToUpper(PieceToChar(piece));
2411 if(c != 1) { // [HGM] but if there is only one piece of the mentioned type, no from-square, thank you!
2415 else { *outp++ = (rf+ONE-'0')/10 + '0';*outp++ = (rf+ONE-'0')%10 + '0'; }
2417 if (board[rt][ft] != EmptySquare) *outp++ = 'x';
2421 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2422 /* Use promotion suffix style "=Q" */
2423 if (promoChar != NULLCHAR && promoChar != 'x') {
2425 *outp++ = ToUpper(promoChar);
2432 // [HGM] XQ: the following code serves to detect perpetual chasing (Asian rules)
2441 // I guess the following variables logically belong in the closure too, but I was too lazy and used globals
2443 int preyStackPointer, chaseStackPointer;
2446 unsigned char rf, ff, rt, ft;
2450 unsigned char rank, file;
2456 // there are three new callbacks for use with GenLegal: for adding captures, deleting them, and finding a recapture
2458 extern void AtacksCallback P((Board board, int flags, ChessMove kind,
2459 int rf, int ff, int rt, int ft,
2463 AttacksCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
2464 { // For adding captures that can lead to chase indictment to the chaseStack
2465 if(board[rt][ft] == EmptySquare) return; // non-capture
2466 if(board[rt][ft] == WhitePawn && rt < BOARD_HEIGHT/2) return; // Pawn before river can be chased
2467 if(board[rt][ft] == BlackPawn && rt >= BOARD_HEIGHT/2) return; // Pawn before river can be chased
2468 if(board[rf][ff] == WhitePawn || board[rf][ff] == BlackPawn) return; // Pawns are allowed to chase
2469 if(board[rf][ff] == WhiteWazir || board[rf][ff] == BlackWazir) return; // King is allowed to chase
2470 // move cannot be excluded from being a chase trivially (based on attacker and victim); save it on chaseStack
2471 chaseStack[chaseStackPointer].rf = rf;
2472 chaseStack[chaseStackPointer].ff = ff;
2473 chaseStack[chaseStackPointer].rt = rt;
2474 chaseStack[chaseStackPointer].ft = ft;
2475 chaseStackPointer++;
2478 extern void ExistingAtacksCallback P((Board board, int flags, ChessMove kind,
2479 int rf, int ff, int rt, int ft,
2483 ExistingAttacksCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
2484 { // for removing pre-exsting captures from the chaseStack, to be left with newly created ones
2486 register ChaseClosure *cl = (ChaseClosure *) closure; //closure tells us the move played in the repeat loop
2488 if(board[rt][ft] == EmptySquare) return; // no capture
2489 if(rf == cl->rf && ff == cl->ff) { // attacks with same piece from new position are not considered new
2490 rf = cl->rt; ff = cl->ft; // doctor their fromSquare so they will be recognized in chaseStack
2492 // search move in chaseStack, and delete it if it occurred there (as we know now it is not a new capture)
2493 for(i=0; i<chaseStackPointer; i++) {
2494 if(chaseStack[i].rf == rf && chaseStack[i].ff == ff &&
2495 chaseStack[i].rt == rt && chaseStack[i].ft == ft ) {
2496 // move found on chaseStack, delete it by overwriting with move popped from top of chaseStack
2497 chaseStack[i] = chaseStack[--chaseStackPointer];
2503 extern void ProtectedCallback P((Board board, int flags, ChessMove kind,
2504 int rf, int ff, int rt, int ft,
2508 ProtectedCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
2509 { // for determining if a piece (given through the closure) is protected
2510 register ChaseClosure *cl = (ChaseClosure *) closure; // closure tells us where to recapture
2512 if(rt == cl->rt && ft == cl->ft) cl->recaptures++; // count legal recaptures to this square
2513 if(appData.debugMode && board[rt][ft] != EmptySquare)
2514 fprintf(debugFP, "try %c%c%c%c=%d\n", ff+AAA, rf+ONE,ft+AAA, rt+ONE, cl->recaptures);
2517 extern char moveList[MAX_MOVES][MOVE_LEN];
2520 PerpetualChase (int first, int last)
2521 { // this routine detects if the side to move in the 'first' position is perpetually chasing (when not checking)
2524 ChessSquare captured;
2526 preyStackPointer = 0; // clear stack of chased pieces
2527 for(i=first; i<last; i+=2) { // for all positions with same side to move
2528 if(appData.debugMode) fprintf(debugFP, "judge position %i\n", i);
2529 chaseStackPointer = 0; // clear stack that is going to hold possible chases
2530 // determine all captures possible after the move, and put them on chaseStack
2531 GenLegal(boards[i+1], PosFlags(i), AttacksCallback, &cl, EmptySquare);
2532 if(appData.debugMode) { int n;
2533 for(n=0; n<chaseStackPointer; n++)
2534 fprintf(debugFP, "%c%c%c%c ", chaseStack[n].ff+AAA, chaseStack[n].rf+ONE,
2535 chaseStack[n].ft+AAA, chaseStack[n].rt+ONE);
2536 fprintf(debugFP, ": all capts\n");
2538 // determine all captures possible before the move, and delete them from chaseStack
2539 cl.rf = moveList[i][1]-ONE; // prepare closure to pass move that led from i to i+1
2540 cl.ff = moveList[i][0]-AAA+BOARD_LEFT;
2541 cl.rt = moveList[i][3]-ONE;
2542 cl.ft = moveList[i][2]-AAA+BOARD_LEFT;
2543 CopyBoard(xqCheckers, nullBoard); xqCheckers[EP_STATUS] = 1; // giant kludge to make GenLegal ignore pre-existing checks
2544 GenLegal(boards[i], PosFlags(i), ExistingAttacksCallback, &cl, EmptySquare);
2545 xqCheckers[EP_STATUS] = 0; // disable the generation of quasi-legal moves again
2546 if(appData.debugMode) { int n;
2547 for(n=0; n<chaseStackPointer; n++)
2548 fprintf(debugFP, "%c%c%c%c ", chaseStack[n].ff+AAA, chaseStack[n].rf+ONE,
2549 chaseStack[n].ft+AAA, chaseStack[n].rt+ONE);
2550 fprintf(debugFP, ": new capts after %c%c%c%c\n", cl.ff+AAA, cl.rf+ONE, cl.ft+AAA, cl.rt+ONE);
2552 // chaseSack now contains all captures made possible by the move
2553 for(j=0; j<chaseStackPointer; j++) { // run through chaseStack to identify true chases
2554 int attacker = (int)boards[i+1][chaseStack[j].rf][chaseStack[j].ff];
2555 int victim = (int)boards[i+1][chaseStack[j].rt][chaseStack[j].ft];
2557 if(attacker >= (int) BlackPawn) attacker = BLACK_TO_WHITE attacker; // convert to white, as piecee type
2558 if(victim >= (int) BlackPawn) victim = BLACK_TO_WHITE victim;
2560 if((attacker == WhiteKnight || attacker == WhiteCannon) && victim == WhiteRook)
2561 continue; // C or H attack on R is always chase; leave on chaseStack
2563 if(attacker == victim) {
2564 if(LegalityTest(boards[i+1], PosFlags(i+1), chaseStack[j].rt,
2565 chaseStack[j].ft, chaseStack[j].rf, chaseStack[j].ff, NULLCHAR) == NormalMove) {
2566 // we can capture back with equal piece, so this is no chase but a sacrifice
2567 chaseStack[j] = chaseStack[--chaseStackPointer]; // delete the capture from the chaseStack
2568 j--; /* ! */ continue;
2573 // the attack is on a lower piece, or on a pinned or blocked equal one
2574 CopyBoard(xqCheckers, nullBoard); xqCheckers[EP_STATUS] = 1;
2575 CheckTest(boards[i+1], PosFlags(i+1), -1, -1, -1, -1, FALSE); // if we deliver check with our move, the checkers get marked
2576 // test if the victim is protected by a true protector. First make the capture.
2577 captured = boards[i+1][chaseStack[j].rt][chaseStack[j].ft];
2578 boards[i+1][chaseStack[j].rt][chaseStack[j].ft] = boards[i+1][chaseStack[j].rf][chaseStack[j].ff];
2579 boards[i+1][chaseStack[j].rf][chaseStack[j].ff] = EmptySquare;
2580 // Then test if the opponent can recapture
2581 cl.recaptures = 0; // prepare closure to pass recapture square and count moves to it
2582 cl.rt = chaseStack[j].rt;
2583 cl.ft = chaseStack[j].ft;
2584 if(appData.debugMode) {
2585 fprintf(debugFP, "test if we can recapture %c%c\n", cl.ft+AAA, cl.rt+ONE);
2587 xqCheckers[EP_STATUS] = 2; // causes GenLegal to ignore the checks we delivered with the move, in real life evaded before we captured
2588 GenLegal(boards[i+1], PosFlags(i+1), ProtectedCallback, &cl, EmptySquare); // try all moves
2589 xqCheckers[EP_STATUS] = 0; // disable quasi-legal moves again
2590 // unmake the capture
2591 boards[i+1][chaseStack[j].rf][chaseStack[j].ff] = boards[i+1][chaseStack[j].rt][chaseStack[j].ft];
2592 boards[i+1][chaseStack[j].rt][chaseStack[j].ft] = captured;
2593 // if a recapture was found, piece is protected, and we are not chasing it.
2594 if(cl.recaptures) { // attacked piece was defended by true protector, no chase
2595 chaseStack[j] = chaseStack[--chaseStackPointer]; // so delete from chaseStack
2599 // chaseStack now contains all moves that chased
2600 if(appData.debugMode) { int n;
2601 for(n=0; n<chaseStackPointer; n++)
2602 fprintf(debugFP, "%c%c%c%c ", chaseStack[n].ff+AAA, chaseStack[n].rf+ONE,
2603 chaseStack[n].ft+AAA, chaseStack[n].rt+ONE);
2604 fprintf(debugFP, ": chases\n");
2606 if(i == first) { // copy all people chased by first move of repeat cycle to preyStack
2607 for(j=0; j<chaseStackPointer; j++) {
2608 preyStack[j].rank = chaseStack[j].rt;
2609 preyStack[j].file = chaseStack[j].ft;
2611 preyStackPointer = chaseStackPointer;
2614 for(j=0; j<chaseStackPointer; j++) {
2615 for(k=0; k<preyStackPointer; k++) {
2616 // search the victim of each chase move on the preyStack (first occurrence)
2617 if(chaseStack[j].ft == preyStack[k].file && chaseStack[j].rt == preyStack[k].rank ) {
2618 if(k < tail) break; // piece was already identified as still being chased
2619 preyStack[preyStackPointer] = preyStack[tail]; // move chased piece to bottom part of preyStack
2620 preyStack[tail] = preyStack[k]; // by swapping
2621 preyStack[k] = preyStack[preyStackPointer];
2627 preyStackPointer = tail; // keep bottom part of preyStack, popping pieces unchased on move i.
2628 if(appData.debugMode) { int n;
2629 for(n=0; n<preyStackPointer; n++)
2630 fprintf(debugFP, "%c%c ", preyStack[n].file+AAA, preyStack[n].rank+ONE);
2631 fprintf(debugFP, "always chased upto ply %d\n", i);
2633 // now adjust the location of the chased pieces according to opponent move
2634 for(j=0; j<preyStackPointer; j++) {
2635 if(preyStack[j].rank == moveList[i+1][1]-ONE &&
2636 preyStack[j].file == moveList[i+1][0]-AAA+BOARD_LEFT) {
2637 preyStack[j].rank = moveList[i+1][3]-ONE;
2638 preyStack[j].file = moveList[i+1][2]-AAA+BOARD_LEFT;
2643 return preyStackPointer ? 256*(preyStack[preyStackPointer].file - BOARD_LEFT + AAA) + (preyStack[preyStackPointer].rank + ONE)
2644 : 0; // if any piece was left on preyStack, it has been perpetually chased,and we return the