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Xorix Shogi. Shogi where piece movement are XORed with captured pieces. (9x9, Cells: 81) [All Comments] [Add Comment or Rating]

🕸Fergus Duniho wrote on Sat, Jan 21, 2006 04:26 PM UTC:

Shortly after waking up this morning, I realized how to program this game
for Game Courier. If it represents each piece by a number, it can XOR the
numbers together to determine what a piece changes to when it captures
another piece.  Also, instead of writing separate movement functions for
each piece, I can write a single subroutine, or maybe a function, that
handles all non-royal piece movement by checking the bits in the numbers
representing the pieces. Given this, the first thing to start with is to
identify the basic types of movement in this game. Each basic type of
movement is the largest group of possible moves that will always be found
together. More succinctly, what are the largest indivisible sets of moves
in this game? Here's what I identify.

Forward Vertical Leap

Horizontal or Backward Vertical Leaps
Forward Diagonal Leaps
Backward Diagonal Leaps

Forward Vertical Ride of 2+ spaces
Horizontal or Backward Vertical Rides of 2+ spaces
Diagonal Rides of 2+ spaces

Forward Knight Leaps

Since every piece can leap one space vertically forward, the forward
vertical leap doesn't have to be identified by a bit. Seven sets remain,
giving a total of 128 possible pieces. I have separated these into three
groups. There is a group for one space leaps, a group for riding moves,
and a group for Knight leaps. This is to accomodate octal representation
of the piece numbers. Base 8 has the advantage over base 10 of every digit
always having the same meaning in the same place. It shares this advantage
with base 2 and base 16, but it strikes a better balance than either of
these between being easy to decode (as base 2 is) and being easy to
identify (as base 16 is). The computer doesn't care what base the pieces
are represented in, but using octal numbers will better enable humans to
use the numbers as mnemonics for remembering how pieces move. Accordingly,
each piece would get an octal number, ranging from 0 for a Pawn to 177 for
a piece that can move as a Queen or a Shogi Knight. The usual Shogi pieces
would be Pawn 0, Lance 10, Knight 100, Silver General 6, Gold General 3,
Bishop 46, and Rook 33.