Allow definition of castling in piece command

[xboard.git] / moves.c

diff --git a/moves.c b/moves.c
index 9700dbf..e3afe36 100644 (file)
--- a/moves.c
+++ b/moves.c
@@ -256,6 +256,9 @@ MovesFromString (Board board, int flags, int f, int r, char *desc, MoveCallback
        if(expo > 9) p++;                             // allow double-digit
        desc = p;                                     // this is start of next move
        if(initial && board[r][f] != initialPosition[r][f]) continue;
+       if(expo > 1 && dx == 0 && dy == 0) {          // castling indicated by O + number
+           mode |= 16; dy = 1;
+       }
         do {
          for(dir=0, bit=1; dir<8; dir++, bit += bit) { // loop over directions
            int i = expo, vx, vy;
@@ -274,6 +277,15 @@ MovesFromString (Board board, int flags, int f, int r, char *desc, MoveCallback
                if(mode & 8 && y == board[EP_RANK] && occup == 4 && board[EP_FILE] == x) { // to e.p. square
                    cb(board, flags, mine == 1 ? WhiteCapturesEnPassant : BlackCapturesEnPassant, r, f, y, x, cl);
                }
+               if(mode & 16) {              // castling
+                   i = 2;                   // kludge to elongate move indefinitely
+                   if(occup == 4) continue; // skip empty squares
+                   if(x == BOARD_LEFT   && board[y][x] == initialPosition[y][x]) // reached initial corner piece
+                       cb(board, flags, mine == 1 ? WhiteQueenSideCastle : BlackQueenSideCastle, r, f, y, f - expo, cl);
+                   if(x == BOARD_RGHT-1 && board[y][x] == initialPosition[y][x])
+                       cb(board, flags, mine == 1 ? WhiteKingSideCastle : BlackKingSideCastle, r, f, y, f + expo, cl);
+                   break;
+               }
                if(occup & mode) cb(board, flags, NormalMove, r, f, y, x, cl); // allowed, generate
                if(occup != 4) break; // not valid transit square
            } while(--i);
@@ -1218,6 +1230,7 @@ GenLegal (Board board, int  flags, MoveCallback callback, VOIDSTAR closure, Ches
     int ignoreCheck = (flags & F_IGNORE_CHECK) != 0;
     ChessSquare wKing = WhiteKing, bKing = BlackKing, *castlingRights = board[CASTLING];
     int inCheck = !ignoreCheck && CheckTest(board, flags, -1, -1, -1, -1, FALSE); // kludge alert: this would mark pre-existing checkers if status==1
+    char *p;
 
     cl.cb = callback;
     cl.cl = closure;
@@ -1232,6 +1245,9 @@ GenLegal (Board board, int  flags, MoveCallback callback, VOIDSTAR closure, Ches
         wKing = WhiteUnicorn; bKing = BlackUnicorn;
     }
 
+    p = (flags & F_WHITE_ON_MOVE ? pieceDesc[wKing] : pieceDesc[bKing]);
+    if(p && strchr(p, 'O')) return FALSE; // [HGM] gen: castlings were already generated from string
+
     for (ff = BOARD_WIDTH>>1; ff >= (BOARD_WIDTH-1)>>1; ff-- /*ics wild 1*/) {
        if ((flags & F_WHITE_ON_MOVE) &&
            (flags & F_WHITE_KCASTLE_OK) &&