Author: leonid
Date: 04:29:47 09/24/99
Go up one level in this thread
On September 23, 1999 at 23:12:48, Normand M. Blais wrote:
>On September 23, 1999 at 22:44:01, leonid wrote:
>
>>On September 23, 1999 at 14:11:57, Normand M. Blais wrote:
>>
>>>On September 22, 1999 at 15:30:36, Brian Nielsen wrote:
>>>
>>>>
>>>>Hi
>>>>
>>>>My name is Brian, i was thinking about writing a chess engine for fun.
>>>>I am pretty experienced programmer/developper(c++,delpie), but have not been
>>>>programming games, thoug i have made a packman clone a couple years ago.
>>>>
>>>>I have done a little research myself to get the principles in making a chess
>>>>engine/program, and i think i now have basic understanding in how to(i hope :-))
>>>>
>>>>i am curious in how you chessgame programmers represent the chessboard, I have
>>>>seen 4-5 different examples/ways in how to do it, how do you do it and why ??
>>>>
>>>>Second how long time does it take to make a basic engine! from scratch
>>>>provided that i am a experienced programmer.
>>>>
>>>>Best regards
>>>>
>>>>Brian Nielsen
>>>
>>>
>>>Hi,
>>>
>>>I'm not using C/C++ (yet) but I thought I could share the idea that I use for
>>>my chess program. It is probably not new but I've nerver seen it mentionned any-
>>>where. It is easy to understand and to implement. So, just for the record, here
>>>it is.
>>>
>>>
>>>
>>>preliminary notes: The lower bound for array indexing is 1 (not 0) in the
>>> explanation below.
>>>
>>>1- The board is represented by an array of 64 integers.
>>>
>>>
>>>
>>> 1 2 3 4 5 6 7 8 - 8
>>> 9 10 11 12 13 14 15 16 - 7
>>> 17 18 19 20 21 22 23 24 - 6
>>> 25 26 27 28 29 30 31 32 - 5
>>> 33 34 35 36 37 38 39 40 - 4
>>> 41 42 43 44 45 46 47 48 - 3
>>> 49 50 51 52 53 54 55 56 - 2
>>> 57 58 59 60 61 62 63 64 - 1
>>>
>>> A B C D E F G H
>>>
>>>
>>>2- A 64 by 8 integer array is used for the piece movements. For each square,
>>> 8 directions is recorded:
>>>
>>>
>>> NW(8) N(1) NE(2)
>>> \ | /
>>> W(7)--- ----E(3)
>>> / | \
>>> SW(6) S(5) SE(4)
>>>
>>> For a given square and a given direction, the index of the adjacent square
>>> is stored. If there is no square (case of a border square), 0 is stored.
>>>
>>> directions: 1 2 3 4 5 6 7 8
>>> ---------------------------------------
>>> square(1) = 0, 0, 2,10, 9, 0, 0, 0
>>> square(2) = 0, 0, 3,11,10, 9, 1, 0
>>> .
>>> .
>>> .
>>> square(64) = 56, 0, 0, 0, 0, 0,63,55
>>>
>>>
>>>3- The movement of the pieces are defined in term of directions:
>>>
>>> Rook --> 1 to 7 by 2
>>> Bishop --> 2 to 8 by 2
>>> Queen --> 1 to 8 by 1
>>> King --> 1 to 8 by 1
>>>
>>> Knight --> {1,1,2},{1,1,8},{3,3,2},{3,3,4},
>>> {5,5,4},{5,5,6},{7,7,6},{7,7,8}
>>> White:
>>> pawn move one --> 1
>>> pawn move two --> {1,1}
>>> pawn captures --> 2,8
>>>
>>> Black:
>>> pawn move one --> 5
>>> pawn move two --> {5,5}
>>> pawn captures --> 4,6
>>>
>>>4- Enhencements.
>>>
>>> A 64 by 8 array can be generated for the knight where the squares stored
>>> for a given direction is the end square of a knight move. Then the knight
>>> movement can be defined this way:
>>>
>>> Knight --> 1 to 8 by 1
>>>
>>>
>>>
>>>Best Regards,
>>>
>>>Normand M. Blais
>>
>>This is pretty fascinating for me to find your description of the chess
>>board. It had nothing to do with mine. My question to you is: Do your
>>representation of the board is usual?
>>
>>Thanks,
>>Leonid.
>>boad represention is usual one or something
>
>The way I represent the chess board is not new. What's particular is the way I
>generate the moves using an intermediary array to represent directions. I was
>able to build a movegenerator in a short time. I compare it to TSCP move
>generator and it is as fast if not faster. I know that the bitboard is the way
>to go but I'm using an interpreted language that don't have 64bits unsigned
>integer data type. I'm programming for fun only.
>
>NMB
Now I see why I found your way so new. I am programming also for fun even
if all the time some fantazy is there to overrun my commun sense. In dreamy
state I see my logic taking over the World. I believe it is standart dream
for every programmer.
I would like to ask you if somehow your way to programm is already on the
Web. Never mind if your way is not so speedy in your code. Speed could
be nothing more that the way the idea was implemented.
All the best for your programming,
Leonid.
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