Ratings & Comments

Yes, I originally would have thought when an Advancer made a move that threatened a King, an enforcing preset would automatically announce check.

However, maybe the Advancer, being an Ultima-like piece, does not actually make a check in an Ultima-like game (which Butterfly Chess is not)?

So I now ask, is that the usual assumption that Applet generated preset code makes for every CV put through the generating process?

I don't know how a generated preset works, but the checked subroutine I use in the fairychess include file normally checks for captures by displacement by checking if each enemy piece on the board can move to the King's position. This would not normally work with Ultima pieces, which do not normally capture by displacement, but I have managed to use this subroutine with Ultima without modifying it. First, let's look at the subroutine:

sub checked king:
    my from piece;
    local movetype;

    set movetype CHECK;
    if isupper cond empty var king $moved space var king:
        def enemies onlylower;
    else:
        def enemies onlyupper;
    endif;
    for (from piece) fn enemies:
        if fn const alias #piece #from var king:
            return #from;
        endif;
    next;
    return false;
endsub;

The key to working with Ultima is that it sets movetype to CHECK. With this in mind, I have written functions for Ultima pieces like this:

def Black_Withdrawer fn join "Black_Withdrawer_" var movetype #0 #1;

Depending upon the value of movetype, it will call either Black_Withdrawer_MOVE or Black_Withdrawer_CHECK, which I have defined separately and differently. Thanks to setting movetype to CHECK, the checked subroutine will use the *_CHECK functions for Ultima pieces. Instead of going through a normal move, one of these functions will check whether the piece at the first coordinate can capture the piece at the second. For example:

def Black_Withdrawer_CHECK 
empty where #frm - file #frm file #to - rank #frm rank #to
and == distance #frm #to 1
and not near #frm I 1
=frm =to;

This first makes sure that the piece is not next to a White Immobilizer (designated as I). It then verifies that the two spaces are adjacent. Calculating the direction away from the piece at #to, it checks whether there is an adjacent empty space in that direction. If there is, it returns true.

@ H.G.:

Yes, I originally would have thought when an Advancer made a move that threatened a King, an enforcing preset would automatically announce check.

However, maybe the Advancer, being an Ultima-like piece, does not actually make a check in an Ultima-like game (which Butterfly Chess is not)? So I now ask, is that the usual assumption that Applet generated preset code makes for every CV put through the generating process? If so, maybe an option can be added to the Applet to ask if Ultima-like pieces should announce check.

A problem for Butterfly Chess, anyway, is that if check is not announced for Advancers, what happens if the opponent's next move leaves his king vulnerable to capture by the Advancer. Does the preset announce the opponent made an illegal move (my much preferred choice, implicit in Butterfly Chess rules), or can the king be captured (if so, is a win announced, or does a player type in 'won' after his K-capturing Advancer move is manually entered, or does he tell his opponent to make a legal move instead)?

Yea, Interactive Diagrams on this site already do that by the way)

Loop Chess, watch in What’s New.

Cold mountain by DgamerA

Well, for names, since the Bishops are also slow checkmaters, I'd give them names to fit: Conway and Buzzi (it doesn't matter which is which). The Rooks are fine as Trumpets, but I'd go with Left and Right. Ranged Oyster would seem better as Giant Oyster (I do like the Oyster part).

As for icons, the Sloth and Turtle would be the Aardvark and Turtle (respectively) with the Three in front. The Conway and Buzzi could be Abbot and Abbess, either alone or with the Confused emoticon, Grey color, or Hourglass behind. The Trumpets are probably fine as they are (at least until I can figure out and upload a Trumpet icon for the set). A Giant Oyster could be what you use, or perhaps Malkia or Kuhani with the Large modifier.

(I'd do some experimenting to see which of these icons would look best, but I have a few other things going on today, and my brain isn't quite firing on all cylinders.)

Yesterday was such a weird day that I forgot to post the PotD, even though by the end of the day I thought I'd done it. So...

295. Quarterback. Expanding on my set of pieces with an American Football theme, the Quarterback is probably the most complex of the lot.

The piece's basic move is to any space within a two-square range, but without leaping.

It also has two options for an initial move. The first is to "jump" the front line: it can leap two spaces in any direction forward; or it can leap over any piece in one of the three spaces directly in front of it to the second space beyond that, without capture.*

The other option for an initial move is the chess equivalent of a pass: the Quarterback swaps places with any friendly piece on the board. (K2nNifhSiffNipfampfamfhKipfampfhamfKimpfapsampz(vs)amfWimpfapsampszafsmWiudU)**

At first I thought I'd need to adjust this piece and make the stars smaller, but once it rendered fully I decided that that would be unnecessary.

(As for today's piece, I'll try to get that up this afternoon.)

*In the XBetza code, I'm frankly a little unsure about the part about jumping over a piece to the second beyond, even though I tested all four parts of that and they all worked as expected.

**Probably this would be much shorter with bracket notation; my brain isn't functioning right to figure it out right now, though.