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
26 * ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL
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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 char pieceToChar[] = {
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 char pieceNickName[EmptySquare];
126 PieceToChar (ChessSquare p)
128 if((int)p < 0 || (int)p >= (int)EmptySquare) return('x'); /* [HGM] for safety */
129 return pieceToChar[(int) p];
133 PieceToNumber (ChessSquare p) /* [HGM] holdings: count piece type, ignoring non-participating piece types */
136 ChessSquare start = (int)p >= (int)BlackPawn ? BlackPawn : WhitePawn;
138 while(start++ != p) if(pieceToChar[start-1] != '.' && pieceToChar[start-1] != '+') i++;
146 if(c == '.') return EmptySquare;
147 for(i=0; i< (int) EmptySquare; i++)
148 if(pieceNickName[i] == c) return (ChessSquare) i;
149 for(i=0; i< (int) EmptySquare; i++)
150 if(pieceToChar[i] == c) return (ChessSquare) i;
155 CopyBoard (Board to, Board from)
159 for (i = 0; i < BOARD_HEIGHT; i++)
160 for (j = 0; j < BOARD_WIDTH; j++)
161 to[i][j] = from[i][j];
162 for (j = 0; j < BOARD_FILES; j++) // [HGM] gamestate: copy castling rights and ep status
163 to[VIRGIN][j] = from[VIRGIN][j],
164 to[CASTLING][j] = from[CASTLING][j];
165 to[HOLDINGS_SET] = 0; // flag used in ICS play
169 CompareBoards (Board board1, Board board2)
173 for (i = 0; i < BOARD_HEIGHT; i++)
174 for (j = 0; j < BOARD_WIDTH; j++) {
175 if (board1[i][j] != board2[i][j])
181 char defaultName[] = "PNBRQ......................................K" // white
182 "pnbrq......................................k"; // black
183 char shogiName[] = "PNBRLS...G.++++++..........................K" // white
184 "pnbrls...g.++++++..........................k"; // black
185 char xqName[] = "PH.R.AE..K.C................................" // white
186 "ph.r.ae..k.c................................"; // black
189 CollectPieceDescriptors ()
190 { // make a line of piece descriptions for use in the PGN Piece tag:
191 // dump all engine defined pieces, and pieces with non-standard names,
192 // but suppress black pieces that are the same as their white counterpart
194 static char buf[MSG_SIZ];
195 char *m, c, d, *pieceName = defaultName;
198 if(!pieceDefs) return "";
199 if(gameInfo.variant == VariantChu) return ""; // for now don't do this for Chu Shogi
200 if(gameInfo.variant == VariantShogi) pieceName = shogiName;
201 if(gameInfo.variant == VariantXiangqi) pieceName = xqName;
202 for(p=WhitePawn; p<EmptySquare; p++) {
203 if((c = pieceToChar[p]) == '.' || c == '~') continue; // does not participate
204 m = pieceDesc[p]; d = (c == '+' ? pieceToChar[DEMOTED p] : c);
205 if(p >= BlackPawn && pieceToChar[BLACK_TO_WHITE p] == toupper(c)
206 && (c != '+' || pieceToChar[DEMOTED BLACK_TO_WHITE p] == d)) { // black member of normal pair
207 char *wm = pieceDesc[BLACK_TO_WHITE p];
208 if(!m && !wm || m && wm && !strcmp(wm, m)) continue; // moves as a white piece
209 } else // white or unpaired black
210 if((p < BlackPawn || CharToPiece(toupper(d)) != EmptySquare) && // white or lone black
211 !pieceDesc[p] /*&& pieceName[p] == c*/) continue; // orthodox piece known by its usual name
212 // TODO: listing pieces because of unusual name can only be done if we have accurate Betza of all defaults
213 if(!m) m = defaultDesc[p];
215 snprintf(buf+len, MSG_SIZ-len, "%s%s%c:%s", len ? ";" : "", c == '+' ? "+" : "", d, m);
220 // [HGM] gen: configurable move generation from Betza notation sent by engine.
221 // Some notes about two-leg moves: GenPseudoLegal() works in two modes, depending on whether a 'kill-
222 // square has been set: without one is generates all moves, and a global int legNr flags in bits 0 and 1
223 // if the move has 1 or 2 legs. Only the marking of squares makes use of this info, by only marking
224 // target squares of leg 1 (rejecting null move). A dummy move with MoveType 'FirstLeg' to the relay square
225 // is generated, so a cyan marker can be put there, and other functions can ignore such a move. When the
226 // user selects this square, it becomes the kill-square. Once a kill-square is set, only 2-leg moves are
227 // generated that use that square as relay, plus 1-leg moves, so the 1-leg move that goes to the kill-square
228 // can be marked during 2nd-leg entry to terminate the move there. For judging the pseudo-legality of the
229 // 2nd leg, the from-square has to be considered empty, although the moving piece is still on it.
233 // alphabet "abcdefghijklmnopqrstuvwxyz"
234 char symmetry[] = "FBNW.FFW.NKN.NW.QR....W..N";
235 char xStep[] = "2110.130.102.10.00....0..2";
236 char yStep[] = "2132.133.313.20.11....1..3";
237 char dirType[] = "01000104000200000260050000";
238 char upgrade[] = "AFCD.BGH.JQL.NO.KW....R..Z";
240 // 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 "
241 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 };
242 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 };
244 int rot[][4] = { // rotation matrices for each direction
256 OK (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR cl)
262 MovesFromString (Board board, int flags, int f, int r, int tx, int ty, int angle, char *desc, MoveCallback cb, VOIDSTAR cl)
264 char buf[80], *p = desc;
265 int mine, his, dir, bit, occup, i;
266 if(flags & F_WHITE_ON_MOVE) his = 2, mine = 1; else his = 1, mine = 2;
267 while(*p) { // more moves to go
268 int expo = 1, dx, dy, x, y, mode, dirSet, retry=0, initial=0, jump=1, skip = 0;
270 if(*p == 'i') initial = 1, desc = ++p;
271 while(islower(*p)) p++; // skip prefixes
272 if(!isupper(*p)) return; // syntax error: no atom
273 dirSet = 0; // build direction set based on atom symmetry
274 switch(symmetry[*p-'A']) {
275 case 'B': expo = 0; // bishop, slide
276 case 'F': // diagonal atom (degenerate 4-fold)
277 if(tx < 0) { // for continuation legs relative directions are orthogonal!
278 while(islower(*desc) && (i = dirType[*desc-'a']) != '0') {
279 int b = dirs1[*desc-'a']; // use wide version
280 if( islower(desc[1]) &&
281 ((i | dirType[desc[1]-'a']) & 3) == 3) { // combinable (perpendicular dim)
282 b = dirs1[*desc-'a'] & dirs1[desc[1]-'a']; // intersect wide & perp wide
287 dirSet &= 0x55; if(!dirSet) dirSet = 0x55;
290 case 'R': expo = 0; // rook, slide
291 case 'W': // orthogonal atom (non-deg 4-fold)
292 while(islower(*desc) && (dirType[*desc-'a'] & ~4) != '0') dirSet |= dirs2[*desc++-'a'];
293 dirSet &= 0x55; if(!dirSet) dirSet = 0x55;
294 dirSet = (dirSet << angle | dirSet >> 8-angle) & 255; // re-orient direction system
296 case 'N': // oblique atom (degenerate 8-fold)
297 while(islower(*desc) && (i = dirType[*desc-'a']) != '0') {
298 int b = dirs2[*desc-'a']; // when alone, use narrow version
299 if(desc[1] == 'h') b = dirs1[*desc-'a'], desc += 2; // dirs1 is wide version
300 else if(*desc == desc[1] || islower(desc[1]) && i < '4'
301 && ((i | dirType[desc[1]-'a']) & 3) == 3) { // combinable (perpendicular dim or same)
302 b = dirs1[*desc-'a'] & dirs2[desc[1]-'a']; // intersect wide & perp narrow
307 if(!dirSet) dirSet = 0xFF;
309 case 'Q': expo = 0; // queen, slide
310 case 'K': // non-deg (pseudo) 8-fold
311 dirSet=0x55; // start with orthogonal moves
312 retry = 1; // and schedule the diagonal moves for later
313 break; // should not have direction indicators
314 default: return; // syntax error: invalid atom
316 if(mine == 2 && tx < 0) dirSet = dirSet >> 4 | dirSet << 4 & 255; // invert black moves
317 mode = 0; // build mode mask
318 if(*desc == 'm') mode |= 4, desc++;
319 if(*desc == 'c') mode |= his, desc++;
320 if(*desc == 'd') mode |= mine, desc++;
321 if(*desc == 'e') mode |= 8, desc++;
322 if(*desc == 'p') mode |= 32, desc++;
323 if(*desc == 'g') mode |= 64, desc++;
324 if(*desc == 'o') mode |= 128, desc++;
325 if(*desc == 'y') mode |= 512, desc++;
326 if(*desc == 'n') jump = 0, desc++;
327 while(*desc == 'j') jump++, desc++;
328 if(*desc == 'a') cont = ++desc;
329 dx = xStep[*p-'A'] - '0'; // step vector of atom
330 dy = yStep[*p-'A'] - '0';
331 if(isdigit(*++p)) expo = atoi(p++); // read exponent
332 if(expo > 9) p++; // allow double-digit
333 desc = p; // this is start of next move
334 if(initial && (board[r][f] != initialPosition[r][f] ||
335 r == 0 && board[TOUCHED_W] & 1<<f ||
336 r == BOARD_HEIGHT-1 && board[TOUCHED_B] & 1<<f ) ) continue;
337 if(expo > 1 && dx == 0 && dy == 0) { // castling indicated by O + number
341 if(!(mode & 15)) mode = his + 4; // no mode spec, use default = mc
343 if(mode & 32) mode ^= 256 + 32; // in non-final legs 'p' means 'pass through'
344 if(mode & 64 + 512) {
345 mode |= 256; // and 'g' too, but converts leaper <-> slider
346 if(mode & 512) mode ^= 0x304; // and 'y' is m-like 'g'
347 strncpy(buf, cont, 80); cont = buf; // copy next leg(s), so we can modify
348 while(islower(*cont)) cont++; // skip to atom
349 *cont = upgrade[*cont-'A']; // replace atom, BRQ <-> FWK
350 if(expo == 1) *++cont = '0'; // turn other leapers into riders
351 *++cont = '\0'; // make sure any old range is stripped off
352 cont = buf; // use modified string for continuation leg
354 if(!(mode & 0x30F)) mode = his + 0x104; // and default = mcp
356 if(dy == 1) skip = jump - 1, jump = 1; // on W & F atoms 'j' = skip first square
358 for(dir=0, bit=1; dir<8; dir++, bit += bit) { // loop over directions
359 int i = expo, j = skip, hop = mode, vx, vy;
360 if(!(bit & dirSet)) continue; // does not move in this direction
361 if(dy != 1) j = 0; //
362 vx = dx*rot[dir][0] + dy*rot[dir][1]; // rotate step vector
363 vy = dx*rot[dir][2] + dy*rot[dir][3];
364 if(tx < 0) x = f, y = r; // start square
365 else x = tx, y = ty; // from previous to-square if continuation
367 x += vx; y += vy; // step to next square
368 if(y < 0 || y >= BOARD_HEIGHT) break; // vertically off-board: always done
369 if(x < BOARD_LEFT) { if(mode & 128) x += BOARD_RGHT - BOARD_LEFT; else break; }
370 if(x >= BOARD_RGHT) { if(mode & 128) x -= BOARD_RGHT - BOARD_LEFT; else break; }
371 if(j) { j--; continue; } // skip irrespective of occupation
372 if(!jump && board[y - vy + vy/2][x - vx + vx/2] != EmptySquare) break; // blocked
373 if(jump > 1 && board[y - vy + vy/2][x - vx + vx/2] == EmptySquare) break; // no hop
374 if(x == f && y == r) occup = 4; else // start square counts as empty
375 if(board[y][x] < BlackPawn) occup = 0x101; else
376 if(board[y][x] < EmptySquare) occup = 0x102; else
378 if(cont) { // non-final leg
379 if(occup & mode) { // valid intermediate square, do continuation
380 if(occup & mode & 0x104) // no side effects, merge legs to one move
381 MovesFromString(board, flags, f, r, x, y, dir, cont, cb, cl);
382 if(occup & mode & 3 && (killX < 0 || killX == x && killY == y)) { // destructive first leg
384 MovesFromString(board, flags, f, r, x, y, dir, cont, &OK, &cnt); // count possible continuations
385 if(cnt) { // and if there are
386 if(killX < 0) cb(board, flags, FirstLeg, r, f, y, x, cl); // then generate their first leg
388 MovesFromString(board, flags, f, r, x, y, dir, cont, cb, cl);
393 if(occup != 4) break; // occupied squares always terminate the leg
396 if(hop & 32+64) { if(occup != 4) { if(hop & 64 && i != 1) i = 2; hop &= 31; } continue; } // hopper
397 if(mode & 8 && y == board[EP_RANK] && occup == 4 && board[EP_FILE] == x) { // to e.p. square
398 cb(board, flags, mine == 1 ? WhiteCapturesEnPassant : BlackCapturesEnPassant, r, f, y, x, cl);
400 if(mode & 16) { // castling
401 i = 2; // kludge to elongate move indefinitely
402 if(occup == 4) continue; // skip empty squares
403 if(x == BOARD_LEFT && board[y][x] == initialPosition[y][x]) // reached initial corner piece
404 cb(board, flags, mine == 1 ? WhiteQueenSideCastle : BlackQueenSideCastle, r, f, y, f - expo, cl);
405 if(x == BOARD_RGHT-1 && board[y][x] == initialPosition[y][x])
406 cb(board, flags, mine == 1 ? WhiteKingSideCastle : BlackKingSideCastle, r, f, y, f + expo, cl);
409 if(occup & mode) cb(board, flags, NormalMove, r, f, y, x, cl); // allowed, generate
410 if(occup != 4) break; // not valid transit square
413 dx = dy = 1; dirSet = 0x99; // prepare for diagonal moves of K,Q
414 } while(retry--); // and start doing them
415 if(tx >= 0) break; // don't do other atoms in continuation legs
419 // [HGM] move generation now based on hierarchy of subroutines for rays and combinations of rays
422 SlideForward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
427 if (rt >= BOARD_HEIGHT) break;
428 if (SameColor(board[rf][ff], board[rt][ft])) break;
429 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
430 if (board[rt][ft] != EmptySquare) break;
435 SlideBackward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
441 if (SameColor(board[rf][ff], board[rt][ft])) break;
442 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
443 if (board[rt][ft] != EmptySquare) break;
448 SlideVertical (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
450 SlideForward(board, flags, rf, ff, callback, closure);
451 SlideBackward(board, flags, rf, ff, callback, closure);
455 SlideSideways (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
457 int i, s, rt = rf, ft;
458 for(s = -1; s <= 1; s+= 2) {
461 if (ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
462 if (SameColor(board[rf][ff], board[rt][ft])) break;
463 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
464 if (board[rt][ft] != EmptySquare) break;
470 SlideDiagForward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
473 for(s = -1; s <= 1; s+= 2) {
477 if (rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
478 if (SameColor(board[rf][ff], board[rt][ft])) break;
479 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
480 if (board[rt][ft] != EmptySquare) break;
486 SlideDiagBackward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
489 for(s = -1; s <= 1; s+= 2) {
493 if (rt < 0 || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
494 if (SameColor(board[rf][ff], board[rt][ft])) break;
495 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
496 if (board[rt][ft] != EmptySquare) break;
502 Rook (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
504 SlideVertical(board, flags, rf, ff, callback, closure);
505 SlideSideways(board, flags, rf, ff, callback, closure);
509 Bishop (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
511 SlideDiagForward(board, flags, rf, ff, callback, closure);
512 SlideDiagBackward(board, flags, rf, ff, callback, closure);
516 Sting (Board board, int flags, int rf, int ff, int dy, int dx, MoveCallback callback, VOIDSTAR closure)
517 { // Lion-like move of Horned Falcon and Souring Eagle
518 int ft = ff + dx, rt = rf + dy;
519 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) return;
521 if (!SameColor(board[rf][ff], board[rt][ft]))
522 callback(board, flags, board[rt][ft] != EmptySquare ? FirstLeg : NormalMove, rf, ff, rt, ft, closure);
525 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) return;
527 if (!SameColor(board[rf][ff], board[rt][ft]))
528 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
529 if (!SameColor(board[rf][ff], board[rf+dy][ff+dx]))
530 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
535 StepForward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
537 int ft = ff, rt = rf + 1;
538 if (rt >= BOARD_HEIGHT) return;
539 if (SameColor(board[rf][ff], board[rt][ft])) return;
540 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
544 StepBackward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
546 int ft = ff, rt = rf - 1;
548 if (SameColor(board[rf][ff], board[rt][ft])) return;
549 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
553 StepSideways (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
557 if (!(rt >= BOARD_HEIGHT || ft >= BOARD_RGHT) && !SameColor(board[rf][ff], board[rt][ft]))
558 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
560 if (!(rt >= BOARD_HEIGHT || ft < BOARD_LEFT) && !SameColor(board[rf][ff], board[rt][ft]))
561 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
565 StepDiagForward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
568 if (rt >= BOARD_HEIGHT) return;
570 if (!(rt >= BOARD_HEIGHT || ft >= BOARD_RGHT) && !SameColor(board[rf][ff], board[rt][ft]))
571 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
573 if (!(rt >= BOARD_HEIGHT || ft < BOARD_LEFT) && !SameColor(board[rf][ff], board[rt][ft]))
574 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
578 StepDiagBackward (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
583 if (!(rt < 0 || ft >= BOARD_RGHT) && !SameColor(board[rf][ff], board[rt][ft]))
584 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
586 if (!(rt < 0 || ft < BOARD_LEFT) && !SameColor(board[rf][ff], board[rt][ft]))
587 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
591 StepVertical (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
593 StepForward(board, flags, rf, ff, callback, closure);
594 StepBackward(board, flags, rf, ff, callback, closure);
598 Ferz (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
600 StepDiagForward(board, flags, rf, ff, callback, closure);
601 StepDiagBackward(board, flags, rf, ff, callback, closure);
605 Wazir (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
607 StepVertical(board, flags, rf, ff, callback, closure);
608 StepSideways(board, flags, rf, ff, callback, closure);
612 Knight (Board board, int flags, int rf, int ff, MoveCallback callback, VOIDSTAR closure)
615 for (i = -1; i <= 1; i += 2)
616 for (j = -1; j <= 1; j += 2)
617 for (s = 1; s <= 2; s++) {
620 if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
621 && ( gameInfo.variant != VariantXiangqi || board[rf+i*(s-1)][ff+j*(2-s)] == EmptySquare)
622 && !SameColor(board[rf][ff], board[rt][ft]))
623 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
627 /* Call callback once for each pseudo-legal move in the given
628 position, except castling moves. A move is pseudo-legal if it is
629 legal, or if it would be legal except that it leaves the king in
630 check. In the arguments, epfile is EP_NONE if the previous move
631 was not a double pawn push, or the file 0..7 if it was, or
632 EP_UNKNOWN if we don't know and want to allow all e.p. captures.
633 Promotion moves generated are to Queen only.
636 GenPseudoLegal (Board board, int flags, MoveCallback callback, VOIDSTAR closure, ChessSquare filter)
637 // speed: only do moves with this piece type
640 int i, j, d, s, fs, rs, rt, ft, m;
641 int epfile = (signed char)board[EP_STATUS]; // [HGM] gamestate: extract ep status from board
642 int promoRank = gameInfo.variant == VariantMakruk || gameInfo.variant == VariantGrand || gameInfo.variant == VariantChuChess ? 3 : 1;
644 for (rf = 0; rf < BOARD_HEIGHT; rf++)
645 for (ff = BOARD_LEFT; ff < BOARD_RGHT; ff++) {
648 if(board[rf][ff] == EmptySquare) continue;
649 if ((flags & F_WHITE_ON_MOVE) != (board[rf][ff] < BlackPawn)) continue; // [HGM] speed: wrong color
650 m = 0; piece = board[rf][ff];
651 if(PieceToChar(piece) == '~')
652 piece = (ChessSquare) ( DEMOTED piece );
653 if(filter != EmptySquare && piece != filter) continue;
654 if(pieceDefs && pieceDesc[piece]) { // [HGM] gen: use engine-defined moves
655 MovesFromString(board, flags, ff, rf, -1, -1, 0, pieceDesc[piece], callback, closure);
658 if(IS_SHOGI(gameInfo.variant))
659 piece = (ChessSquare) ( SHOGI piece );
661 switch ((int)piece) {
662 /* case EmptySquare: [HGM] this is nonsense, and conflicts with Shogi cases */
664 /* can't happen ([HGM] except for faries...) */
668 if(gameInfo.variant == VariantXiangqi) {
669 /* [HGM] capture and move straight ahead in Xiangqi */
670 if (rf < BOARD_HEIGHT-1 &&
671 !SameColor(board[rf][ff], board[rf + 1][ff]) ) {
672 callback(board, flags, NormalMove,
673 rf, ff, rf + 1, ff, closure);
675 /* and move sideways when across the river */
676 for (s = -1; s <= 1; s += 2) {
677 if (rf >= BOARD_HEIGHT>>1 &&
678 ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
679 !WhitePiece(board[rf][ff+s]) ) {
680 callback(board, flags, NormalMove,
681 rf, ff, rf, ff+s, closure);
686 if (rf < BOARD_HEIGHT-1 && board[rf + 1][ff] == EmptySquare) {
687 callback(board, flags,
688 rf >= BOARD_HEIGHT-1-promoRank ? WhitePromotion : NormalMove,
689 rf, ff, rf + 1, ff, closure);
691 if (rf <= (BOARD_HEIGHT>>1)-3 && board[rf+1][ff] == EmptySquare && // [HGM] grand: also on 3rd rank on 10-board
692 gameInfo.variant != VariantShatranj && /* [HGM] */
693 gameInfo.variant != VariantCourier && /* [HGM] */
694 board[rf+2][ff] == EmptySquare ) {
695 callback(board, flags, NormalMove,
696 rf, ff, rf+2, ff, closure);
698 for (s = -1; s <= 1; s += 2) {
699 if (rf < BOARD_HEIGHT-1 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
700 ((flags & F_KRIEGSPIEL_CAPTURE) ||
701 BlackPiece(board[rf + 1][ff + s]))) {
702 callback(board, flags,
703 rf >= BOARD_HEIGHT-1-promoRank ? WhitePromotion : NormalMove,
704 rf, ff, rf + 1, ff + s, closure);
706 if (rf >= BOARD_HEIGHT+1>>1) {// [HGM] grand: 4th & 5th rank on 10-board
707 if (ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
708 (epfile == ff + s || epfile == EP_UNKNOWN) && rf < BOARD_HEIGHT-3 &&
709 board[rf][ff + s] == BlackPawn &&
710 board[rf+1][ff + s] == EmptySquare) {
711 callback(board, flags, WhiteCapturesEnPassant,
712 rf, ff, rf+1, ff + s, closure);
719 if(gameInfo.variant == VariantXiangqi) {
720 /* [HGM] capture straight ahead in Xiangqi */
721 if (rf > 0 && !SameColor(board[rf][ff], board[rf - 1][ff]) ) {
722 callback(board, flags, NormalMove,
723 rf, ff, rf - 1, ff, closure);
725 /* and move sideways when across the river */
726 for (s = -1; s <= 1; s += 2) {
727 if (rf < BOARD_HEIGHT>>1 &&
728 ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
729 !BlackPiece(board[rf][ff+s]) ) {
730 callback(board, flags, NormalMove,
731 rf, ff, rf, ff+s, closure);
736 if (rf > 0 && board[rf - 1][ff] == EmptySquare) {
737 callback(board, flags,
738 rf <= promoRank ? BlackPromotion : NormalMove,
739 rf, ff, rf - 1, ff, closure);
741 if (rf >= (BOARD_HEIGHT+1>>1)+2 && board[rf-1][ff] == EmptySquare && // [HGM] grand
742 gameInfo.variant != VariantShatranj && /* [HGM] */
743 gameInfo.variant != VariantCourier && /* [HGM] */
744 board[rf-2][ff] == EmptySquare) {
745 callback(board, flags, NormalMove,
746 rf, ff, rf-2, ff, closure);
748 for (s = -1; s <= 1; s += 2) {
749 if (rf > 0 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
750 ((flags & F_KRIEGSPIEL_CAPTURE) ||
751 WhitePiece(board[rf - 1][ff + s]))) {
752 callback(board, flags,
753 rf <= promoRank ? BlackPromotion : NormalMove,
754 rf, ff, rf - 1, ff + s, closure);
756 if (rf < BOARD_HEIGHT>>1) {
757 if (ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
758 (epfile == ff + s || epfile == EP_UNKNOWN) && rf > 2 &&
759 board[rf][ff + s] == WhitePawn &&
760 board[rf-1][ff + s] == EmptySquare) {
761 callback(board, flags, BlackCapturesEnPassant,
762 rf, ff, rf-1, ff + s, closure);
772 for (i = -1; i <= 1; i += 2)
773 for (j = -1; j <= 1; j += 2)
774 for (s = 1; s <= 2; s++) {
777 if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
778 && ( gameInfo.variant != VariantXiangqi || board[rf+i*(s-1)][ff+j*(2-s)] == EmptySquare)
779 && !SameColor(board[rf][ff], board[rt][ft]))
780 callback(board, flags, NormalMove,
781 rf, ff, rt, ft, closure);
785 case SHOGI WhiteKnight:
786 for (s = -1; s <= 1; s += 2) {
787 if (rf < BOARD_HEIGHT-2 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
788 !SameColor(board[rf][ff], board[rf + 2][ff + s])) {
789 callback(board, flags, NormalMove,
790 rf, ff, rf + 2, ff + s, closure);
795 case SHOGI BlackKnight:
796 for (s = -1; s <= 1; s += 2) {
797 if (rf > 1 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT &&
798 !SameColor(board[rf][ff], board[rf - 2][ff + s])) {
799 callback(board, flags, NormalMove,
800 rf, ff, rf - 2, ff + s, closure);
807 for (d = 0; d <= 1; d++)
808 for (s = -1; s <= 1; s += 2) {
811 rt = rf + (i * s) * d;
812 ft = ff + (i * s) * (1 - d);
813 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
814 if (m == 0 && board[rt][ft] == EmptySquare)
815 callback(board, flags, NormalMove,
816 rf, ff, rt, ft, closure);
817 if (m == 1 && board[rt][ft] != EmptySquare &&
818 !SameColor(board[rf][ff], board[rt][ft]) )
819 callback(board, flags, NormalMove,
820 rf, ff, rt, ft, closure);
821 if (board[rt][ft] != EmptySquare && m++) break;
826 /* Gold General (and all its promoted versions) . First do the */
827 /* diagonal forward steps, then proceed as normal Wazir */
828 case SHOGI (PROMOTED WhitePawn):
829 if(gameInfo.variant == VariantShogi) goto WhiteGold;
830 case SHOGI (PROMOTED BlackPawn):
831 if(gameInfo.variant == VariantShogi) goto BlackGold;
832 SlideVertical(board, flags, rf, ff, callback, closure);
835 case SHOGI (PROMOTED WhiteKnight):
836 if(gameInfo.variant == VariantShogi) goto WhiteGold;
837 case SHOGI BlackDrunk:
838 case SHOGI BlackAlfil:
839 Ferz(board, flags, rf, ff, callback, closure);
840 StepSideways(board, flags, rf, ff, callback, closure);
841 StepBackward(board, flags, rf, ff, callback, closure);
844 case SHOGI (PROMOTED BlackKnight):
845 if(gameInfo.variant == VariantShogi) goto BlackGold;
846 case SHOGI WhiteDrunk:
847 case SHOGI WhiteAlfil:
848 Ferz(board, flags, rf, ff, callback, closure);
849 StepSideways(board, flags, rf, ff, callback, closure);
850 StepForward(board, flags, rf, ff, callback, closure);
854 case SHOGI WhiteStag:
855 case SHOGI BlackStag:
856 if(gameInfo.variant == VariantShogi) goto BlackGold;
857 SlideVertical(board, flags, rf, ff, callback, closure);
858 Ferz(board, flags, rf, ff, callback, closure);
859 StepSideways(board, flags, rf, ff, callback, closure);
862 case SHOGI (PROMOTED WhiteQueen):
863 case SHOGI WhiteTokin:
864 case SHOGI WhiteWazir:
866 StepDiagForward(board, flags, rf, ff, callback, closure);
867 Wazir(board, flags, rf, ff, callback, closure);
870 case SHOGI (PROMOTED BlackQueen):
871 case SHOGI BlackTokin:
872 case SHOGI BlackWazir:
874 StepDiagBackward(board, flags, rf, ff, callback, closure);
875 Wazir(board, flags, rf, ff, callback, closure);
880 Wazir(board, flags, rf, ff, callback, closure);
883 case SHOGI WhiteMarshall:
884 case SHOGI BlackMarshall:
885 Ferz(board, flags, rf, ff, callback, closure);
886 for (d = 0; d <= 1; d++)
887 for (s = -2; s <= 2; s += 4) {
889 ft = ff + s * (1 - d);
890 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) continue;
891 if (!SameColor(board[rf][ff], board[rt][ft]) )
892 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
896 case SHOGI WhiteAngel:
897 case SHOGI BlackAngel:
898 Wazir(board, flags, rf, ff, callback, closure);
902 /* [HGM] support Shatranj pieces */
903 for (rs = -1; rs <= 1; rs += 2)
904 for (fs = -1; fs <= 1; fs += 2) {
907 if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
908 && ( gameInfo.variant != VariantXiangqi ||
909 board[rf+rs][ff+fs] == EmptySquare && (2*rf < BOARD_HEIGHT) == (2*rt < BOARD_HEIGHT) )
911 && !SameColor(board[rf][ff], board[rt][ft]))
912 callback(board, flags, NormalMove,
913 rf, ff, rt, ft, closure);
914 if(gameInfo.variant == VariantShatranj || gameInfo.variant == VariantCourier ||
915 gameInfo.variant == VariantChu || gameInfo.variant == VariantXiangqi) continue; // classical Alfil
916 rt = rf + rs; // in unknown variant we assume Modern Elephant, which can also do one step
918 if (!(rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT)
919 && !SameColor(board[rf][ff], board[rt][ft]))
920 callback(board, flags, NormalMove,
921 rf, ff, rt, ft, closure);
923 if(gameInfo.variant == VariantSpartan)
924 for(fs = -1; fs <= 1; fs += 2) {
926 if (!(ft < BOARD_LEFT || ft >= BOARD_RGHT) && board[rf][ft] == EmptySquare)
927 callback(board, flags, NormalMove, rf, ff, rf, ft, closure);
931 /* Make Dragon-Horse also do Dababba moves outside Shogi, for better disambiguation in variant Fairy */
934 if(gameInfo.variant == VariantChuChess) goto DragonHorse;
935 for (d = 0; d <= 1; d++) // Dababba moves that Rook cannot do
936 for (s = -2; s <= 2; s += 4) {
938 ft = ff + s * (1 - d);
939 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) continue;
940 if (SameColor(board[rf][ff], board[rt][ft])) continue;
941 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
944 /* Shogi Dragon Horse has to continue with Wazir after Bishop */
945 case SHOGI WhiteCardinal:
946 case SHOGI BlackCardinal:
947 case SHOGI WhitePCardinal:
948 case SHOGI BlackPCardinal:
950 Bishop(board, flags, rf, ff, callback, closure);
951 Wazir(board, flags, rf, ff, callback, closure);
954 /* Capablanca Archbishop continues as Knight */
957 Knight(board, flags, rf, ff, callback, closure);
959 /* Shogi Bishops are ordinary Bishops */
960 case SHOGI WhiteBishop:
961 case SHOGI BlackBishop:
962 case SHOGI WhitePBishop:
963 case SHOGI BlackPBishop:
966 Bishop(board, flags, rf, ff, callback, closure);
969 /* Shogi Lance is unlike anything, and asymmetric at that */
970 case SHOGI WhiteQueen:
971 if(gameInfo.variant == VariantChu) goto doQueen;
975 if (rt >= BOARD_HEIGHT) break;
976 if (SameColor(board[rf][ff], board[rt][ft])) break;
977 callback(board, flags, NormalMove,
978 rf, ff, rt, ft, closure);
979 if (board[rt][ft] != EmptySquare) break;
983 case SHOGI BlackQueen:
984 if(gameInfo.variant == VariantChu) goto doQueen;
989 if (SameColor(board[rf][ff], board[rt][ft])) break;
990 callback(board, flags, NormalMove,
991 rf, ff, rt, ft, closure);
992 if (board[rt][ft] != EmptySquare) break;
996 /* Make Dragon-King Dababba & Rook-like outside Shogi, for better disambiguation in variant Fairy */
999 if(gameInfo.variant == VariantChuChess) goto DragonKing;
1000 for (d = 0; d <= 1; d++) // Dababba moves that Rook cannot do
1001 for (s = -2; s <= 2; s += 4) {
1003 ft = ff + s * (1 - d);
1004 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) continue;
1005 if (board[rf+rt>>1][ff+ft>>1] == EmptySquare && gameInfo.variant != VariantSpartan) continue;
1006 if (SameColor(board[rf][ff], board[rt][ft])) continue;
1007 callback(board, flags, NormalMove, rf, ff, rt, ft, closure);
1009 if(gameInfo.variant == VariantSpartan) // in Spartan Chess restrict range to modern Dababba
1010 Wazir(board, flags, rf, ff, callback, closure);
1012 Rook(board, flags, rf, ff, callback, closure);
1015 /* Shogi Dragon King has to continue as Ferz after Rook moves */
1016 case SHOGI WhiteDragon:
1017 case SHOGI BlackDragon:
1018 case SHOGI WhitePDragon:
1019 case SHOGI BlackPDragon:
1021 Rook(board, flags, rf, ff, callback, closure);
1022 Ferz(board, flags, rf, ff, callback, closure);
1026 /* Capablanca Chancellor sets flag to continue as Knight */
1029 Rook(board, flags, rf, ff, callback, closure);
1030 if(gameInfo.variant == VariantSpartan) // in Spartan Chess Chancellor is used for Dragon King.
1031 Ferz(board, flags, rf, ff, callback, closure);
1033 Knight(board, flags, rf, ff, callback, closure);
1036 /* Shogi Rooks are ordinary Rooks */
1037 case SHOGI WhiteRook:
1038 case SHOGI BlackRook:
1039 case SHOGI WhitePRook:
1040 case SHOGI BlackPRook:
1043 Rook(board, flags, rf, ff, callback, closure);
1048 case SHOGI WhiteMother:
1049 case SHOGI BlackMother:
1051 Rook(board, flags, rf, ff, callback, closure);
1052 Bishop(board, flags, rf, ff, callback, closure);
1055 case SHOGI WhitePawn:
1056 StepForward(board, flags, rf, ff, callback, closure);
1059 case SHOGI BlackPawn:
1060 StepBackward(board, flags, rf, ff, callback, closure);
1064 if(gameInfo.variant != VariantMakruk && gameInfo.variant != VariantASEAN) goto commoner;
1065 case SHOGI WhiteFerz:
1066 Ferz(board, flags, rf, ff, callback, closure);
1067 StepForward(board, flags, rf, ff, callback, closure);
1071 if(gameInfo.variant != VariantMakruk && gameInfo.variant != VariantASEAN) goto commoner;
1072 case SHOGI BlackFerz:
1073 StepBackward(board, flags, rf, ff, callback, closure);
1077 /* [HGM] support Shatranj pieces */
1078 Ferz(board, flags, rf, ff, callback, closure);
1083 Knight(board, flags, rf, ff, callback, closure); // [HGM] superchess: use for Centaur
1086 case SHOGI WhiteMonarch:
1087 case SHOGI BlackMonarch:
1088 case SHOGI WhiteKing:
1089 case SHOGI BlackKing:
1092 Ferz(board, flags, rf, ff, callback, closure);
1093 Wazir(board, flags, rf, ff, callback, closure);
1096 case WhiteNightrider:
1097 case BlackNightrider:
1098 for (i = -1; i <= 1; i += 2)
1099 for (j = -1; j <= 1; j += 2)
1100 for (s = 1; s <= 2; s++) { int k;
1103 ft = ff + k*j*(3-s);
1104 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) break;
1105 if (SameColor(board[rf][ff], board[rt][ft])) break;
1106 callback(board, flags, NormalMove,
1107 rf, ff, rt, ft, closure);
1108 if (board[rt][ft] != EmptySquare) break;
1114 Bishop(board, flags, rf, ff, callback, closure);
1115 Rook(board, flags, rf, ff, callback, closure);
1116 Knight(board, flags, rf, ff, callback, closure);
1119 // Use Lance as Berolina / Spartan Pawn.
1121 if(gameInfo.variant == VariantSuper) goto Amazon;
1122 if (rf < BOARD_HEIGHT-1 && BlackPiece(board[rf + 1][ff]))
1123 callback(board, flags,
1124 rf >= BOARD_HEIGHT-1-promoRank ? WhitePromotion : NormalMove,
1125 rf, ff, rf + 1, ff, closure);
1126 for (s = -1; s <= 1; s += 2) {
1127 if (rf < BOARD_HEIGHT-1 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT && board[rf + 1][ff + s] == EmptySquare)
1128 callback(board, flags,
1129 rf >= BOARD_HEIGHT-1-promoRank ? WhitePromotion : NormalMove,
1130 rf, ff, rf + 1, ff + s, closure);
1131 if (rf == 1 && ff + 2*s >= BOARD_LEFT && ff + 2*s < BOARD_RGHT && board[3][ff + 2*s] == EmptySquare )
1132 callback(board, flags, NormalMove, rf, ff, 3, ff + 2*s, closure);
1137 if(gameInfo.variant == VariantSuper) goto Amazon;
1138 if (rf > 0 && WhitePiece(board[rf - 1][ff]))
1139 callback(board, flags,
1140 rf <= promoRank ? BlackPromotion : NormalMove,
1141 rf, ff, rf - 1, ff, closure);
1142 for (s = -1; s <= 1; s += 2) {
1143 if (rf > 0 && ff + s >= BOARD_LEFT && ff + s < BOARD_RGHT && board[rf - 1][ff + s] == EmptySquare)
1144 callback(board, flags,
1145 rf <= promoRank ? BlackPromotion : NormalMove,
1146 rf, ff, rf - 1, ff + s, closure);
1147 if (rf == BOARD_HEIGHT-2 && ff + 2*s >= BOARD_LEFT && ff + 2*s < BOARD_RGHT && board[rf-2][ff + 2*s] == EmptySquare )
1148 callback(board, flags, NormalMove, rf, ff, rf-2, ff + 2*s, closure);
1152 case SHOGI WhiteNothing:
1153 case SHOGI BlackNothing:
1154 case SHOGI WhiteLion:
1155 case SHOGI BlackLion:
1158 for(rt = rf - 2; rt <= rf + 2; rt++) for(ft = ff - 2; ft <= ff + 2; ft++) {
1159 if (rt < 0 || rt >= BOARD_HEIGHT || ft < BOARD_LEFT || ft >= BOARD_RGHT) continue;
1160 if (!(ff == ft && rf == rt) && SameColor(board[rf][ff], board[rt][ft])) continue;
1161 i = (killX >= 0 && (rt-killY)*(rt-killY) + (killX-ft)*(killX-ft) < 3); legNr += 2*i;
1162 callback(board, flags, (rt-rf)*(rt-rf) + (ff-ft)*(ff-ft) < 3 && board[rt][ft] != EmptySquare ? FirstLeg : NormalMove,
1163 rf, ff, rt, ft, closure);
1168 case SHOGI WhiteFalcon:
1169 case SHOGI BlackFalcon:
1170 case SHOGI WhitePDagger:
1171 case SHOGI BlackPDagger:
1172 SlideSideways(board, flags, rf, ff, callback, closure);
1173 StepVertical(board, flags, rf, ff, callback, closure);
1176 case SHOGI WhiteCobra:
1177 case SHOGI BlackCobra:
1178 StepVertical(board, flags, rf, ff, callback, closure);
1181 case SHOGI (PROMOTED WhiteFerz):
1182 if(gameInfo.variant == VariantShogi) goto WhiteGold;
1183 case SHOGI (PROMOTED BlackFerz):
1184 if(gameInfo.variant == VariantShogi) goto BlackGold;
1185 case SHOGI WhitePSword:
1186 case SHOGI BlackPSword:
1187 SlideVertical(board, flags, rf, ff, callback, closure);
1188 StepSideways(board, flags, rf, ff, callback, closure);
1191 case SHOGI WhiteUnicorn:
1192 case SHOGI BlackUnicorn:
1193 Ferz(board, flags, rf, ff, callback, closure);
1194 StepVertical(board, flags, rf, ff, callback, closure);
1197 case SHOGI WhiteMan:
1198 StepDiagForward(board, flags, rf, ff, callback, closure);
1199 StepVertical(board, flags, rf, ff, callback, closure);
1202 case SHOGI BlackMan:
1203 StepDiagBackward(board, flags, rf, ff, callback, closure);
1204 StepVertical(board, flags, rf, ff, callback, closure);
1207 case SHOGI WhiteHCrown:
1208 case SHOGI BlackHCrown:
1209 Bishop(board, flags, rf, ff, callback, closure);
1210 SlideSideways(board, flags, rf, ff, callback, closure);
1213 case SHOGI WhiteCrown:
1214 case SHOGI BlackCrown:
1215 Bishop(board, flags, rf, ff, callback, closure);
1216 SlideVertical(board, flags, rf, ff, callback, closure);
1219 case SHOGI WhiteHorned:
1220 Sting(board, flags, rf, ff, 1, 0, callback, closure);
1221 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1222 if(killX >= 0) break;
1223 Bishop(board, flags, rf, ff, callback, closure);
1224 SlideSideways(board, flags, rf, ff, callback, closure);
1225 SlideBackward(board, flags, rf, ff, callback, closure);
1228 case SHOGI BlackHorned:
1229 Sting(board, flags, rf, ff, -1, 0, callback, closure);
1230 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1231 if(killX >= 0) break;
1232 Bishop(board, flags, rf, ff, callback, closure);
1233 SlideSideways(board, flags, rf, ff, callback, closure);
1234 SlideForward(board, flags, rf, ff, callback, closure);
1237 case SHOGI WhiteEagle:
1238 Sting(board, flags, rf, ff, 1, 1, callback, closure);
1239 Sting(board, flags, rf, ff, 1, -1, callback, closure);
1240 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1241 if(killX >= 0) break;
1242 Rook(board, flags, rf, ff, callback, closure);
1243 SlideDiagBackward(board, flags, rf, ff, callback, closure);
1246 case SHOGI BlackEagle:
1247 Sting(board, flags, rf, ff, -1, 1, callback, closure);
1248 Sting(board, flags, rf, ff, -1, -1, callback, closure);
1249 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1250 if(killX >= 0) break;
1251 Rook(board, flags, rf, ff, callback, closure);
1252 SlideDiagForward(board, flags, rf, ff, callback, closure);
1255 case SHOGI WhiteDolphin:
1256 case SHOGI BlackHorse:
1257 SlideDiagBackward(board, flags, rf, ff, callback, closure);
1258 SlideVertical(board, flags, rf, ff, callback, closure);
1261 case SHOGI BlackDolphin:
1262 case SHOGI WhiteHorse:
1263 SlideDiagForward(board, flags, rf, ff, callback, closure);
1264 SlideVertical(board, flags, rf, ff, callback, closure);
1267 case SHOGI WhiteLance:
1268 SlideForward(board, flags, rf, ff, callback, closure);
1271 case SHOGI BlackLance:
1272 SlideBackward(board, flags, rf, ff, callback, closure);
1275 case WhiteFalcon: // [HGM] wild: for wildcards, self-capture symbolizes move to anywhere
1279 callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
1292 int rFilter, fFilter; // [HGM] speed: sorry, but I get a bit tired of this closure madness
1293 Board xqCheckers, nullBoard;
1295 extern void GenLegalCallback P((Board board, int flags, ChessMove kind,
1296 int rf, int ff, int rt, int ft,
1300 GenLegalCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1302 register GenLegalClosure *cl = (GenLegalClosure *) closure;
1304 if(rFilter >= 0 && rFilter != rt || fFilter >= 0 && fFilter != ft) return; // [HGM] speed: ignore moves with wrong to-square
1306 if (board[EP_STATUS] == EP_IRON_LION && (board[rt][ft] == WhiteLion || board[rt][ft] == BlackLion)) return; //[HGM] lion
1308 if (!(flags & F_IGNORE_CHECK) ) {
1309 int check, promo = (gameInfo.variant == VariantSpartan && kind == BlackPromotion);
1312 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++)
1313 kings += (board[r][f] == BlackKing);
1317 board[rf][ff] = BlackKing; // [HGM] spartan: promote to King before check-test
1319 check = CheckTest(board, flags, rf, ff, rt, ft,
1320 kind == WhiteCapturesEnPassant ||
1321 kind == BlackCapturesEnPassant);
1322 if(promo) board[rf][ff] = BlackLance;
1325 if (flags & F_ATOMIC_CAPTURE) {
1326 if (board[rt][ft] != EmptySquare ||
1327 kind == WhiteCapturesEnPassant || kind == BlackCapturesEnPassant) {
1329 ChessSquare king = (flags & F_WHITE_ON_MOVE) ? WhiteKing : BlackKing;
1330 if (board[rf][ff] == king) return;
1331 for (r = rt-1; r <= rt+1; r++) {
1332 for (f = ft-1; f <= ft+1; f++) {
1333 if (r >= 0 && r < BOARD_HEIGHT && f >= BOARD_LEFT && f < BOARD_RGHT &&
1334 board[r][f] == king) return;
1339 cl->cb(board, flags, kind, rf, ff, rt, ft, cl->cl);
1346 int captures; // [HGM] losers
1347 } LegalityTestClosure;
1350 /* Like GenPseudoLegal, but (1) include castling moves, (2) unless
1351 F_IGNORE_CHECK is set in the flags, omit moves that would leave the
1352 king in check, and (3) if F_ATOMIC_CAPTURE is set in the flags, omit
1353 moves that would destroy your own king. The CASTLE_OK flags are
1354 true if castling is not yet ruled out by a move of the king or
1355 rook. Return TRUE if the player on move is currently in check and
1356 F_IGNORE_CHECK is not set. [HGM] add castlingRights parameter */
1358 GenLegal (Board board, int flags, MoveCallback callback, VOIDSTAR closure, ChessSquare filter)
1361 int ff, ft, k, left, right, swap;
1362 int ignoreCheck = (flags & F_IGNORE_CHECK) != 0;
1363 ChessSquare wKing = WhiteKing, bKing = BlackKing, *castlingRights = board[CASTLING];
1364 int inCheck = !ignoreCheck && CheckTest(board, flags, -1, -1, -1, -1, FALSE); // kludge alert: this would mark pre-existing checkers if status==1
1369 xqCheckers[EP_STATUS] *= 2; // quasi: if previous CheckTest has been marking, we now set flag for suspending same checkers
1370 if(filter == EmptySquare) rFilter = fFilter = -1; // [HGM] speed: do not filter on square if we do not filter on piece
1371 GenPseudoLegal(board, flags, GenLegalCallback, (VOIDSTAR) &cl, filter);
1373 if (inCheck) return TRUE;
1375 /* Generate castling moves */
1376 if(gameInfo.variant == VariantKnightmate) { /* [HGM] Knightmate */
1377 wKing = WhiteUnicorn; bKing = BlackUnicorn;
1380 p = (flags & F_WHITE_ON_MOVE ? pieceDesc[wKing] : pieceDesc[bKing]);
1381 if(p && strchr(p, 'O')) return FALSE; // [HGM] gen: castlings were already generated from string
1383 for (ff = BOARD_WIDTH>>1; ff >= (BOARD_WIDTH-1)>>1; ff-- /*ics wild 1*/) {
1384 if ((flags & F_WHITE_ON_MOVE) &&
1385 (flags & F_WHITE_KCASTLE_OK) &&
1386 board[0][ff] == wKing &&
1387 board[0][ff + 1] == EmptySquare &&
1388 board[0][ff + 2] == EmptySquare &&
1389 board[0][BOARD_RGHT-3] == EmptySquare &&
1390 board[0][BOARD_RGHT-2] == EmptySquare &&
1391 board[0][BOARD_RGHT-1] == WhiteRook &&
1392 castlingRights[0] != NoRights && /* [HGM] check rights */
1393 ( castlingRights[2] == ff || castlingRights[6] == ff ) &&
1395 (!CheckTest(board, flags, 0, ff, 0, ff + 1, FALSE) &&
1396 !CheckTest(board, flags, 0, ff, 0, BOARD_RGHT-3, FALSE) &&
1397 (gameInfo.variant != VariantJanus || !CheckTest(board, flags, 0, ff, 0, BOARD_RGHT-2, FALSE)) &&
1398 !CheckTest(board, flags, 0, ff, 0, ff + 2, FALSE)))) {
1400 callback(board, flags,
1401 ff==BOARD_WIDTH>>1 ? WhiteKingSideCastle : WhiteKingSideCastleWild,
1402 0, ff, 0, ff + ((gameInfo.boardWidth+2)>>2) + (gameInfo.variant == VariantJanus), closure);
1404 if ((flags & F_WHITE_ON_MOVE) &&
1405 (flags & F_WHITE_QCASTLE_OK) &&
1406 board[0][ff] == wKing &&
1407 board[0][ff - 1] == EmptySquare &&
1408 board[0][ff - 2] == EmptySquare &&
1409 board[0][BOARD_LEFT+2] == EmptySquare &&
1410 board[0][BOARD_LEFT+1] == EmptySquare &&
1411 board[0][BOARD_LEFT+0] == WhiteRook &&
1412 castlingRights[1] != NoRights && /* [HGM] check rights */
1413 ( castlingRights[2] == ff || castlingRights[6] == ff ) &&
1415 (!CheckTest(board, flags, 0, ff, 0, ff - 1, FALSE) &&
1416 !CheckTest(board, flags, 0, ff, 0, BOARD_LEFT+3, FALSE) &&
1417 !CheckTest(board, flags, 0, ff, 0, ff - 2, FALSE)))) {
1419 callback(board, flags,
1420 ff==BOARD_WIDTH>>1 ? WhiteQueenSideCastle : WhiteQueenSideCastleWild,
1421 0, ff, 0, ff - ((gameInfo.boardWidth+2)>>2), closure);
1423 if (!(flags & F_WHITE_ON_MOVE) &&
1424 (flags & F_BLACK_KCASTLE_OK) &&
1425 board[BOARD_HEIGHT-1][ff] == bKing &&
1426 board[BOARD_HEIGHT-1][ff + 1] == EmptySquare &&
1427 board[BOARD_HEIGHT-1][ff + 2] == EmptySquare &&
1428 board[BOARD_HEIGHT-1][BOARD_RGHT-3] == EmptySquare &&
1429 board[BOARD_HEIGHT-1][BOARD_RGHT-2] == EmptySquare &&
1430 board[BOARD_HEIGHT-1][BOARD_RGHT-1] == BlackRook &&
1431 castlingRights[3] != NoRights && /* [HGM] check rights */
1432 ( castlingRights[5] == ff || castlingRights[7] == ff ) &&
1434 (!CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff + 1, FALSE) &&
1435 !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, BOARD_RGHT-3, FALSE) &&
1436 (gameInfo.variant != VariantJanus || !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, BOARD_RGHT-2, FALSE)) &&
1437 !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff + 2, FALSE)))) {
1439 callback(board, flags,
1440 ff==BOARD_WIDTH>>1 ? BlackKingSideCastle : BlackKingSideCastleWild,
1441 BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff + ((gameInfo.boardWidth+2)>>2) + (gameInfo.variant == VariantJanus), closure);
1443 if (!(flags & F_WHITE_ON_MOVE) &&
1444 (flags & F_BLACK_QCASTLE_OK) &&
1445 board[BOARD_HEIGHT-1][ff] == bKing &&
1446 board[BOARD_HEIGHT-1][ff - 1] == EmptySquare &&
1447 board[BOARD_HEIGHT-1][ff - 2] == EmptySquare &&
1448 board[BOARD_HEIGHT-1][BOARD_LEFT+2] == EmptySquare &&
1449 board[BOARD_HEIGHT-1][BOARD_LEFT+1] == EmptySquare &&
1450 board[BOARD_HEIGHT-1][BOARD_LEFT+0] == BlackRook &&
1451 castlingRights[4] != NoRights && /* [HGM] check rights */
1452 ( castlingRights[5] == ff || castlingRights[7] == ff ) &&
1454 (!CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff - 1, FALSE) &&
1455 !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, BOARD_LEFT+3, FALSE) &&
1456 !CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff - 2, FALSE)))) {
1458 callback(board, flags,
1459 ff==BOARD_WIDTH>>1 ? BlackQueenSideCastle : BlackQueenSideCastleWild,
1460 BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ff - ((gameInfo.boardWidth+2)>>2), closure);
1464 if((swap = gameInfo.variant == VariantSChess) || flags & F_FRC_TYPE_CASTLING) {
1466 /* generate all potential FRC castling moves (KxR), ignoring flags */
1467 /* [HGM] test if the Rooks we find have castling rights */
1468 /* In S-Chess we generate RxK for allowed castlings, for gating at Rook square */
1471 if ((flags & F_WHITE_ON_MOVE) != 0) {
1472 ff = castlingRights[2]; /* King file if we have any rights */
1473 if(ff != NoRights && board[0][ff] == WhiteKing) {
1474 if (appData.debugMode) {
1475 fprintf(debugFP, "FRC castling, %d %d %d %d %d %d\n",
1476 castlingRights[0],castlingRights[1],ff,castlingRights[3],castlingRights[4],castlingRights[5]);
1478 ft = castlingRights[0]; /* Rook file if we have H-side rights */
1480 right = BOARD_RGHT-2;
1481 if(ff == BOARD_RGHT-2) left = right = ff-1; /* special case */
1482 for(k=left; k<=right && ft != NoRights; k++) /* first test if blocked */
1483 if(k != ft && board[0][k] != EmptySquare) ft = NoRights;
1484 for(k=left; k<right && ft != NoRights; k++) /* then if not checked */
1485 if(!ignoreCheck && CheckTest(board, flags, 0, ff, 0, k, FALSE)) ft = NoRights;
1486 if(ft != NoRights && board[0][ft] == WhiteRook) {
1487 if(flags & F_FRC_TYPE_CASTLING) callback(board, flags, WhiteHSideCastleFR, 0, ff, 0, ft, closure);
1488 if(swap) callback(board, flags, WhiteHSideCastleFR, 0, ft, 0, ff, closure);
1491 ft = castlingRights[1]; /* Rook file if we have A-side rights */
1492 left = BOARD_LEFT+2;
1494 if(ff <= BOARD_LEFT+2) { left = ff+1; right = BOARD_LEFT+3; }
1495 for(k=left; k<=right && ft != NoRights; k++) /* first test if blocked */
1496 if(k != ft && board[0][k] != EmptySquare) ft = NoRights;
1497 if(ft == 0 && ff != 1 && board[0][1] != EmptySquare) ft = NoRights; /* Rook can be blocked on b1 */
1498 if(ff > BOARD_LEFT+2)
1499 for(k=left+1; k<=right && ft != NoRights; k++) /* then if not checked */
1500 if(!ignoreCheck && CheckTest(board, flags, 0, ff, 0, k, FALSE)) ft = NoRights;
1501 if(ft != NoRights && board[0][ft] == WhiteRook) {
1502 if(flags & F_FRC_TYPE_CASTLING) callback(board, flags, WhiteASideCastleFR, 0, ff, 0, ft, closure);
1503 if(swap) callback(board, flags, WhiteASideCastleFR, 0, ft, 0, ff, closure);
1507 ff = castlingRights[5]; /* King file if we have any rights */
1508 if(ff != NoRights && board[BOARD_HEIGHT-1][ff] == BlackKing) {
1509 ft = castlingRights[3]; /* Rook file if we have H-side rights */
1511 right = BOARD_RGHT-2;
1512 if(ff == BOARD_RGHT-2) left = right = ff-1; /* special case */
1513 for(k=left; k<=right && ft != NoRights; k++) /* first test if blocked */
1514 if(k != ft && board[BOARD_HEIGHT-1][k] != EmptySquare) ft = NoRights;
1515 for(k=left; k<right && ft != NoRights; k++) /* then if not checked */
1516 if(!ignoreCheck && CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, k, FALSE)) ft = NoRights;
1517 if(ft != NoRights && board[BOARD_HEIGHT-1][ft] == BlackRook) {
1518 if(flags & F_FRC_TYPE_CASTLING) callback(board, flags, BlackHSideCastleFR, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ft, closure);
1519 if(swap) callback(board, flags, BlackHSideCastleFR, BOARD_HEIGHT-1, ft, BOARD_HEIGHT-1, ff, closure);
1522 ft = castlingRights[4]; /* Rook file if we have A-side rights */
1523 left = BOARD_LEFT+2;
1525 if(ff <= BOARD_LEFT+2) { left = ff+1; right = BOARD_LEFT+3; }
1526 for(k=left; k<=right && ft != NoRights; k++) /* first test if blocked */
1527 if(k != ft && board[BOARD_HEIGHT-1][k] != EmptySquare) ft = NoRights;
1528 if(ft == 0 && ff != 1 && board[BOARD_HEIGHT-1][1] != EmptySquare) ft = NoRights; /* Rook can be blocked on b8 */
1529 if(ff > BOARD_LEFT+2)
1530 for(k=left+1; k<=right && ft != NoRights; k++) /* then if not checked */
1531 if(!ignoreCheck && CheckTest(board, flags, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, k, FALSE)) ft = NoRights;
1532 if(ft != NoRights && board[BOARD_HEIGHT-1][ft] == BlackRook) {
1533 if(flags & F_FRC_TYPE_CASTLING) callback(board, flags, BlackASideCastleFR, BOARD_HEIGHT-1, ff, BOARD_HEIGHT-1, ft, closure);
1534 if(swap) callback(board, flags, BlackASideCastleFR, BOARD_HEIGHT-1, ft, BOARD_HEIGHT-1, ff, closure);
1551 extern void CheckTestCallback P((Board board, int flags, ChessMove kind,
1552 int rf, int ff, int rt, int ft,
1557 CheckTestCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1559 register CheckTestClosure *cl = (CheckTestClosure *) closure;
1561 if (rt == cl->rking && ft == cl->fking) {
1562 if(xqCheckers[EP_STATUS] >= 2 && xqCheckers[rf][ff]) return; // checker is piece with suspended checking power
1564 xqCheckers[rf][ff] = xqCheckers[EP_STATUS] & 1; // remember who is checking (if status == 1)
1566 if( board[EP_STATUS] == EP_ROYAL_LION && (board[rt][ft] == WhiteLion || board[rt][ft] == BlackLion)
1567 && (gameInfo.variant != VariantLion || board[rf][ff] != WhiteKing && board[rf][ff] != BlackKing) )
1568 cl->check++; // [HGM] lion: forbidden counterstrike against Lion equated to putting yourself in check
1572 /* If the player on move were to move from (rf, ff) to (rt, ft), would
1573 he leave himself in check? Or if rf == -1, is the player on move
1574 in check now? enPassant must be TRUE if the indicated move is an
1575 e.p. capture. The possibility of castling out of a check along the
1576 back rank is not accounted for (i.e., we still return nonzero), as
1577 this is illegal anyway. Return value is the number of times the
1578 king is in check. */
1580 CheckTest (Board board, int flags, int rf, int ff, int rt, int ft, int enPassant)
1582 CheckTestClosure cl;
1583 ChessSquare king = flags & F_WHITE_ON_MOVE ? WhiteKing : BlackKing;
1584 ChessSquare captured = EmptySquare, ep=0, trampled=0;
1585 /* Suppress warnings on uninitialized variables */
1587 if(gameInfo.variant == VariantXiangqi)
1588 king = flags & F_WHITE_ON_MOVE ? WhiteWazir : BlackWazir;
1589 if(gameInfo.variant == VariantKnightmate)
1590 king = flags & F_WHITE_ON_MOVE ? WhiteUnicorn : BlackUnicorn;
1591 if(gameInfo.variant == VariantChu) { // strictly speaking this is not needed, as Chu officially has no check
1592 int r, f, k = king, royals=0, prince = flags & F_WHITE_ON_MOVE ? WhiteMonarch : BlackMonarch;
1593 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++) {
1594 if(board[r][f] == k || board[r][f] == prince) {
1595 if(++royals > 1) return FALSE; // no check if we have two royals (ignores double captureby Lion!)
1596 king = board[r][f]; // remember hich one we had
1603 captured = board[rf][ft];
1604 board[rf][ft] = EmptySquare;
1606 captured = board[rt][ft];
1607 if(killX >= 0) { trampled = board[killY][killX]; board[killY][killX] = EmptySquare; }
1609 if(rf == DROP_RANK) board[rt][ft] = ff; else { // [HGM] drop
1610 board[rt][ft] = board[rf][ff];
1611 if(rf != rt || ff != ft) board[rf][ff] = EmptySquare;
1613 ep = board[EP_STATUS];
1614 if( captured == WhiteLion || captured == BlackLion ) { // [HGM] lion: Chu Lion-capture rules
1615 ChessSquare victim = killX < 0 ? EmptySquare : trampled;
1616 if( (board[rt][ft] == WhiteLion || board[rt][ft] == BlackLion) && // capturer is Lion
1617 (ff - ft > 1 || ft - ff > 1 || rf - rt > 1 || rt - rf > 1) && // captures from a distance
1618 (victim == EmptySquare || victim == WhitePawn || victim == BlackPawn) ) // no or worthless 'bridge'
1619 board[EP_STATUS] = EP_ROYAL_LION; // on distant Lion x Lion victim must not be pseudo-legally protected
1623 /* For compatibility with ICS wild 9, we scan the board in the
1624 order a1, a2, a3, ... b1, b2, ..., h8 to find the first king,
1625 and we test only whether that one is in check. */
1626 for (cl.fking = BOARD_LEFT+0; cl.fking < BOARD_RGHT; cl.fking++)
1627 for (cl.rking = 0; cl.rking < BOARD_HEIGHT; cl.rking++) {
1628 if (board[cl.rking][cl.fking] == king) {
1630 if(gameInfo.variant == VariantXiangqi) {
1631 /* [HGM] In Xiangqi opposing Kings means check as well */
1633 dir = (king >= BlackPawn) ? -1 : 1;
1634 for( i=cl.rking+dir; i>=0 && i<BOARD_HEIGHT &&
1635 board[i][cl.fking] == EmptySquare; i+=dir );
1636 if(i>=0 && i<BOARD_HEIGHT &&
1637 board[i][cl.fking] == (dir>0 ? BlackWazir : WhiteWazir) )
1640 GenPseudoLegal(board, flags ^ F_WHITE_ON_MOVE, CheckTestCallback, (VOIDSTAR) &cl, EmptySquare);
1641 if(gameInfo.variant != VariantSpartan || cl.check == 0) // in Spartan Chess go on to test if other King is checked too
1642 goto undo_move; /* 2-level break */
1649 if(rf != DROP_RANK) // [HGM] drop
1650 board[rf][ff] = board[rt][ft];
1652 board[rf][ft] = captured;
1653 board[rt][ft] = EmptySquare;
1655 if(killX >= 0) board[killY][killX] = trampled;
1656 board[rt][ft] = captured;
1658 board[EP_STATUS] = ep;
1661 return cl.fking < BOARD_RGHT ? cl.check : 1000; // [HGM] atomic: return 1000 if we have no king
1665 HasLion (Board board, int flags)
1667 int lion = F_WHITE_ON_MOVE & flags ? WhiteLion : BlackLion;
1669 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++)
1670 if(board[r][f] == lion) return 1;
1675 LegalDrop (Board board, int flags, ChessSquare piece, int rt, int ft)
1676 { // [HGM] put drop legality testing in separate routine for clarity
1678 if(appData.debugMode) fprintf(debugFP, "LegalDrop: %d @ %d,%d)\n", piece, ft, rt);
1679 if(board[rt][ft] != EmptySquare) return ImpossibleMove; // must drop to empty square
1680 n = PieceToNumber(piece);
1681 if((gameInfo.holdingsWidth == 0 || (flags & F_WHITE_ON_MOVE ? board[n][BOARD_WIDTH-1] : board[BOARD_HEIGHT-1-n][0]) != piece)
1682 && gameInfo.variant != VariantBughouse) // in bughouse we don't check for availability, because ICS doesn't always tell us
1683 return ImpossibleMove; // piece not available
1684 if(gameInfo.variant == VariantShogi) { // in Shogi lots of drops are forbidden!
1685 if((piece == WhitePawn || piece == WhiteQueen) && rt == BOARD_HEIGHT-1 ||
1686 (piece == BlackPawn || piece == BlackQueen) && rt == 0 ||
1687 piece == WhiteKnight && rt > BOARD_HEIGHT-3 ||
1688 piece == BlackKnight && rt < 2 ) return IllegalMove; // e.g. where dropped piece has no moves
1689 if(piece == WhitePawn || piece == BlackPawn) {
1690 int r, max = 1 + (BOARD_HEIGHT == 7); // two Pawns per file in Tori!
1691 for(r=1; r<BOARD_HEIGHT-1; r++)
1692 if(!(max -= (board[r][ft] == piece))) return IllegalMove; // or there already is a Pawn in file
1693 // should still test if we mate with this Pawn
1695 } else if(gameInfo.variant == VariantSChess) { // only back-rank drops
1696 if (rt != (piece < BlackPawn ? 0 : BOARD_HEIGHT-1)) return IllegalMove;
1698 if( (piece == WhitePawn || piece == BlackPawn) &&
1699 (rt == 0 || rt == BOARD_HEIGHT -1 ) )
1700 return IllegalMove; /* no pawn drops on 1st/8th */
1702 if(appData.debugMode) fprintf(debugFP, "LegalDrop: %d @ %d,%d)\n", piece, ft, rt);
1703 if (!(flags & F_IGNORE_CHECK) &&
1704 CheckTest(board, flags, DROP_RANK, piece, rt, ft, FALSE) ) return IllegalMove;
1705 return flags & F_WHITE_ON_MOVE ? WhiteDrop : BlackDrop;
1708 extern void LegalityTestCallback P((Board board, int flags, ChessMove kind,
1709 int rf, int ff, int rt, int ft,
1713 LegalityTestCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1715 register LegalityTestClosure *cl = (LegalityTestClosure *) closure;
1717 if(board[rt][ft] != EmptySquare || kind==WhiteCapturesEnPassant || kind==BlackCapturesEnPassant)
1718 cl->captures++; // [HGM] losers: count legal captures
1719 if (rf == cl->rf && ff == cl->ff && rt == cl->rt && ft == cl->ft)
1724 LegalityTest (Board board, int flags, int rf, int ff, int rt, int ft, int promoChar)
1726 LegalityTestClosure cl; ChessSquare piece, filterPiece;
1728 if(quickFlag) flags = flags & ~1 | quickFlag & 1; // [HGM] speed: in quick mode quickFlag specifies side-to-move.
1729 if(rf == DROP_RANK) return LegalDrop(board, flags, ff, rt, ft);
1730 piece = filterPiece = board[rf][ff];
1731 if(PieceToChar(piece) == '~') filterPiece = DEMOTED piece;
1733 /* [HGM] Cobra and Falcon are wildcard pieces; consider all their moves legal */
1734 /* (perhaps we should disallow moves that obviously leave us in check?) */
1735 if((piece == WhiteFalcon || piece == BlackFalcon ||
1736 piece == WhiteCobra || piece == BlackCobra) && gameInfo.variant != VariantChu && !pieceDesc[piece])
1737 return CheckTest(board, flags, rf, ff, rt, ft, FALSE) ? IllegalMove : NormalMove;
1741 cl.rt = rFilter = rt; // [HGM] speed: filter on to-square
1742 cl.ft = fFilter = ft;
1743 cl.kind = IllegalMove;
1744 cl.captures = 0; // [HGM] losers: prepare to count legal captures.
1745 if(flags & F_MANDATORY_CAPTURE) filterPiece = EmptySquare; // [HGM] speed: do not filter in suicide, to find all captures
1746 GenLegal(board, flags, LegalityTestCallback, (VOIDSTAR) &cl, filterPiece);
1747 if((flags & F_MANDATORY_CAPTURE) && cl.captures && board[rt][ft] == EmptySquare
1748 && cl.kind != WhiteCapturesEnPassant && cl.kind != BlackCapturesEnPassant)
1749 return(IllegalMove); // [HGM] losers: if there are legal captures, non-capts are illegal
1751 if(promoChar == 'x') promoChar = NULLCHAR; // [HGM] is this ever the case?
1752 if(gameInfo.variant == VariantSChess && promoChar && promoChar != '=' && board[rf][ff] != WhitePawn && board[rf][ff] != BlackPawn) {
1753 if(board[rf][ff] < BlackPawn) { // white
1754 if(rf != 0) return IllegalMove; // must be on back rank
1755 if(!(board[VIRGIN][ff] & VIRGIN_W)) return IllegalMove; // non-virgin
1756 if(board[PieceToNumber(CharToPiece(ToUpper(promoChar)))][BOARD_WIDTH-2] == 0) return ImpossibleMove;// must be in stock
1757 if(cl.kind == WhiteHSideCastleFR && (ff == BOARD_RGHT-2 || ff == BOARD_RGHT-3)) return ImpossibleMove;
1758 if(cl.kind == WhiteASideCastleFR && (ff == BOARD_LEFT+2 || ff == BOARD_LEFT+3)) return ImpossibleMove;
1760 if(rf != BOARD_HEIGHT-1) return IllegalMove;
1761 if(!(board[VIRGIN][ff] & VIRGIN_B)) return IllegalMove; // non-virgin
1762 if(board[BOARD_HEIGHT-1-PieceToNumber(CharToPiece(ToLower(promoChar)))][1] == 0) return ImpossibleMove;
1763 if(cl.kind == BlackHSideCastleFR && (ff == BOARD_RGHT-2 || ff == BOARD_RGHT-3)) return ImpossibleMove;
1764 if(cl.kind == BlackASideCastleFR && (ff == BOARD_LEFT+2 || ff == BOARD_LEFT+3)) return ImpossibleMove;
1767 if(gameInfo.variant == VariantChu) {
1768 if(cl.kind != NormalMove || promoChar == NULLCHAR || promoChar == '=') return cl.kind;
1769 if(promoChar != '+')
1770 return CharToPiece(promoChar) == EmptySquare ? ImpossibleMove : IllegalMove;
1771 if(PieceToChar(CHUPROMOTED board[rf][ff]) != '+') return ImpossibleMove;
1772 return flags & F_WHITE_ON_MOVE ? WhitePromotion : BlackPromotion;
1774 if(gameInfo.variant == VariantShogi) {
1775 /* [HGM] Shogi promotions. '=' means defer */
1776 if(rf != DROP_RANK && cl.kind == NormalMove) {
1777 ChessSquare piece = board[rf][ff];
1779 if(promoChar == PieceToChar(BlackQueen)) promoChar = NULLCHAR; /* [HGM] Kludge */
1780 if(promoChar == 'd' && (piece == WhiteRook || piece == BlackRook) ||
1781 promoChar == 'h' && (piece == WhiteBishop || piece == BlackBishop) ||
1782 promoChar == 'g' && (piece <= WhiteFerz || piece <= BlackFerz && piece >= BlackPawn) )
1783 promoChar = '+'; // allowed ICS notations
1784 if(appData.debugMode)fprintf(debugFP,"SHOGI promoChar = %c\n", promoChar ? promoChar : '-');
1785 if(promoChar != NULLCHAR && promoChar != '+' && promoChar != '=')
1786 return CharToPiece(promoChar) == EmptySquare ? ImpossibleMove : IllegalMove;
1787 else if(flags & F_WHITE_ON_MOVE) {
1788 if( (int) piece < (int) WhiteWazir &&
1789 (rf >= BOARD_HEIGHT - BOARD_HEIGHT/3 || rt >= BOARD_HEIGHT - BOARD_HEIGHT/3) ) {
1790 if( (piece == WhitePawn || piece == WhiteQueen) && rt > BOARD_HEIGHT-2 ||
1791 piece == WhiteKnight && rt > BOARD_HEIGHT-3) /* promotion mandatory */
1792 cl.kind = promoChar == '=' ? IllegalMove : WhitePromotion;
1793 else /* promotion optional, default is defer */
1794 cl.kind = promoChar == '+' ? WhitePromotion : WhiteNonPromotion;
1795 } else cl.kind = promoChar == '+' ? IllegalMove : NormalMove;
1797 if( (int) piece < (int) BlackWazir && (rf < BOARD_HEIGHT/3 || rt < BOARD_HEIGHT/3) ) {
1798 if( (piece == BlackPawn || piece == BlackQueen) && rt < 1 ||
1799 piece == BlackKnight && rt < 2 ) /* promotion obligatory */
1800 cl.kind = promoChar == '=' ? IllegalMove : BlackPromotion;
1801 else /* promotion optional, default is defer */
1802 cl.kind = promoChar == '+' ? BlackPromotion : BlackNonPromotion;
1803 } else cl.kind = promoChar == '+' ? IllegalMove : NormalMove;
1807 if (promoChar != NULLCHAR) {
1808 if(cl.kind == NormalMove && promoChar == '+') { // allow shogi-style promotion is pieceToChar specifies them
1809 ChessSquare piece = board[rf][ff];
1810 if(piece < BlackPawn ? piece > WhiteMan : piece > BlackMan) return ImpossibleMove; // already promoted
1811 // should test if in zone, really
1812 if(gameInfo.variant == VariantChuChess && (piece == WhiteKnight || piece == BlackKnight) && HasLion(board, flags))
1814 if(PieceToChar(PROMOTED piece) == '+') return flags & F_WHITE_ON_MOVE ? WhitePromotion : BlackPromotion;
1816 if(promoChar == '=') cl.kind = IllegalMove; else // [HGM] shogi: no deferred promotion outside Shogi
1817 if (cl.kind == WhitePromotion || cl.kind == BlackPromotion) {
1818 ChessSquare piece = CharToPiece(flags & F_WHITE_ON_MOVE ? ToUpper(promoChar) : ToLower(promoChar));
1819 if(piece == EmptySquare)
1820 cl.kind = ImpossibleMove; // non-existing piece
1821 if(gameInfo.variant == VariantChuChess && promoChar == 'l' && HasLion(board, flags)) {
1822 cl.kind = IllegalMove; // no two Lions
1823 } else if(gameInfo.variant == VariantSpartan && cl.kind == BlackPromotion ) {
1824 if(promoChar != PieceToChar(BlackKing)) {
1825 if(CheckTest(board, flags, rf, ff, rt, ft, FALSE)) cl.kind = IllegalMove; // [HGM] spartan: only promotion to King was possible
1826 if(piece == BlackLance) cl.kind = ImpossibleMove;
1827 } else { // promotion to King allowed only if we do not have two yet
1828 int r, f, kings = 0;
1829 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++) kings += (board[r][f] == BlackKing);
1830 if(kings == 2) cl.kind = IllegalMove;
1832 } else if(piece == WhitePawn && rt == BOARD_HEIGHT-1 ||
1833 piece == BlackPawn && rt == 0) cl.kind = IllegalMove; // cannot stay Pawn on last rank in any variant
1834 else if((piece == WhiteUnicorn || piece == BlackUnicorn) && gameInfo.variant == VariantKnightmate)
1835 cl.kind = IllegalMove; // promotion to Royal Knight not allowed
1836 else if((piece == WhiteKing || piece == BlackKing) && gameInfo.variant != VariantSuicide && gameInfo.variant != VariantGiveaway)
1837 cl.kind = IllegalMove; // promotion to King usually not allowed
1839 cl.kind = IllegalMove;
1849 extern void MateTestCallback P((Board board, int flags, ChessMove kind,
1850 int rf, int ff, int rt, int ft,
1854 MateTestCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1856 register MateTestClosure *cl = (MateTestClosure *) closure;
1861 /* Return MT_NONE, MT_CHECK, MT_CHECKMATE, or MT_STALEMATE */
1863 MateTest (Board board, int flags)
1866 int inCheck, r, f, myPieces=0, hisPieces=0, nrKing=0;
1867 ChessSquare king = flags & F_WHITE_ON_MOVE ? WhiteKing : BlackKing;
1869 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++) {
1870 // [HGM] losers: Count pieces and kings, to detect other unorthodox winning conditions
1871 nrKing += (board[r][f] == king); // stm has king
1872 if( board[r][f] != EmptySquare ) {
1873 if((int)board[r][f] <= (int)king && (int)board[r][f] >= (int)king - (int)WhiteKing + (int)WhitePawn)
1878 switch(gameInfo.variant) { // [HGM] losers: extinction wins
1879 case VariantShatranj:
1880 if(hisPieces == 1) return myPieces > 1 ? MT_BARE : MT_DRAW;
1884 if(nrKing == 0) return MT_NOKING;
1887 if(myPieces == 1) return MT_BARE;
1890 inCheck = GenLegal(board, flags, MateTestCallback, (VOIDSTAR) &cl, EmptySquare);
1891 // [HGM] 3check: yet to do!
1893 return inCheck ? MT_CHECK : MT_NONE;
1895 if(gameInfo.holdingsWidth && gameInfo.variant != VariantSuper && gameInfo.variant != VariantGreat
1896 && gameInfo.variant != VariantSChess && gameInfo.variant != VariantGrand) { // drop game
1897 int r, f, n, holdings = flags & F_WHITE_ON_MOVE ? BOARD_WIDTH-1 : 0;
1898 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++) if(board[r][f] == EmptySquare) // all empty squares
1899 for(n=0; n<BOARD_HEIGHT; n++) // all pieces in hand
1900 if(board[n][holdings] != EmptySquare) {
1901 int moveType = LegalDrop(board, flags, board[n][holdings], r, f);
1902 if(moveType == WhiteDrop || moveType == BlackDrop) return (inCheck ? MT_CHECK : MT_NONE); // we have legal drop
1905 if(gameInfo.variant == VariantSuicide) // [HGM] losers: always stalemate, since no check, but result varies
1906 return myPieces == hisPieces ? MT_STALEMATE :
1907 myPieces > hisPieces ? MT_STAINMATE : MT_STEALMATE;
1908 else if(gameInfo.variant == VariantLosers) return inCheck ? MT_TRICKMATE : MT_STEALMATE;
1909 else if(gameInfo.variant == VariantGiveaway) return MT_STEALMATE; // no check exists, stalemated = win
1911 return inCheck ? MT_CHECKMATE
1912 : (gameInfo.variant == VariantXiangqi || gameInfo.variant == VariantShatranj || IS_SHOGI(gameInfo.variant)) ?
1913 MT_STAINMATE : MT_STALEMATE;
1918 extern void DisambiguateCallback P((Board board, int flags, ChessMove kind,
1919 int rf, int ff, int rt, int ft,
1923 DisambiguateCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
1925 register DisambiguateClosure *cl = (DisambiguateClosure *) closure;
1926 int wildCard = FALSE; ChessSquare piece = board[rf][ff];
1928 // [HGM] wild: for wild-card pieces rt and rf are dummies
1929 if(piece == WhiteFalcon || piece == BlackFalcon ||
1930 piece == WhiteCobra || piece == BlackCobra)
1933 if ((cl->pieceIn == EmptySquare || cl->pieceIn == board[rf][ff]
1934 || PieceToChar(board[rf][ff]) == '~'
1935 && cl->pieceIn == (ChessSquare)(DEMOTED board[rf][ff])
1937 (cl->rfIn == -1 || cl->rfIn == rf) &&
1938 (cl->ffIn == -1 || cl->ffIn == ff) &&
1939 (cl->rtIn == -1 || cl->rtIn == rt || wildCard) &&
1940 (cl->ftIn == -1 || cl->ftIn == ft || wildCard)) {
1942 if(cl->count && rf == cl->rf && ff == cl->ff) return; // duplicate move
1945 if(cl->count == 1 || board[rt][ft] != EmptySquare) {
1946 // [HGM] oneclick: if multiple moves, be sure we remember capture
1947 cl->piece = board[rf][ff];
1950 cl->rt = wildCard ? cl->rtIn : rt;
1951 cl->ft = wildCard ? cl->ftIn : ft;
1954 cl->captures += (board[rt][ft] != EmptySquare); // [HGM] oneclick: count captures
1959 Disambiguate (Board board, int flags, DisambiguateClosure *closure)
1961 int illegal = 0; char c = closure->promoCharIn;
1963 if(quickFlag) flags = flags & ~1 | quickFlag & 1; // [HGM] speed: in quick mode quickFlag specifies side-to-move.
1964 closure->count = closure->captures = 0;
1965 closure->rf = closure->ff = closure->rt = closure->ft = 0;
1966 closure->kind = ImpossibleMove;
1967 rFilter = closure->rtIn; // [HGM] speed: only consider moves to given to-square
1968 fFilter = closure->ftIn;
1969 if(quickFlag) { // [HGM] speed: try without check test first, because if that is not ambiguous, we are happy
1970 GenLegal(board, flags|F_IGNORE_CHECK, DisambiguateCallback, (VOIDSTAR) closure, closure->pieceIn);
1971 if(closure->count > 1) { // gamble did not pay off. retry with check test to resolve ambiguity
1972 closure->count = closure->captures = 0;
1973 closure->rf = closure->ff = closure->rt = closure->ft = 0;
1974 closure->kind = ImpossibleMove;
1975 GenLegal(board, flags, DisambiguateCallback, (VOIDSTAR) closure, closure->pieceIn); // [HGM] speed: only pieces of requested type
1978 GenLegal(board, flags, DisambiguateCallback, (VOIDSTAR) closure, closure->pieceIn); // [HGM] speed: only pieces of requested type
1979 if (closure->count == 0) {
1980 /* See if it's an illegal move due to check */
1982 GenLegal(board, flags|F_IGNORE_CHECK, DisambiguateCallback, (VOIDSTAR) closure, closure->pieceIn);
1983 if (closure->count == 0) {
1984 /* No, it's not even that */
1985 if(!appData.testLegality && closure->pieceIn != EmptySquare) {
1986 int f, r; // if there is only a single piece of the requested type on the board, use that
1987 closure->rt = closure->rtIn, closure->ft = closure->ftIn;
1988 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++)
1989 if(board[r][f] == closure->pieceIn) closure->count++, closure->rf = r, closure->ff = f;
1990 if(closure->count > 1) illegal = 0; // ambiguous
1992 if(closure->count == 0) {
1993 if (appData.debugMode) { int i, j;
1994 for(i=BOARD_HEIGHT-1; i>=0; i--) {
1995 for(j=0; j<BOARD_WIDTH; j++)
1996 fprintf(debugFP, "%3d", (int) board[i][j]);
1997 fprintf(debugFP, "\n");
2003 } else if(pieceDefs && closure->count > 1) { // [HGM] gen: move is ambiguous under engine-defined rules
2004 DisambiguateClosure spare = *closure;
2005 pieceDefs = FALSE; spare.count = 0; // See if the (erroneous) built-in rules would resolve that
2006 GenLegal(board, flags, DisambiguateCallback, (VOIDSTAR) &spare, closure->pieceIn);
2007 if(spare.count == 1) *closure = spare; // It does, so use those in stead (game from file saved before gen patch?)
2011 if (c == 'x') c = NULLCHAR; // get rid of any 'x' (which should never happen?)
2012 if(gameInfo.variant == VariantSChess && c && c != '=' && closure->piece != WhitePawn && closure->piece != BlackPawn) {
2013 if(closure->piece < BlackPawn) { // white
2014 if(closure->rf != 0) closure->kind = IllegalMove; // must be on back rank
2015 if(!(board[VIRGIN][closure->ff] & VIRGIN_W)) closure->kind = IllegalMove; // non-virgin
2016 if(board[PieceToNumber(CharToPiece(ToUpper(c)))][BOARD_WIDTH-2] == 0) closure->kind = ImpossibleMove;// must be in stock
2017 if(closure->kind == WhiteHSideCastleFR && (closure->ff == BOARD_RGHT-2 || closure->ff == BOARD_RGHT-3)) closure->kind = ImpossibleMove;
2018 if(closure->kind == WhiteASideCastleFR && (closure->ff == BOARD_LEFT+2 || closure->ff == BOARD_LEFT+3)) closure->kind = ImpossibleMove;
2020 if(closure->rf != BOARD_HEIGHT-1) closure->kind = IllegalMove;
2021 if(!(board[VIRGIN][closure->ff] & VIRGIN_B)) closure->kind = IllegalMove; // non-virgin
2022 if(board[BOARD_HEIGHT-1-PieceToNumber(CharToPiece(ToLower(c)))][1] == 0) closure->kind = ImpossibleMove;
2023 if(closure->kind == BlackHSideCastleFR && (closure->ff == BOARD_RGHT-2 || closure->ff == BOARD_RGHT-3)) closure->kind = ImpossibleMove;
2024 if(closure->kind == BlackASideCastleFR && (closure->ff == BOARD_LEFT+2 || closure->ff == BOARD_LEFT+3)) closure->kind = ImpossibleMove;
2027 if(gameInfo.variant == VariantChu) {
2028 if(c == '+') closure->kind = (flags & F_WHITE_ON_MOVE ? WhitePromotion : BlackPromotion); // for now, accept any
2030 if(gameInfo.variant == VariantShogi) {
2031 /* [HGM] Shogi promotions. On input, '=' means defer, '+' promote. Afterwards, c is set to '+' for promotions, NULL other */
2032 if(closure->rfIn != DROP_RANK && closure->kind == NormalMove) {
2033 ChessSquare piece = closure->piece;
2034 if (c == 'd' && (piece == WhiteRook || piece == BlackRook) ||
2035 c == 'h' && (piece == WhiteBishop || piece == BlackBishop) ||
2036 c == 'g' && (piece <= WhiteFerz || piece <= BlackFerz && piece >= BlackPawn) )
2037 c = '+'; // allowed ICS notations
2038 if(c != NULLCHAR && c != '+' && c != '=') closure->kind = IllegalMove; // otherwise specifying a piece is illegal
2039 else if(flags & F_WHITE_ON_MOVE) {
2040 if( (int) piece < (int) WhiteWazir &&
2041 (closure->rf >= BOARD_HEIGHT-(BOARD_HEIGHT/3) || closure->rt >= BOARD_HEIGHT-(BOARD_HEIGHT/3)) ) {
2042 if( (piece == WhitePawn || piece == WhiteQueen) && closure->rt > BOARD_HEIGHT-2 ||
2043 piece == WhiteKnight && closure->rt > BOARD_HEIGHT-3) /* promotion mandatory */
2044 closure->kind = c == '=' ? IllegalMove : WhitePromotion;
2045 else /* promotion optional, default is defer */
2046 closure->kind = c == '+' ? WhitePromotion : WhiteNonPromotion;
2047 } else closure->kind = c == '+' ? IllegalMove : NormalMove;
2049 if( (int) piece < (int) BlackWazir && (closure->rf < BOARD_HEIGHT/3 || closure->rt < BOARD_HEIGHT/3) ) {
2050 if( (piece == BlackPawn || piece == BlackQueen) && closure->rt < 1 ||
2051 piece == BlackKnight && closure->rt < 2 ) /* promotion obligatory */
2052 closure->kind = c == '=' ? IllegalMove : BlackPromotion;
2053 else /* promotion optional, default is defer */
2054 closure->kind = c == '+' ? BlackPromotion : BlackNonPromotion;
2055 } else closure->kind = c == '+' ? IllegalMove : NormalMove;
2058 if(closure->kind == WhitePromotion || closure->kind == BlackPromotion) c = '+'; else
2059 if(closure->kind == WhiteNonPromotion || closure->kind == BlackNonPromotion) c = '=';
2061 if (closure->kind == WhitePromotion || closure->kind == BlackPromotion) {
2062 if(c == NULLCHAR) { // missing promoChar on mandatory promotion; use default for variant
2063 if(gameInfo.variant == VariantShatranj || gameInfo.variant == VariantCourier ||
2064 gameInfo.variant == VariantMakruk || gameInfo.variant == VariantASEAN)
2065 c = PieceToChar(BlackFerz);
2066 else if(gameInfo.variant == VariantGreat)
2067 c = PieceToChar(BlackMan);
2068 else if(gameInfo.variant == VariantGrand)
2069 closure->kind = closure->rt != 0 && closure->rt != BOARD_HEIGHT-1 ? NormalMove : AmbiguousMove; // no default in Grand Chess
2071 c = PieceToChar(BlackQueen);
2072 } else if(c == '=') closure->kind = IllegalMove; // no deferral outside Shogi
2073 else if(c == 'l' && gameInfo.variant == VariantChuChess && HasLion(board, flags)) closure->kind = IllegalMove;
2074 } else if (c == '+') { // '+' outside shogi, check if pieceToCharTable enabled it
2075 ChessSquare p = closure->piece;
2076 if(p > WhiteMan && p < BlackPawn || p > BlackMan || PieceToChar(PROMOTED p) != '+')
2077 closure->kind = ImpossibleMove; // used on non-promotable piece
2078 else if(gameInfo.variant == VariantChuChess && HasLion(board, flags)) closure->kind = IllegalMove;
2079 } else if (c != NULLCHAR) closure->kind = IllegalMove;
2081 closure->promoChar = ToLower(c); // this can be NULLCHAR! Note we keep original promoChar even if illegal.
2082 if(c != '+' && c != '=' && c != NULLCHAR && CharToPiece(flags & F_WHITE_ON_MOVE ? ToUpper(c) : ToLower(c)) == EmptySquare)
2083 closure->kind = ImpossibleMove; // but we cannot handle non-existing piece types!
2084 if (closure->count > 1) {
2085 closure->kind = AmbiguousMove;
2088 /* Note: If more than one illegal move matches, but no legal
2089 moves, we return IllegalMove, not AmbiguousMove. Caller
2090 can look at closure->count to detect this.
2092 closure->kind = IllegalMove;
2106 } CoordsToAlgebraicClosure;
2108 extern void CoordsToAlgebraicCallback P((Board board, int flags,
2109 ChessMove kind, int rf, int ff,
2110 int rt, int ft, VOIDSTAR closure));
2113 CoordsToAlgebraicCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
2115 register CoordsToAlgebraicClosure *cl =
2116 (CoordsToAlgebraicClosure *) closure;
2118 if ((rt == cl->rt && ft == cl->ft || rt == rf && ft == ff) && // [HGM] null move matches any toSquare
2119 (board[rf][ff] == cl->piece
2120 || PieceToChar(board[rf][ff]) == '~' &&
2121 (ChessSquare) (DEMOTED board[rf][ff]) == cl->piece)
2125 cl->kind = kind; /* this is the move we want */
2127 cl->file++; /* need file to rule out this move */
2131 cl->rank++; /* need rank to rule out this move */
2133 cl->either++; /* rank or file will rule out this move */
2139 /* Convert coordinates to normal algebraic notation.
2140 promoChar must be NULLCHAR or 'x' if not a promotion.
2143 CoordsToAlgebraic (Board board, int flags, int rf, int ff, int rt, int ft, int promoChar, char out[MOVE_LEN])
2147 char *outp = out, c, capture;
2148 CoordsToAlgebraicClosure cl;
2150 if (rf == DROP_RANK) {
2151 if(ff == EmptySquare) { strncpy(outp, "--",3); return NormalMove; } // [HGM] pass
2152 /* Bughouse piece drop */
2153 *outp++ = ToUpper(PieceToChar((ChessSquare) ff));
2158 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2160 return (flags & F_WHITE_ON_MOVE) ? WhiteDrop : BlackDrop;
2163 if (promoChar == 'x') promoChar = NULLCHAR;
2164 piece = board[rf][ff];
2165 if(PieceToChar(piece)=='~') piece = (ChessSquare)(DEMOTED piece);
2170 kind = LegalityTest(board, flags, rf, ff, rt, ft, promoChar);
2171 if (kind == IllegalMove && !(flags&F_IGNORE_CHECK)) {
2172 /* Keep short notation if move is illegal only because it
2173 leaves the player in check, but still return IllegalMove */
2174 kind = LegalityTest(board, flags|F_IGNORE_CHECK, rf, ff, rt, ft, promoChar);
2175 if (kind == IllegalMove) break;
2180 capture = board[rt][ft] != EmptySquare || kind == WhiteCapturesEnPassant || kind == BlackCapturesEnPassant;
2181 if (ff == ft && !capture) { /* [HGM] Xiangqi has straight noncapts! */
2182 /* Non-capture; use style "e5" */
2185 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2187 /* Capture; use style "exd5" */
2189 *outp++ = 'x'; /* [HGM] Xiangqi has sideway noncaptures across river! */
2193 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2195 /* Use promotion suffix style "=Q" */
2197 if (promoChar != NULLCHAR) {
2198 if(IS_SHOGI(gameInfo.variant)) {
2199 /* [HGM] ... but not in Shogi! */
2200 *outp++ = promoChar == '=' ? '=' : '+';
2203 *outp++ = ToUpper(promoChar);
2212 /* Fabien moved code: FRC castling first (if KxR), wild castling second */
2213 /* Code added by Tord: FRC castling. */
2214 if((piece == WhiteKing && board[rt][ft] == WhiteRook) ||
2215 (piece == BlackKing && board[rt][ft] == BlackRook)) {
2217 safeStrCpy(out, "O-O", MOVE_LEN);
2219 safeStrCpy(out, "O-O-O", MOVE_LEN);
2220 return LegalityTest(board, flags, rf, ff, rt, ft, promoChar);
2222 /* End of code added by Tord */
2223 /* Test for castling or ICS wild castling */
2224 /* Use style "O-O" (oh-oh) for PGN compatibility */
2225 else if (rf == rt &&
2226 rf == ((piece == WhiteKing) ? 0 : BOARD_HEIGHT-1) &&
2227 (ft - ff > 1 || ff - ft > 1) && // No castling if legal King move (on narrow boards!)
2228 ((ff == BOARD_WIDTH>>1 && (ft == BOARD_LEFT+2 || ft == BOARD_RGHT-2)) ||
2229 (ff == (BOARD_WIDTH-1)>>1 && (ft == BOARD_LEFT+1 || ft == BOARD_RGHT-3)))) {
2230 if(ft==BOARD_LEFT+1 || ft==BOARD_RGHT-2)
2231 snprintf(out, MOVE_LEN, "O-O%c%c", promoChar ? '/' : 0, ToUpper(promoChar));
2233 snprintf(out, MOVE_LEN, "O-O-O%c%c", promoChar ? '/' : 0, ToUpper(promoChar));
2235 /* This notation is always unambiguous, unless there are
2236 kings on both the d and e files, with "wild castling"
2237 possible for the king on the d file and normal castling
2238 possible for the other. ICS rules for wild 9
2239 effectively make castling illegal for either king in
2240 this situation. So I am not going to worry about it;
2241 I'll just generate an ambiguous O-O in this case.
2243 return LegalityTest(board, flags, rf, ff, rt, ft, promoChar);
2246 /* else fall through */
2251 cl.rt = rFilter = rt; // [HGM] speed: filter on to-square
2252 cl.ft = fFilter = ft;
2254 cl.kind = IllegalMove;
2255 cl.rank = cl.file = cl.either = 0;
2256 c = PieceToChar(piece) ;
2257 GenLegal(board, flags, CoordsToAlgebraicCallback, (VOIDSTAR) &cl, c!='~' ? piece : (DEMOTED piece)); // [HGM] speed
2259 if (cl.kind == IllegalMove && !(flags&F_IGNORE_CHECK)) {
2260 /* Generate pretty moves for moving into check, but
2261 still return IllegalMove.
2263 GenLegal(board, flags|F_IGNORE_CHECK, CoordsToAlgebraicCallback, (VOIDSTAR) &cl, c!='~' ? piece : (DEMOTED piece));
2264 if (cl.kind == IllegalMove) break;
2265 cl.kind = IllegalMove;
2268 /* Style is "Nf3" or "Nxf7" if this is unambiguous,
2269 else "Ngf3" or "Ngxf7",
2270 else "N1f3" or "N5xf7",
2271 else "Ng1f3" or "Ng5xf7".
2273 if( c == '~' || c == '+') {
2274 /* [HGM] print nonexistent piece as its demoted version */
2275 piece = (ChessSquare) (DEMOTED piece - 11*(gameInfo.variant == VariantChu));
2277 if(c=='+') *outp++ = c;
2278 *outp++ = ToUpper(PieceToChar(piece));
2280 if (cl.file || (cl.either && !cl.rank)) {
2286 else { *outp++ = (rf+ONE-'0')/10 + '0';*outp++ = (rf+ONE-'0')%10 + '0'; }
2289 if(board[rt][ft] != EmptySquare)
2295 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2296 if (IS_SHOGI(gameInfo.variant)) {
2297 /* [HGM] in Shogi non-pawns can promote */
2298 *outp++ = promoChar; // Don't bother to correct move type, return value is never used!
2300 else if (gameInfo.variant == VariantChuChess && promoChar ||
2301 gameInfo.variant != VariantSuper && promoChar &&
2302 (piece == WhiteLance || piece == BlackLance) ) { // Lance sometimes represents Pawn
2304 *outp++ = ToUpper(promoChar);
2306 else if (gameInfo.variant == VariantSChess && promoChar) { // and in S-Chess we have gating
2308 *outp++ = ToUpper(promoChar);
2314 /* Moving a nonexistent piece */
2318 /* Not a legal move, even ignoring check.
2319 If there was a piece on the from square,
2320 use style "Ng1g3" or "Ng1xe8";
2321 if there was a pawn or nothing (!),
2322 use style "g1g3" or "g1xe8". Use "x"
2323 if a piece was on the to square, even
2324 a piece of the same color.
2328 if (piece != EmptySquare && piece != WhitePawn && piece != BlackPawn) {
2330 for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<=BOARD_RGHT; f++)
2331 c += (board[r][f] == piece); // count on-board pieces of given type
2332 *outp++ = ToUpper(PieceToChar(piece));
2334 if(c != 1) { // [HGM] but if there is only one piece of the mentioned type, no from-square, thank you!
2338 else { *outp++ = (rf+ONE-'0')/10 + '0';*outp++ = (rf+ONE-'0')%10 + '0'; }
2340 if (board[rt][ft] != EmptySquare) *outp++ = 'x';
2344 else { *outp++ = (rt+ONE-'0')/10 + '0';*outp++ = (rt+ONE-'0')%10 + '0'; }
2345 /* Use promotion suffix style "=Q" */
2346 if (promoChar != NULLCHAR && promoChar != 'x') {
2348 *outp++ = ToUpper(promoChar);
2355 // [HGM] XQ: the following code serves to detect perpetual chasing (Asian rules)
2364 // I guess the following variables logically belong in the closure too, but I was too lazy and used globals
2366 int preyStackPointer, chaseStackPointer;
2369 unsigned char rf, ff, rt, ft;
2373 unsigned char rank, file;
2379 // there are three new callbacks for use with GenLegal: for adding captures, deleting them, and finding a recapture
2381 extern void AtacksCallback P((Board board, int flags, ChessMove kind,
2382 int rf, int ff, int rt, int ft,
2386 AttacksCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
2387 { // For adding captures that can lead to chase indictment to the chaseStack
2388 if(board[rt][ft] == EmptySquare) return; // non-capture
2389 if(board[rt][ft] == WhitePawn && rt < BOARD_HEIGHT/2) return; // Pawn before river can be chased
2390 if(board[rt][ft] == BlackPawn && rt >= BOARD_HEIGHT/2) return; // Pawn before river can be chased
2391 if(board[rf][ff] == WhitePawn || board[rf][ff] == BlackPawn) return; // Pawns are allowed to chase
2392 if(board[rf][ff] == WhiteWazir || board[rf][ff] == BlackWazir) return; // King is allowed to chase
2393 // move cannot be excluded from being a chase trivially (based on attacker and victim); save it on chaseStack
2394 chaseStack[chaseStackPointer].rf = rf;
2395 chaseStack[chaseStackPointer].ff = ff;
2396 chaseStack[chaseStackPointer].rt = rt;
2397 chaseStack[chaseStackPointer].ft = ft;
2398 chaseStackPointer++;
2401 extern void ExistingAtacksCallback P((Board board, int flags, ChessMove kind,
2402 int rf, int ff, int rt, int ft,
2406 ExistingAttacksCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
2407 { // for removing pre-exsting captures from the chaseStack, to be left with newly created ones
2409 register ChaseClosure *cl = (ChaseClosure *) closure; //closure tells us the move played in the repeat loop
2411 if(board[rt][ft] == EmptySquare) return; // no capture
2412 if(rf == cl->rf && ff == cl->ff) { // attacks with same piece from new position are not considered new
2413 rf = cl->rt; ff = cl->ft; // doctor their fromSquare so they will be recognized in chaseStack
2415 // search move in chaseStack, and delete it if it occurred there (as we know now it is not a new capture)
2416 for(i=0; i<chaseStackPointer; i++) {
2417 if(chaseStack[i].rf == rf && chaseStack[i].ff == ff &&
2418 chaseStack[i].rt == rt && chaseStack[i].ft == ft ) {
2419 // move found on chaseStack, delete it by overwriting with move popped from top of chaseStack
2420 chaseStack[i] = chaseStack[--chaseStackPointer];
2426 extern void ProtectedCallback P((Board board, int flags, ChessMove kind,
2427 int rf, int ff, int rt, int ft,
2431 ProtectedCallback (Board board, int flags, ChessMove kind, int rf, int ff, int rt, int ft, VOIDSTAR closure)
2432 { // for determining if a piece (given through the closure) is protected
2433 register ChaseClosure *cl = (ChaseClosure *) closure; // closure tells us where to recapture
2435 if(rt == cl->rt && ft == cl->ft) cl->recaptures++; // count legal recaptures to this square
2436 if(appData.debugMode && board[rt][ft] != EmptySquare)
2437 fprintf(debugFP, "try %c%c%c%c=%d\n", ff+AAA, rf+ONE,ft+AAA, rt+ONE, cl->recaptures);
2440 extern char moveList[MAX_MOVES][MOVE_LEN];
2443 PerpetualChase (int first, int last)
2444 { // this routine detects if the side to move in the 'first' position is perpetually chasing (when not checking)
2447 ChessSquare captured;
2449 preyStackPointer = 0; // clear stack of chased pieces
2450 for(i=first; i<last; i+=2) { // for all positions with same side to move
2451 if(appData.debugMode) fprintf(debugFP, "judge position %i\n", i);
2452 chaseStackPointer = 0; // clear stack that is going to hold possible chases
2453 // determine all captures possible after the move, and put them on chaseStack
2454 GenLegal(boards[i+1], PosFlags(i), AttacksCallback, &cl, EmptySquare);
2455 if(appData.debugMode) { int n;
2456 for(n=0; n<chaseStackPointer; n++)
2457 fprintf(debugFP, "%c%c%c%c ", chaseStack[n].ff+AAA, chaseStack[n].rf+ONE,
2458 chaseStack[n].ft+AAA, chaseStack[n].rt+ONE);
2459 fprintf(debugFP, ": all capts\n");
2461 // determine all captures possible before the move, and delete them from chaseStack
2462 cl.rf = moveList[i][1]-ONE; // prepare closure to pass move that led from i to i+1
2463 cl.ff = moveList[i][0]-AAA+BOARD_LEFT;
2464 cl.rt = moveList[i][3]-ONE;
2465 cl.ft = moveList[i][2]-AAA+BOARD_LEFT;
2466 CopyBoard(xqCheckers, nullBoard); xqCheckers[EP_STATUS] = 1; // giant kludge to make GenLegal ignore pre-existing checks
2467 GenLegal(boards[i], PosFlags(i), ExistingAttacksCallback, &cl, EmptySquare);
2468 xqCheckers[EP_STATUS] = 0; // disable the generation of quasi-legal moves again
2469 if(appData.debugMode) { int n;
2470 for(n=0; n<chaseStackPointer; n++)
2471 fprintf(debugFP, "%c%c%c%c ", chaseStack[n].ff+AAA, chaseStack[n].rf+ONE,
2472 chaseStack[n].ft+AAA, chaseStack[n].rt+ONE);
2473 fprintf(debugFP, ": new capts after %c%c%c%c\n", cl.ff+AAA, cl.rf+ONE, cl.ft+AAA, cl.rt+ONE);
2475 // chaseSack now contains all captures made possible by the move
2476 for(j=0; j<chaseStackPointer; j++) { // run through chaseStack to identify true chases
2477 int attacker = (int)boards[i+1][chaseStack[j].rf][chaseStack[j].ff];
2478 int victim = (int)boards[i+1][chaseStack[j].rt][chaseStack[j].ft];
2480 if(attacker >= (int) BlackPawn) attacker = BLACK_TO_WHITE attacker; // convert to white, as piecee type
2481 if(victim >= (int) BlackPawn) victim = BLACK_TO_WHITE victim;
2483 if((attacker == WhiteKnight || attacker == WhiteCannon) && victim == WhiteRook)
2484 continue; // C or H attack on R is always chase; leave on chaseStack
2486 if(attacker == victim) {
2487 if(LegalityTest(boards[i+1], PosFlags(i+1), chaseStack[j].rt,
2488 chaseStack[j].ft, chaseStack[j].rf, chaseStack[j].ff, NULLCHAR) == NormalMove) {
2489 // we can capture back with equal piece, so this is no chase but a sacrifice
2490 chaseStack[j] = chaseStack[--chaseStackPointer]; // delete the capture from the chaseStack
2491 j--; /* ! */ continue;
2496 // the attack is on a lower piece, or on a pinned or blocked equal one
2497 CopyBoard(xqCheckers, nullBoard); xqCheckers[EP_STATUS] = 1;
2498 CheckTest(boards[i+1], PosFlags(i+1), -1, -1, -1, -1, FALSE); // if we deliver check with our move, the checkers get marked
2499 // test if the victim is protected by a true protector. First make the capture.
2500 captured = boards[i+1][chaseStack[j].rt][chaseStack[j].ft];
2501 boards[i+1][chaseStack[j].rt][chaseStack[j].ft] = boards[i+1][chaseStack[j].rf][chaseStack[j].ff];
2502 boards[i+1][chaseStack[j].rf][chaseStack[j].ff] = EmptySquare;
2503 // Then test if the opponent can recapture
2504 cl.recaptures = 0; // prepare closure to pass recapture square and count moves to it
2505 cl.rt = chaseStack[j].rt;
2506 cl.ft = chaseStack[j].ft;
2507 if(appData.debugMode) {
2508 fprintf(debugFP, "test if we can recapture %c%c\n", cl.ft+AAA, cl.rt+ONE);
2510 xqCheckers[EP_STATUS] = 2; // causes GenLegal to ignore the checks we delivered with the move, in real life evaded before we captured
2511 GenLegal(boards[i+1], PosFlags(i+1), ProtectedCallback, &cl, EmptySquare); // try all moves
2512 xqCheckers[EP_STATUS] = 0; // disable quasi-legal moves again
2513 // unmake the capture
2514 boards[i+1][chaseStack[j].rf][chaseStack[j].ff] = boards[i+1][chaseStack[j].rt][chaseStack[j].ft];
2515 boards[i+1][chaseStack[j].rt][chaseStack[j].ft] = captured;
2516 // if a recapture was found, piece is protected, and we are not chasing it.
2517 if(cl.recaptures) { // attacked piece was defended by true protector, no chase
2518 chaseStack[j] = chaseStack[--chaseStackPointer]; // so delete from chaseStack
2522 // chaseStack now contains all moves that chased
2523 if(appData.debugMode) { int n;
2524 for(n=0; n<chaseStackPointer; n++)
2525 fprintf(debugFP, "%c%c%c%c ", chaseStack[n].ff+AAA, chaseStack[n].rf+ONE,
2526 chaseStack[n].ft+AAA, chaseStack[n].rt+ONE);
2527 fprintf(debugFP, ": chases\n");
2529 if(i == first) { // copy all people chased by first move of repeat cycle to preyStack
2530 for(j=0; j<chaseStackPointer; j++) {
2531 preyStack[j].rank = chaseStack[j].rt;
2532 preyStack[j].file = chaseStack[j].ft;
2534 preyStackPointer = chaseStackPointer;
2537 for(j=0; j<chaseStackPointer; j++) {
2538 for(k=0; k<preyStackPointer; k++) {
2539 // search the victim of each chase move on the preyStack (first occurrence)
2540 if(chaseStack[j].ft == preyStack[k].file && chaseStack[j].rt == preyStack[k].rank ) {
2541 if(k < tail) break; // piece was already identified as still being chased
2542 preyStack[preyStackPointer] = preyStack[tail]; // move chased piece to bottom part of preyStack
2543 preyStack[tail] = preyStack[k]; // by swapping
2544 preyStack[k] = preyStack[preyStackPointer];
2550 preyStackPointer = tail; // keep bottom part of preyStack, popping pieces unchased on move i.
2551 if(appData.debugMode) { int n;
2552 for(n=0; n<preyStackPointer; n++)
2553 fprintf(debugFP, "%c%c ", preyStack[n].file+AAA, preyStack[n].rank+ONE);
2554 fprintf(debugFP, "always chased upto ply %d\n", i);
2556 // now adjust the location of the chased pieces according to opponent move
2557 for(j=0; j<preyStackPointer; j++) {
2558 if(preyStack[j].rank == moveList[i+1][1]-ONE &&
2559 preyStack[j].file == moveList[i+1][0]-AAA+BOARD_LEFT) {
2560 preyStack[j].rank = moveList[i+1][3]-ONE;
2561 preyStack[j].file = moveList[i+1][2]-AAA+BOARD_LEFT;
2566 return preyStackPointer ? 256*(preyStack[preyStackPointer].file - BOARD_LEFT + AAA) + (preyStack[preyStackPointer].rank + ONE)
2567 : 0; // if any piece was left on preyStack, it has been perpetually chased,and we return the