| Author |
Message |
Mohamed El Mokhtar Messaoudi (Dumberbytheminute)
New member
Username: Dumberbytheminute
Post Number: 8
Registered: 11-2008
| | Posted on Wednesday, December 16, 2009 - 3:23 pm: | |
Hi all.
What would be the simplest code for a piece A to slide freely, and if bumping into an enemy piece B, to replace it with a piece C while putting an enemy piece D on the starting cell?
(My head is dizzy with from, to, add-copy, cascade and what not. Please help. Thanks.) |
M Winther (Kalroten)
New member
Username: Kalroten
Post Number: 134
Registered: 1-2007
| | Posted on Sunday, December 20, 2009 - 1:44 am: | |
How about this?
(define slide-piece
($1 (while empty? add $1)
(if not-friend?
(if (not-piece? piece-B) add
else
cascade
(change-type piece-C)
back
(create piece-D)
flip
add
)
)
)) |
Mohamed El Mokhtar Messaoudi (Dumberbytheminute)
New member
Username: Dumberbytheminute
Post Number: 9
Registered: 11-2008
| | Posted on Sunday, December 20, 2009 - 3:33 am: | |
Simple and to the point. Thanks, Mats.
Unless I am abusing, could you tell me how to do random promotions in Chess (a pawn could promote to any piece of EITHER camp)? |
M Winther (Kalroten)
New member
Username: Kalroten
Post Number: 135
Registered: 1-2007
| | Posted on Sunday, December 20, 2009 - 5:40 am: | |
I don't know if it's possible to implement random pawn promotion. But
the following code could work. The random promotion move occurs first,
at each move (move-order: random White move; normal White move; random Black move; normal Black move). If no pawn promotion is possible, then the same player moves again, and makes a normal move.
However, if a pawn exists on the seventh rank, then the random
procedure should also allow that the pawn is *not* promoted. That's
why I have inserted ((verify (not-on-board? n) add) as a random
alternative.
The problem is that if a random promotion has occurred, then the
player should not be allowed to move again. How to prevent this? One
would have to verify before each move that a promotion has not
occurred. One can check last-to and see whether this a friendly piece.
Then a promotion has ocurred if it's positioned on the last rank.
The code should look something like this:
(players White Black ?Random1 ?Random2)
(turn-order
(?Random1 White promotiontype)
White
(?Random2 Black promotiontype)
Black
)
(define Pawn-move-promotion1
(
(verify (not-on-board? n)
(add Bishop Knight Queen Rook)
add
)
)
(define Pawn-move-promotion2 ;this promotes to enemy piece
(
(verify (not-on-board? n)
(add Bishop Knight Queen Rook)
flip
add
)
)
(piece (name Pawn)
(moves
(move-type promotiontype)
(Pawn-move-promotion1)
(Pawn-move-promotion2)
((verify (not-on-board? n) add)
(...insert code for pawn movement and capture with promotion
removed)
))
/Mats |
Mohamed El Mokhtar Messaoudi (Dumberbytheminute)
New member
Username: Dumberbytheminute
Post Number: 10
Registered: 11-2008
| | Posted on Sunday, December 20, 2009 - 2:20 pm: | |
Thanks again for bearing with me, mats. I will try to extricate all this. Your idea seems simpler than the scheme I had devised:
An off-board zone (with suitable links) to be half-filled up in the first turn by a player (by some method- deterministic of course), then by the second player in the second turn, by standard promotion macros. The game proceeds normally from then on.
Whenever a promotion occurs during the game, a piece is fetched and brought up from the off-board zone, and put into play.
The glitch would then lie in the fact that if one knows about the method, he could predict the color of the n-th promotion, though not the piece type. (bearing in mind that a promoted piece can equally turn up to be Black or White, whatever the camp currently moving.) |
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