6 ms·

I Made a Chess Library in Java

62 points by jaeheonshim 7y ago

suyash 7y ago
Awesome, I would encourage turn this into a actual chess game using JavaFX.
- jaeheonshim 7y ago
  That's a great idea, I'm going to look into creating an online chess game application soon!
  - Pmop 7y ago
    Hey, yo! I was thinking doing the same. I was thinking in something with link sharing i.e. you create a game session and then get a link you can share with the second player and spectators.
tdons 7y ago
Cool, thanks for sharing. I'll check it out once github is back up :-)
onefuncman 7y ago
Good job, you crashed GitHub.
dabei 7y ago
Nice, great to see more open source efforts on Chess. GitHub is down and I can’t quite tell what is the need you are trying to address with this library.
- jaeheonshim 7y ago
  GitHub is down at the worst possible moment for me... Hopefully they'll fix it up soon
durbat 7y ago
You need to switch your data representation to 0x88 [1] or bitbords [2] to get anything performant. You won't get anywhere with a class hierarchy [1] https://www.chessprogramming.org/0x88 https://www.chessprogramming.org/0x88 [2] https://www.chessprogramming.org/Bitboards https://www.chessprogramming.org/Bitboards
- saagarjha 7y ago
  Perhaps they don’t need anything performant? You don’t need a bitboard for everything. (They’re also not always performant.)
- voz_ 7y ago
  If the API is well written, this is an implementation detail.
  - durbat 7y ago
    Well, it depends on the project goals. For a GUI app I can agree but good luck writing a chess engine where data representation is hidden behind an abstract interface.
    - blackflame7000 7y ago
      Abstract as in using bit-boards or proper abstraction as in giving a clean interface to interact with a model and let the implementation worry about itself?
- thom 7y ago
  If someone just wants a library to power a chess UI this isn't really necessary. Either way I'd suggest the author finish off the current implementation until they can get perft and other automated tests up and running first. That said, chess programming is a _wonderful_ education in Computer Science, and you'll be following in the footsteps of so many great figures in the industry. Understanding bitboards and how to work with them can take you all the way from the bit-twiddling chapters of The Art of Computer Programming, right up to recent advances in CPU architecture and instruction sets. Learning how search works will teach you both very low techniques and high level heuristics in performance optimisation. And of course you can go all all the way up to recent advances in evaluation from deep learning.
nurettin 7y ago
As someone who has implemented online multiplayer tbs games before, this is exactly the kind of thing you would use at the backend. However, you also need the same code running on the frontend in order to do validations before sending moves to the backend. That optimization helps distribute some server load and gets you immediate feedback. In Java's case, I'd use some java to js or java to kotlin to js transpilation.
- Pmop 7y ago
  Is performing chess validations that heavy, if you're serving ~10,000 games? (just asking for a friend)
  - nurettin 7y ago
    To do all validations and move suggesions on the server side causes data traffic for no reason. Not just cpu time. It is senseless.
    - nurettin 7y ago
      As a clarification, of course you will validate all moves on the server side and make sure client side state is consistent, but what I meant by validation is when you have to give every feedback from the server back to the client you will quickly find yourself in a ddos situation with so many players online.
koff3 7y ago
There is also http://www.chesspresso.org/ http://www.chesspresso.org/ which worked great for PGN and FEN processing.
- WoodenChair 7y ago
  Official author GitHub repository: https://github.com/BernhardSeybold/Chesspresso https://github.com/BernhardSeybold/Chesspresso Has had some very minor fixes since the last source forge version.
johnathana 7y ago
You can check also my lib magnus4j for some ideas: https://github.com/johnathana/magnus4j https://github.com/johnathana/magnus4j
pgt 7y ago
When I was 17, I built a Java Chess AI for a school project called Chessmate. The AI couldn't castle or en passant, but it won a regional prize that got lost in the mail. 10 Years later, the code (which I had put on GitHub) made its way into a Minecraft mod called MineChess: http://petrustheron.com/posts/chessmate.html http://petrustheron.com/posts/chessmate.html Source code: https://github.com/theronic/chessmate https://github.com/theronic/chessmate
lspears 7y ago
I loved building my chess library and would encourage other developers to try it. It is large and complex enough to test your abilities. Building it in a idiomatic, testable, and performant way really encourages software engineering skills instead of just coding. I felt like I didn’t really write solid go code until I finished my chess library. https://github.com/notnil/chess https://github.com/notnil/chess
aaron_seattle 7y ago
Hats off to you for tackling such a hard problem. Coding chess is a beast. I cut you this one issue, https://github.com/jaeheonshim/ChessBoard/issues/1 https://github.com/jaeheonshim/ChessBoard/issues/1 I think your castling logic is incomplete? Worth a double check.
mk_chan 7y ago
The first thing you'd want to implement is perft: https://www.chessprogramming.org/Perft_Results https://www.chessprogramming.org/Perft_Results It actually doubles as a performance test(like it's name) and a debugging tool to verify that you can generate moves correctly by comparing your numbers vs the positions given on the website and a few large suites. I'd encourage you to get involved with the passionate community at talkchess: http://talkchess.com/forum3/index.php http://talkchess.com/forum3/index.php And join a small group on IRC at Freenode ##chessprogramming where we discuss chess AIs, libraries and often other games like Ataxx and Go. I myself am an author of a chess library: https://github.com/Mk-Chan/libchess https://github.com/Mk-Chan/libchess ! Great to see development for Java as well
skocznymroczny 7y ago
Interesting. What is the reason for starting a new project in Java if much better alternatives such as Rust or Kotlin exist?
jordiburgos 7y ago
Could be nice to see the board.toString() with a Unicode representation of the board. Edit: the comment text does not allow Unicode characters.

62 points by jaeheonshim 7y ago

suyash 7y ago

Awesome, I would encourage turn this into a actual chess game using JavaFX.

jaeheonshim 7y ago
That's a great idea, I'm going to look into creating an online chess game application soon!
- Pmop 7y ago
  Hey, yo! I was thinking doing the same. I was thinking in something with link sharing i.e. you create a game session and then get a link you can share with the second player and spectators.

tdons 7y ago

Cool, thanks for sharing. I'll check it out once github is back up :-)

onefuncman 7y ago

Good job, you crashed GitHub.

dabei 7y ago

Nice, great to see more open source efforts on Chess. GitHub is down and I can’t quite tell what is the need you are trying to address with this library.

jaeheonshim 7y ago
GitHub is down at the worst possible moment for me... Hopefully they'll fix it up soon

durbat 7y ago

You need to switch your data representation to 0x88 [1] or bitbords [2] to get anything performant. You won't get anywhere with a class hierarchy [1] https://www.chessprogramming.org/0x88 https://www.chessprogramming.org/0x88 [2] https://www.chessprogramming.org/Bitboards https://www.chessprogramming.org/Bitboards

saagarjha 7y ago
Perhaps they don’t need anything performant? You don’t need a bitboard for everything. (They’re also not always performant.)
voz_ 7y ago
If the API is well written, this is an implementation detail.
- durbat 7y ago
  Well, it depends on the project goals. For a GUI app I can agree but good luck writing a chess engine where data representation is hidden behind an abstract interface.
  - blackflame7000 7y ago
    Abstract as in using bit-boards or proper abstraction as in giving a clean interface to interact with a model and let the implementation worry about itself?
thom 7y ago
If someone just wants a library to power a chess UI this isn't really necessary. Either way I'd suggest the author finish off the current implementation until they can get perft and other automated tests up and running first. That said, chess programming is a _wonderful_ education in Computer Science, and you'll be following in the footsteps of so many great figures in the industry. Understanding bitboards and how to work with them can take you all the way from the bit-twiddling chapters of The Art of Computer Programming, right up to recent advances in CPU architecture and instruction sets. Learning how search works will teach you both very low techniques and high level heuristics in performance optimisation. And of course you can go all all the way up to recent advances in evaluation from deep learning.

nurettin 7y ago

As someone who has implemented online multiplayer tbs games before, this is exactly the kind of thing you would use at the backend. However, you also need the same code running on the frontend in order to do validations before sending moves to the backend. That optimization helps distribute some server load and gets you immediate feedback. In Java's case, I'd use some java to js or java to kotlin to js transpilation.

Pmop 7y ago
Is performing chess validations that heavy, if you're serving ~10,000 games? (just asking for a friend)
- nurettin 7y ago
  To do all validations and move suggesions on the server side causes data traffic for no reason. Not just cpu time. It is senseless.
  - nurettin 7y ago
    As a clarification, of course you will validate all moves on the server side and make sure client side state is consistent, but what I meant by validation is when you have to give every feedback from the server back to the client you will quickly find yourself in a ddos situation with so many players online.

koff3 7y ago

There is also http://www.chesspresso.org/ http://www.chesspresso.org/ which worked great for PGN and FEN processing.

WoodenChair 7y ago
Official author GitHub repository: https://github.com/BernhardSeybold/Chesspresso https://github.com/BernhardSeybold/Chesspresso Has had some very minor fixes since the last source forge version.

johnathana 7y ago

You can check also my lib magnus4j for some ideas: https://github.com/johnathana/magnus4j https://github.com/johnathana/magnus4j

pgt 7y ago

When I was 17, I built a Java Chess AI for a school project called Chessmate. The AI couldn't castle or en passant, but it won a regional prize that got lost in the mail. 10 Years later, the code (which I had put on GitHub) made its way into a Minecraft mod called MineChess: http://petrustheron.com/posts/chessmate.html http://petrustheron.com/posts/chessmate.html Source code: https://github.com/theronic/chessmate https://github.com/theronic/chessmate

lspears 7y ago

I loved building my chess library and would encourage other developers to try it. It is large and complex enough to test your abilities. Building it in a idiomatic, testable, and performant way really encourages software engineering skills instead of just coding. I felt like I didn’t really write solid go code until I finished my chess library. https://github.com/notnil/chess https://github.com/notnil/chess

aaron_seattle 7y ago

Hats off to you for tackling such a hard problem. Coding chess is a beast. I cut you this one issue, https://github.com/jaeheonshim/ChessBoard/issues/1 https://github.com/jaeheonshim/ChessBoard/issues/1 I think your castling logic is incomplete? Worth a double check.

mk_chan 7y ago

The first thing you'd want to implement is perft: https://www.chessprogramming.org/Perft_Results https://www.chessprogramming.org/Perft_Results It actually doubles as a performance test(like it's name) and a debugging tool to verify that you can generate moves correctly by comparing your numbers vs the positions given on the website and a few large suites. I'd encourage you to get involved with the passionate community at talkchess: http://talkchess.com/forum3/index.php http://talkchess.com/forum3/index.php And join a small group on IRC at Freenode ##chessprogramming where we discuss chess AIs, libraries and often other games like Ataxx and Go. I myself am an author of a chess library: https://github.com/Mk-Chan/libchess https://github.com/Mk-Chan/libchess ! Great to see development for Java as well

skocznymroczny 7y ago

Interesting. What is the reason for starting a new project in Java if much better alternatives such as Rust or Kotlin exist?

jordiburgos 7y ago

Could be nice to see the board.toString() with a Unicode representation of the board. Edit: the comment text does not allow Unicode characters.