2 * moves.h - Move generation and checking
3 * $Id: moves.h,v 2.1 2003/10/27 19:21:00 mann Exp $
5 * Copyright 1991 by Digital Equipment Corporation, Maynard, Massachusetts.
6 * Enhancements Copyright 1992-95 Free Software Foundation, Inc.
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49 extern ChessSquare PromoPiece P((ChessMove moveType));
50 extern ChessMove PromoCharToMoveType P((int whiteOnMove, int promoChar));
51 extern char PieceToChar P((ChessSquare p));
52 extern ChessSquare CharToPiece P((int c));
53 extern int PieceToNumber P((ChessSquare p));
55 extern void CopyBoard P((Board to, Board from));
56 extern int CompareBoards P((Board board1, Board board2));
57 extern char pieceToChar[(int)EmptySquare+1];
59 typedef void (*MoveCallback) P((Board board, int flags, ChessMove kind,
60 int rf, int ff, int rt, int ft,
63 /* Values for flags arguments */
64 #define F_WHITE_ON_MOVE 1
65 #define F_WHITE_KCASTLE_OK 2
66 #define F_WHITE_QCASTLE_OK 4
67 #define F_BLACK_KCASTLE_OK 8
68 #define F_BLACK_QCASTLE_OK 16
69 #define F_ALL_CASTLE_OK (F_WHITE_KCASTLE_OK | F_WHITE_QCASTLE_OK | \
70 F_BLACK_KCASTLE_OK | F_BLACK_QCASTLE_OK)
71 #define F_IGNORE_CHECK 32
72 #define F_KRIEGSPIEL_CAPTURE 64 /* pawns can try to capture invisible pieces */
73 #define F_ATOMIC_CAPTURE 128 /* capturing piece explodes, destroying itself
74 and all non-pawns on adjacent squares;
75 destroying your own king is illegal */
76 #define F_FRC_TYPE_CASTLING 256 /* generate castlings as captures of own Rook */
78 /* Special epfile values. [HGM] positive values are non-reversible moves! */
79 #define EP_NONE (-4) /* [HGM] Tricky! order matters: */
80 #define EP_UNKNOWN (-1) /* >= EP_UNKNOWN spils rep-draw */
81 #define EP_CAPTURE (-2) /* <= EP_NONE is reversible move */
82 #define EP_PAWN_MOVE (-3)
83 #define EP_REP_DRAW (-15)
84 #define EP_RULE_DRAW (-14)
85 #define EP_INSUF_DRAW (-13)
86 #define EP_DRAWS (-10)
87 #define EP_BEROLIN_A 16 /* [HGM] berolina: add to file if pawn to be taken of a-side of e.p.file */
88 #define EP_CHECKMATE 100 /* [HGM] verify: record mates in epStatus for easy claim verification */
89 #define EP_STALEMATE -16
91 /* Call callback once for each pseudo-legal move in the given
92 position, except castling moves. A move is pseudo-legal if it is
93 legal, or if it would be legal except that it leaves the king in
94 check. In the arguments, epfile is EP_NONE if the previous move
95 was not a double pawn push, or the file 0..7 if it was, or
96 EP_UNKNOWN if we don't know and want to allow all e.p. captures.
97 Promotion moves generated are to Queen only.
99 extern void GenPseudoLegal P((Board board, int flags, int epfile,
100 MoveCallback callback, VOIDSTAR closure));
102 /* Like GenPseudoLegal, but include castling moves and (unless
103 F_IGNORE_CHECK is set in the flags) omit moves that would leave the
104 king in check. The CASTLE_OK flags are true if castling is not yet
105 ruled out by a move of the king or rook. Return TRUE if the player
106 on move is currently in check and F_IGNORE_CHECK is not set.
108 extern int GenLegal P((Board board, int flags, int epfile,
109 char castlingRights[], /* [HGM] */
110 MoveCallback callback, VOIDSTAR closure));
112 /* If the player on move were to move from (rf, ff) to (rt, ft), would
113 he leave himself in check? Or if rf == -1, is the player on move
114 in check now? enPassant must be TRUE if the indicated move is an
115 e.p. capture. The possibility of castling out of a check along the
116 back rank is not accounted for (i.e., we still return nonzero), as
117 this is illegal anyway. Return value is the number of times the
119 extern int CheckTest P((Board board, int flags,
120 int rf, int ff, int rt, int ft, int enPassant));
122 /* Is a move from (rf, ff) to (rt, ft) legal for the player whom the
123 flags say is on move? Other arguments as in GenPseudoLegal.
124 Returns the type of move made, taking promoChar into account. */
125 extern ChessMove LegalityTest P((Board board, int flags, int epfile,
126 char castlingRights[], /* [HGM] */
127 int rf, int ff, int rt, int ft,
132 #define MT_CHECKMATE 2
133 #define MT_STALEMATE 3
135 /* Return MT_NONE, MT_CHECK, MT_CHECKMATE, or MT_STALEMATE */
136 extern int MateTest P((Board board, int flags, int epfile,
137 char castlingRights[])); /* [HGM] */
141 ChessSquare pieceIn; /* EmptySquare if unknown */
142 int rfIn, ffIn, rtIn, ftIn; /* -1 if unknown */
143 int promoCharIn; /* NULLCHAR if unknown */
144 /* Output data for matched move */
148 int promoChar; /* 'q' if a promotion and promoCharIn was NULLCHAR */
149 int count; /* Number of possibilities found */
150 } DisambiguateClosure;
152 /* Disambiguate a partially-known move */
153 void Disambiguate P((Board board, int flags, int epfile,
154 DisambiguateClosure *closure));
157 /* Convert coordinates to normal algebraic notation.
158 promoChar must be NULLCHAR or '.' if not a promotion.
160 ChessMove CoordsToAlgebraic P((Board board, int flags, int epfile,
161 int rf, int ff, int rt, int ft,
162 int promoChar, char out[MOVE_LEN]));