Copyright (C) 2013-2015 Phokham Nonava
http://www.fluxchess.com

Pulse Chess is a simple chess engine with didactic intentions in mind. The source code should be easy to read, so that new developers can learn, how to build a chess engine. If you want to roll your own, just fork it and start coding! :)

Pulse Chess is available in Java and C++. Both editions have the same feature set. The Java Edition requires Java 7 for compilation and execution. The C++ Edition is written in C++11. It has been compiled successfully using g++ 4.9.1 and Visual C++ 2013.

Only a couple of basic chess engine features are implemented to keep the source code clean and readable. Below is a list of the major building blocks.

• UCI compatible
  Java Edition: Pulse Chess uses JCPI for implementing the UCI protocol.

• 0x88 board representation
  To keep things simple Pulse Chess uses a 0x88 board representation. In addition piece lists are kept in Bitboards.

• Only material and mobility evaluation
  Currently only material and mobility (to add some variation) are used for calculating the evaluation function. However it should be quite easy to extend it with other evaluation features.

• Using integers for type representation
  Java Edition: Although Java is quite efficient and fast in memory management, it is not fast enough for chess engines. Instead of using objects for important data structures, Pulse Chess uses integers to exploit the Java stack.

• Pseudo-legal move generator
  To keep the source code clean and simple, a pseudo-legal move generator is used. This has the advantage to skip writing a complicated legal move checking method.

• Basic search
  Pulse Chess uses a basic Alpha-beta pruning algorithm with iterative deepening. This allows us to use a very simple time management. In addition there's a basic Quiescent search to improve the game play.

Pulse Chess can hold its own against an average club player. If you want to make it even better, have a look at the following ideas.

• Null Move Pruning
  This will make you faster. A whole lot faster! If done right, it should give you quite a boost.

• Transposition Table
  Although a little bit tricky to get right from the beginning, this technique can make you impressively faster.

• Check Extensions
  This is the one extension I would choose first to implement. If you can control the search explosion, the tactical gain is awesome.

• Passed Pawn
  This will definitely improve your endgame.

• Staged move generation
  Tune your move generation! Don't generate every move upfront. Believe me, you will get a nice speed increase.

Pulse Chess uses Maven for the Java Edition and CMake for the C++ Edition as build systems. To build it from source, use the following steps.

• get it
  git clone https://github.com/fluxroot/pulse.git

• build it
  mvn package

• grab it
  cp target/pulse-<version>.zip <installation directory>

• build it

    mkdir build
    cd build
    cmake -DCMAKE_BUILD_TYPE=Release .. && make && make test && make package
  

  For MSYS environments try specifying the generator:
  cmake -DCMAKE_BUILD_TYPE=Release -G "MSYS Makefiles" .. && make && make test && make package

  For Visual Studio do the following:
  cmake -G "Visual Studio 12 2013" .. && cmake --build . --config Release && ctest && cpack -C Release

• grab it
  cp build/pulse-<version>.zip <installation directory>

The Pulse Chess logo was created by Silvian Sylwyka. Thanks a lot!

Pulse Chess is released under the MIT License.