flutter_stockfish_plugin

A Flutter plugin for the Stockfish Chess engine.

The current version is based on Stockfish 16.

Usage

final stockfish = new Stockfish()

// Listen on stdout of Stockfish engine
final stockfishSubscription = stockfish.stdout.listen((line) {
    print("received: $line");
});

// Sending UCI command to get Stockfish ready
stockfish.stdin = 'isready'

stockfish.stdin = 'position startpos moves e2e4' // set up start position
stockfish.stdin = 'go depth 20' // search bestmove with a max septh of 20

// Don't remember to dispose Stockfish when you're done.
// Make shure to dispose Stockfish when closing the app. May use WindowListener.
stockfishSubscription.cancel();
stockfish.dispose();

A complete Example can be found at stockfish_chess_engine.

Web support

Web support is currently experimental and requires manuly adding assets. It uses a version of stockfish compiled with emscripten.

Usage:

• Install emscripten and set the the Environment-Variable EMSDK
• Build the CMakeLists.txt in web/
• Copy the following files to web/stockfish/ in your project:
  • flutter_stockfish_plugin.js
  • flutter_stockfish_plugin.wasm
  • flutter_stockfish_plugin.worker.js
  • js_bindings.js
  • stockfish_data.bin

If a different path should be used: Change the path const's in js_bindungs.js and stockfish_web_bindings.dart

In order to make multithreading available, the site must run in a secure environment. The following headers must be set for this:

• Cross-Origin-Embedder-Policy: require-corp
• Cross-Origin-Opener-Policy: same-origin

Problems:

• The current version does not include the .js, .wasm and neuralnetwork data as assets. This files will not be bundles automaticly on the web.

Goal of this fork of stockfish_chess_engine

• Avoid limitation. This version does not redirect stdout and stdin of the app for communication with stockfish.
• stdin and stdout were replaced with a fakestream element.
• Stockfish internal logging might not work (could be fixed).

Credits

• Based on and using source code from stockfish_chess_engine
• Using source code from Stockfish.
• Using source code from Flutter Stockfish.

Directory src/Stockfish contains the latest current release. The code is modified to use a different communication interface. The original license for Stockfish can be found in their GitHub repository.

Directory web/ may contains code compiled from emscripten. Emscripten is licensed among others under the MIT License. License Page