diff options
Diffstat (limited to 'chess-pos.el')
| -rw-r--r-- | chess-pos.el | 57 |
1 files changed, 25 insertions, 32 deletions
diff --git a/chess-pos.el b/chess-pos.el index f326c09..7249399 100644 --- a/chess-pos.el +++ b/chess-pos.el @@ -281,9 +281,7 @@ trying to move a blank square." (unless (symbolp (car changes)) (let ((piece (downcase (chess-pos-piece position (cadr changes))))) (cond - ((and (= piece ?k) - (equal (car changes) - (chess-rf-to-index (if color 7 0) 4))) + ((= piece ?k) (chess-pos-set-can-castle position (if color ?K ?k) nil) (chess-pos-set-can-castle position (if color ?Q ?q) nil)) @@ -380,8 +378,9 @@ indices which indicate where a piece may have moved from." (if (setq pos (chess-add-index target (- bias) 0)) (if (chess-pos-piece-p position pos piece) (setq candidates (list pos)) - (when (and (= ? (chess-pos-piece position pos)) - (= (if color 4 3) (chess-index-rank target))) + (when (and (chess-pos-piece-p position pos ? ) + (= (if color 4 3) + (chess-index-rank target))) (setq pos (chess-add-index pos (- bias) 0)) (if (and pos (chess-pos-piece-p position pos piece)) (setq candidates (list pos))))))))) @@ -410,7 +409,7 @@ indices which indicate where a piece may have moved from." (progn (nconc candidates (list pos)) (setq pos nil)) - (if (/= (chess-pos-piece position pos) ? ) + (if (not (chess-pos-piece-p position pos ? )) (setq pos nil) (setq pos (apply 'chess-add-index pos dir)))))) (setq candidates (cdr candidates))) @@ -430,32 +429,26 @@ indices which indicate where a piece may have moved from." ;; if we can still castle, then the king and rook are in their ;; squares; also, make sure that the user is not attempting to ;; castle through check - (if (and - (null candidates) - (or (and (equal target (chess-rf-to-index rank 6)) - (= (chess-pos-piece position (chess-rf-to-index rank 4)) - (if color ?K ?k)) - (chess-pos-can-castle position (if color ?K ?k)) - (setq pos (chess-rf-to-index rank 5)) - (chess-pos-piece-p position pos ? ) - (not (chess-search-position position pos (not color))) - (setq pos (chess-rf-to-index rank 6)) - (chess-pos-piece-p position pos ? ) - (not (chess-search-position position pos (not color)))) - (and (equal target (chess-rf-to-index rank 2)) - (= (chess-pos-piece position (chess-rf-to-index rank 4)) - (if color ?K ?k)) - (chess-pos-can-castle position (if color ?Q ?q)) - (setq pos (chess-rf-to-index rank 1)) - (chess-pos-piece-p position pos ? ) - (not (chess-search-position position pos (not color))) - (setq pos (chess-rf-to-index rank 2)) - (chess-pos-piece-p position pos ? ) - (not (chess-search-position position pos (not color))) - (setq pos (chess-rf-to-index rank 3)) - (chess-pos-piece-p position pos ? ) - (not (chess-search-position position pos (not color)))))) - (setq candidates (list (chess-rf-to-index rank 4)))))) + (if (and (null candidates) + (or (and (equal target (chess-rf-to-index rank 6)) + (chess-pos-can-castle position (if color ?K ?k))) + (and (equal target (chess-rf-to-index rank 2)) + (chess-pos-can-castle position (if color ?Q ?q))))) + (let* ((king (car (chess-pos-search position piece))) + (king-file (chess-index-file king)) + (long (= 2 (chess-index-file target))) + (file (if long 1 6)) + (legal t)) + ;; jww (2002-04-10): this needs to be a bit more subtle + ;; for Fischer Random castling + (while (and legal (funcall (if long '< '>) file king-file)) + (setq pos (chess-rf-to-index rank file)) + (if (or (not (chess-pos-piece-p position pos ? )) + (chess-search-position position pos (not color))) + (setq legal nil) + (setq file (funcall (if long '1+ '1-) file)))) + (if legal + (setq candidates (list (chess-rf-to-index rank 4)))))))) ;; the knight is a zesty little piece; there may be more than ;; one, but at only one possible square in each direction |