/*
* moves.c - Move generation and checking
- * $Id: moves.c,v 2.1 2003/10/27 19:21:00 mann Exp $
*
* Copyright 1991 by Digital Equipment Corporation, Maynard,
- * Massachusetts. Enhancements Copyright
- * 1992-2001,2002,2003,2004,2005,2006,2007,2008,2009 Free Software
- * Foundation, Inc.
+ * Massachusetts.
+ *
+ * Enhancements Copyright 1992-2001, 2002, 2003, 2004, 2005, 2006,
+ * 2007, 2008, 2009 Free Software Foundation, Inc.
+ *
+ * Enhancements Copyright 2005 Alessandro Scotti
*
* The following terms apply to Digital Equipment Corporation's copyright
* interest in XBoard:
int WhitePiece P((ChessSquare));
int BlackPiece P((ChessSquare));
int SameColor P((ChessSquare, ChessSquare));
+int PosFlags(int index);
-extern char initialRights[BOARD_SIZE]; /* [HGM] all rights enabled, set in InitPosition */
+extern signed char initialRights[BOARD_SIZE]; /* [HGM] all rights enabled, set in InitPosition */
int WhitePiece(piece)
char pieceToChar[] = {
'P', 'N', 'B', 'R', 'Q', 'F', 'E', 'A', 'C', 'W', 'M',
- 'O', 'H', 'I', 'J', 'G', 'D', 'V', 'L', 's', 'U', 'K',
+ 'O', 'H', 'I', 'J', 'G', 'D', 'V', 'L', 'S', 'U', 'K',
'p', 'n', 'b', 'r', 'q', 'f', 'e', 'a', 'c', 'w', 'm',
'o', 'h', 'i', 'j', 'g', 'd', 'v', 'l', 's', 'u', 'k',
'x' };
if (board[rt][ft] != EmptySquare) break;
}
if(m==1) goto mounted;
- if(m==2) goto finishGold;
+ if(m==2) goto finishSilver;
break;
case WhiteQueen:
case SHOGI BlackKing:
case WhiteKing:
case BlackKing:
- walking:
+// walking:
for (i = -1; i <= 1; i++)
for (j = -1; j <= 1; j++) {
if (i == 0 && j == 0) continue;
}
}
break;
+ case WhiteFalcon: // [HGM] wild: for wildcards, self-capture symbolizes move to anywhere
+ case BlackFalcon:
+ case WhiteCobra:
+ case BlackCobra:
+ case WhiteLance:
+ case BlackLance:
+ callback(board, flags, NormalMove, rf, ff, rf, ff, closure);
+ break;
}
}
typedef struct {
int rf, ff, rt, ft;
ChessMove kind;
+ int captures; // [HGM] losers
} LegalityTestClosure;
}
}
- return cl.check;
+ return cl.fking < BOARD_RGHT ? cl.check : 1000; // [HGM] atomic: return 1000 if we have no king
}
// if (appData.debugMode) {
// fprintf(debugFP, "Legality test: %c%c%c%c\n", ff+AAA, rf+ONE, ft+AAA, rt+ONE);
// }
+ if(board[rt][ft] != EmptySquare || kind==WhiteCapturesEnPassant || kind==BlackCapturesEnPassant)
+ cl->captures++; // [HGM] losers: count legal captures
if (rf == cl->rf && ff == cl->ff && rt == cl->rt && ft == cl->ft)
cl->kind = kind;
}
if(piece == WhiteFalcon || piece == BlackFalcon ||
piece == WhiteCobra || piece == BlackCobra ||
piece == WhiteLance || piece == BlackLance)
- return NormalMove;
+ return CheckTest(board, flags, rf, ff, rt, ft, FALSE) ? IllegalMove : NormalMove;
cl.rf = rf;
cl.ff = ff;
cl.rt = rt;
cl.ft = ft;
cl.kind = IllegalMove;
+ cl.captures = 0; // [HGM] losers: prepare to count legal captures.
GenLegal(board, flags, epfile, castlingRights, LegalityTestCallback, (VOIDSTAR) &cl);
+ if((flags & F_MANDATORY_CAPTURE) && cl.captures && board[rt][ft] == EmptySquare
+ && cl.kind != WhiteCapturesEnPassant && cl.kind != BlackCapturesEnPassant)
+ return(IllegalMove); // [HGM] losers: if there are legal captures, non-capts are illegal
if(gameInfo.variant == VariantShogi) {
/* [HGM] Shogi promotions. '=' means defer */
char castlingRights[];
{
MateTestClosure cl;
- int inCheck;
+ int inCheck, r, f, myPieces=0, hisPieces=0, nrKing=0;
+ ChessSquare king = flags & F_WHITE_ON_MOVE ? WhiteKing : BlackKing;
+ for(r=0; r<BOARD_HEIGHT; r++) for(f=BOARD_LEFT; f<BOARD_RGHT; f++) {
+ // [HGM] losers: Count pieces and kings, to detect other unorthodox winning conditions
+ nrKing += (board[r][f] == king); // stm has king
+ if( board[r][f] != EmptySquare ) {
+ if((int)board[r][f] <= (int)king && (int)board[r][f] >= (int)king - (int)WhiteKing + (int)WhitePawn)
+ myPieces++;
+ else hisPieces++;
+ }
+ }
+ if(appData.debugMode) fprintf(debugFP, "MateTest: K=%d, my=%d, his=%d\n", nrKing, myPieces, hisPieces);
+ switch(gameInfo.variant) { // [HGM] losers: extinction wins
+ case VariantShatranj:
+ if(hisPieces == 1) return myPieces > 1 ? MT_BARE : MT_DRAW;
+ default:
+ break;
+ case VariantAtomic:
+ if(nrKing == 0) return MT_NOKING;
+ break;
+ case VariantLosers:
+ if(myPieces == 1) return MT_BARE;
+ }
cl.count = 0;
inCheck = GenLegal(board, flags, epfile, castlingRights, MateTestCallback, (VOIDSTAR) &cl);
+ // [HGM] 3check: yet to do!
if (cl.count > 0) {
return inCheck ? MT_CHECK : MT_NONE;
} else {
- return inCheck || gameInfo.variant == VariantXiangqi || gameInfo.variant == VariantShatranj ?
- MT_CHECKMATE : MT_STALEMATE;
+ if(gameInfo.variant == VariantSuicide) // [HGM] losers: always stalemate, since no check, but result varies
+ return myPieces == hisPieces ? MT_STALEMATE :
+ myPieces > hisPieces ? MT_STAINMATE : MT_STEALMATE;
+ else if(gameInfo.variant == VariantLosers) return inCheck ? MT_TRICKMATE : MT_STEALMATE;
+ else if(gameInfo.variant == VariantGiveaway) return MT_STEALMATE; // no check exists, stalemated = win
+
+ return inCheck ? MT_CHECKMATE
+ : (gameInfo.variant == VariantXiangqi || gameInfo.variant == VariantShatranj) ?
+ MT_STAINMATE : MT_STALEMATE;
}
}
VOIDSTAR closure;
{
register DisambiguateClosure *cl = (DisambiguateClosure *) closure;
+ int wildCard = FALSE; ChessSquare piece = board[rf][ff];
+
+ // [HGM] wild: for wild-card pieces rt and rf are dummies
+ if(piece == WhiteFalcon || piece == BlackFalcon ||
+ piece == WhiteCobra || piece == BlackCobra ||
+ piece == WhiteLance || piece == BlackLance)
+ wildCard = TRUE;
if ((cl->pieceIn == EmptySquare || cl->pieceIn == board[rf][ff]
|| PieceToChar(board[rf][ff]) == '~'
) &&
(cl->rfIn == -1 || cl->rfIn == rf) &&
(cl->ffIn == -1 || cl->ffIn == ff) &&
- (cl->rtIn == -1 || cl->rtIn == rt) &&
- (cl->ftIn == -1 || cl->ftIn == ft)) {
+ (cl->rtIn == -1 || cl->rtIn == rt || wildCard) &&
+ (cl->ftIn == -1 || cl->ftIn == ft || wildCard)) {
cl->count++;
cl->piece = board[rf][ff];
cl->rf = rf;
cl->ff = ff;
- cl->rt = rt;
- cl->ft = ft;
+ cl->rt = wildCard ? cl->rtIn : rt;
+ cl->ft = wildCard ? cl->ftIn : ft;
cl->kind = kind;
}
}
DisambiguateClosure *closure;
{
int illegal = 0; char c = closure->promoCharIn;
+
closure->count = 0;
closure->rf = closure->ff = closure->rt = closure->ft = 0;
closure->kind = ImpossibleMove;
/* [HGM] Shogi promotions. '=' means defer */
if(closure->rfIn != DROP_RANK && closure->kind == NormalMove) {
ChessSquare piece = closure->piece;
-#if 0
- if (appData.debugMode) {
- fprintf(debugFP, "Disambiguate A: %d(%d,%d)-(%d,%d) = %d (%c)\n",
- closure->pieceIn,closure->ffIn,closure->rfIn,closure->ftIn,closure->rtIn,
- closure->promoCharIn,closure->promoCharIn);
- }
-#endif
if(c != NULLCHAR && c != 'x' && c != '+' && c != '=' &&
ToUpper(PieceToChar(PROMOTED piece)) != ToUpper(c) )
closure->kind = IllegalMove;
else if(flags & F_WHITE_ON_MOVE) {
-#if 0
- if (appData.debugMode) {
- fprintf(debugFP, "Disambiguate B: %d(%d,%d)-(%d,%d) = %d (%c)\n",
- closure->pieceIn,closure->ffIn,closure->rfIn,closure->ftIn,closure->rtIn,
- closure->promoCharIn,closure->promoCharIn);
- }
-#endif
if( (int) piece < (int) WhiteWazir &&
(closure->rf > BOARD_HEIGHT-4 || closure->rt > BOARD_HEIGHT-4) ) {
if( (piece == WhitePawn || piece == WhiteQueen) && closure->rt > BOARD_HEIGHT-2 ||
closure->kind = IllegalMove;
}
}
-#if 0
- if (appData.debugMode) {
- fprintf(debugFP, "Disambiguate C: %d(%d,%d)-(%d,%d) = %d (%c)\n",
- closure->pieceIn,closure->ffIn,closure->rfIn,closure->ftIn,closure->rtIn,
- closure->promoCharIn,closure->promoCharIn);
- }
-#endif
/* [HGM] returns 'q' for optional promotion, 'n' for mandatory */
if(closure->promoCharIn != '=')
closure->promoChar = ToLower(closure->promoCharIn);
return IllegalMove;
}
+// [HGM] XQ: the following code serves to detect perpetual chasing (Asian rules)
+
+typedef struct {
+ /* Input */
+ int rf, ff, rt, ft;
+ /* Output */
+ int recaptures;
+} ChaseClosure;
+
+// I guess the following variables logically belong in the closure too, but I was too lazy and used globals
+
+int preyStackPointer, chaseStackPointer;
+
+struct {
+char rf, ff, rt, ft;
+} chaseStack[100];
+
+struct {
+char rank, file;
+} preyStack[100];
+
+
+
+
+// there are three new callbacks for use with GenLegal: for adding captures, deleting them, and finding a recapture
+
+extern void AtacksCallback P((Board board, int flags, ChessMove kind,
+ int rf, int ff, int rt, int ft,
+ VOIDSTAR closure));
+
+void AttacksCallback(board, flags, kind, rf, ff, rt, ft, closure)
+ Board board;
+ int flags;
+ ChessMove kind;
+ int rf, ff, rt, ft;
+ VOIDSTAR closure;
+{ // For adding captures that can lead to chase indictment to the chaseStack
+ if(board[rt][ft] == EmptySquare) return; // non-capture
+ if(board[rt][ft] == WhitePawn && rt < BOARD_HEIGHT/2) return; // Pawn before river can be chased
+ if(board[rt][ft] == BlackPawn && rt >= BOARD_HEIGHT/2) return; // Pawn before river can be chased
+ if(board[rf][ff] == WhitePawn || board[rf][ff] == BlackPawn) return; // Pawns are allowed to chase
+ if(board[rf][ff] == WhiteWazir || board[rf][ff] == BlackWazir) return; // King is allowed to chase
+ // move cannot be excluded from being a chase trivially (based on attacker and victim); save it on chaseStack
+ chaseStack[chaseStackPointer].rf = rf;
+ chaseStack[chaseStackPointer].ff = ff;
+ chaseStack[chaseStackPointer].rt = rt;
+ chaseStack[chaseStackPointer].ft = ft;
+ chaseStackPointer++;
+}
+
+extern void ExistingAtacksCallback P((Board board, int flags, ChessMove kind,
+ int rf, int ff, int rt, int ft,
+ VOIDSTAR closure));
+
+void ExistingAttacksCallback(board, flags, kind, rf, ff, rt, ft, closure)
+ Board board;
+ int flags;
+ ChessMove kind;
+ int rf, ff, rt, ft;
+ VOIDSTAR closure;
+{ // for removing pre-exsting captures from the chaseStack, to be left with newly created ones
+ int i;
+ register ChaseClosure *cl = (ChaseClosure *) closure; //closure tells us the move played in the repeat loop
+
+ if(board[rt][ft] == EmptySquare) return; // no capture
+ if(rf == cl->rf && ff == cl->ff) { // attacks with same piece from new position are not considered new
+ rf = cl->rt; ff = cl->ft; // doctor their fromSquare so they will be recognized in chaseStack
+ }
+ // search move in chaseStack, and delete it if it occurred there (as we know now it is not a new capture)
+ for(i=0; i<chaseStackPointer; i++) {
+ if(chaseStack[i].rf == rf && chaseStack[i].ff == ff &&
+ chaseStack[i].rt == rt && chaseStack[i].ft == ft ) {
+ // move found on chaseStack, delete it by overwriting with move popped from top of chaseStack
+ chaseStack[i] = chaseStack[--chaseStackPointer];
+ break;
+ }
+ }
+}
+
+extern void ProtectedCallback P((Board board, int flags, ChessMove kind,
+ int rf, int ff, int rt, int ft,
+ VOIDSTAR closure));
+
+void ProtectedCallback(board, flags, kind, rf, ff, rt, ft, closure)
+ Board board;
+ int flags;
+ ChessMove kind;
+ int rf, ff, rt, ft;
+ VOIDSTAR closure;
+{ // for determining if a piece (given through the closure) is protected
+ register ChaseClosure *cl = (ChaseClosure *) closure; // closure tells us where to recapture
+
+ if(rt == cl->rt && ft == cl->ft) cl->recaptures++; // count legal recaptures to this square
+ if(appData.debugMode && board[rt][ft] != EmptySquare)
+ fprintf(debugFP, "try %c%c%c%c=%d\n", ff+AAA, rf+ONE,ft+AAA, rt+ONE, cl->recaptures);
+}
+
+extern char moveList[MAX_MOVES][MOVE_LEN];
+
+int PerpetualChase(int first, int last)
+{ // this routine detects if the side to move in the 'first' position is perpetually chasing (when not checking)
+ int i, j, k, tail;
+ ChaseClosure cl;
+ ChessSquare captured;
+
+ preyStackPointer = 0; // clear stack of chased pieces
+ for(i=first; i<last; i+=2) { // for all positions with same side to move
+ if(appData.debugMode) fprintf(debugFP, "judge position %i\n", i);
+ chaseStackPointer = 0; // clear stack that is going to hold possible chases
+ // determine all captures possible after the move, and put them on chaseStack
+ GenLegal(boards[i+1], PosFlags(i), EP_NONE, initialRights, AttacksCallback, &cl);
+ if(appData.debugMode) { int n;
+ for(n=0; n<chaseStackPointer; n++)
+ fprintf(debugFP, "%c%c%c%c ", chaseStack[n].ff+AAA, chaseStack[n].rf+ONE,
+ chaseStack[n].ft+AAA, chaseStack[n].rt+ONE);
+ fprintf(debugFP, ": all capts\n");
+ }
+ // determine all captures possible before the move, and delete them from chaseStack
+ cl.rf = moveList[i][1]-ONE; // prepare closure to pass move that led from i to i+1
+ cl.ff = moveList[i][0]-AAA+BOARD_LEFT;
+ cl.rt = moveList[i][3]-ONE;
+ cl.ft = moveList[i][2]-AAA+BOARD_LEFT;
+ GenLegal(boards[i], PosFlags(i), EP_NONE, initialRights, ExistingAttacksCallback, &cl);
+ if(appData.debugMode) { int n;
+ for(n=0; n<chaseStackPointer; n++)
+ fprintf(debugFP, "%c%c%c%c ", chaseStack[n].ff+AAA, chaseStack[n].rf+ONE,
+ chaseStack[n].ft+AAA, chaseStack[n].rt+ONE);
+ fprintf(debugFP, ": new capts after %c%c%c%c\n", cl.ff+AAA, cl.rf+ONE, cl.ft+AAA, cl.rt+ONE);
+ }
+ // chaseSack now contains all captures made possible by the move
+ for(j=0; j<chaseStackPointer; j++) { // run through chaseStack to identify true chases
+ int attacker = (int)boards[i+1][chaseStack[j].rf][chaseStack[j].ff];
+ int victim = (int)boards[i+1][chaseStack[j].rt][chaseStack[j].ft];
+
+ if(attacker >= (int) BlackPawn) attacker = BLACK_TO_WHITE attacker; // convert to white, as piecee type
+ if(victim >= (int) BlackPawn) victim = BLACK_TO_WHITE victim;
+
+ if((attacker == WhiteKnight || attacker == WhiteCannon) && victim == WhiteRook)
+ continue; // C or H attack on R is always chase; leave on chaseStack
+
+ if(attacker == victim) {
+ if(LegalityTest(boards[i+1], PosFlags(i+1), EP_NONE, initialRights, chaseStack[j].rt,
+ chaseStack[j].ft, chaseStack[j].rf, chaseStack[j].ff, NULLCHAR) == NormalMove) {
+ // we can capture back with equal piece, so this is no chase but a sacrifice
+ chaseStack[j] = chaseStack[--chaseStackPointer]; // delete the capture from the chaseStack
+ j--; /* ! */ continue;
+ }
+ }
+
+ // the attack is on a lower piece, or on a pinned or blocked equal one
+ // test if the victim is protected by a true protector. First make the capture.
+ captured = boards[i+1][chaseStack[j].rt][chaseStack[j].ft];
+ boards[i+1][chaseStack[j].rt][chaseStack[j].ft] = boards[i+1][chaseStack[j].rf][chaseStack[j].ff];
+ boards[i+1][chaseStack[j].rf][chaseStack[j].ff] = EmptySquare;
+ // Then test if the opponent can recapture
+ cl.recaptures = 0; // prepare closure to pass recapture square and count moves to it
+ cl.rt = chaseStack[j].rt;
+ cl.ft = chaseStack[j].ft;
+ if(appData.debugMode) {
+ fprintf(debugFP, "test if we can recapture %c%c\n", cl.ft+AAA, cl.rt+ONE);
+ }
+ GenLegal(boards[i+1], PosFlags(i+1), EP_NONE, initialRights, ProtectedCallback, &cl); // try all moves
+ // unmake the capture
+ boards[i+1][chaseStack[j].rf][chaseStack[j].ff] = boards[i+1][chaseStack[j].rt][chaseStack[j].ft];
+ boards[i+1][chaseStack[j].rt][chaseStack[j].ft] = captured;
+ // if a recapture was found, piece is protected, and we are not chasing it.
+ if(cl.recaptures) { // attacked piece was defended by true protector, no chase
+ chaseStack[j] = chaseStack[--chaseStackPointer]; // so delete from chaseStack
+ j--; /* ! */
+ }
+ }
+ // chaseStack now contains all moves that chased
+ if(appData.debugMode) { int n;
+ for(n=0; n<chaseStackPointer; n++)
+ fprintf(debugFP, "%c%c%c%c ", chaseStack[n].ff+AAA, chaseStack[n].rf+ONE,
+ chaseStack[n].ft+AAA, chaseStack[n].rt+ONE);
+ fprintf(debugFP, ": chases\n");
+ }
+ if(i == first) { // copy all people chased by first move of repeat cycle to preyStack
+ for(j=0; j<chaseStackPointer; j++) {
+ preyStack[j].rank = chaseStack[j].rt;
+ preyStack[j].file = chaseStack[j].ft;
+ }
+ preyStackPointer = chaseStackPointer;
+ }
+ tail = 0;
+ for(j=0; j<chaseStackPointer; j++) {
+ for(k=0; k<preyStackPointer; k++) {
+ // search the victim of each chase move on the preyStack (first occurrence)
+ if(chaseStack[j].ft == preyStack[k].file && chaseStack[j].rt == preyStack[k].rank ) {
+ if(k < tail) break; // piece was already identified as still being chased
+ preyStack[preyStackPointer] = preyStack[tail]; // move chased piece to bottom part of preyStack
+ preyStack[tail] = preyStack[k]; // by swapping
+ preyStack[k] = preyStack[preyStackPointer];
+ tail++;
+ break;
+ }
+ }
+ }
+ preyStackPointer = tail; // keep bottom part of preyStack, popping pieces unchased on move i.
+ if(appData.debugMode) { int n;
+ for(n=0; n<preyStackPointer; n++)
+ fprintf(debugFP, "%c%c ", preyStack[n].file+AAA, preyStack[n].rank+ONE);
+ fprintf(debugFP, "always chased upto ply %d\n", i);
+ }
+ // now adjust the location of the chased pieces according to opponent move
+ for(j=0; j<preyStackPointer; j++) {
+ if(preyStack[j].rank == moveList[i+1][1]-ONE &&
+ preyStack[j].file == moveList[i+1][0]-AAA+BOARD_LEFT) {
+ preyStack[j].rank = moveList[i+1][3]-ONE;
+ preyStack[j].file = moveList[i+1][2]-AAA+BOARD_LEFT;
+ break;
+ }
+ }
+ }
+ return preyStackPointer; // if any piece was left on preyStack, it has been perpetually chased
+}
projects / xboard.git / blobdiff