chess

Chess game with local, engine and remote options for C++ course

If you don't want to build from source, there are compiled executables available on the release page.

Windows build instructions:

Load the CMake project (your IDE probably has an option for this). Build the project. If you are working in the command line, follow the steps below, where you replace 'cmake' and 'make' with the corresponding executables (or run them as commands if their executables are included in your system path).

Linux build instructions:

To build from source, run the following commands from the chess directory:

• cmake .
• make

The executable should now be in the chess directory. If any of the above steps fail due to Qt not being found, specify the correct CMAKE_PREFIX_PATH in CMakeLists.txt (where it says "C:/Qt/5.15.2/msvc2019" now).

Chess engine:

For the chess engine to work, a stockfish executable must be in your path variable. You can test this by opening a command prompt and typing stockfish. You can get Stockfish here. This program is tested to work with Stockfish 13. Stockfish is ditributed under the GNU General Public License v3.0.

The program consists of a basic chess game, only mouse clicks are supported to interact with the program. On the right side of the screen next to the board is a live report of the moves played in reversible algebraic notation. You can play against a human opponent using the same computer or play against stockfish on 3 different levels. The plan was to be able to play against another player over the internet, but unfortunately this doesn't seem to work (yet). The program relies on Qt and will not work without it. On Windows, all necessary files should be included in the installer. On Linux, there are some commands below that might help if Qt is missing on your machine. Since Qt is used, I assume that the license that allows me to do that applies to this program as well (I think this is GNU GPL as well).

This program has a few custom exit codes (passed on through signals and slots by Qt until the main application is reached and the program exits):

• 80: an empty field somehow managed to get moves from the move calculator, since this is impossible, the game doesn't know how to continue and exits to prevent further unexpected behaviour
• 81: while trying to find one of the kings, the program struck out, so one of them is missing, which is impossible; here too an exit is triggered to prevent further unexpected behaviour
• 82: a parameter that should be white or black, is empty, which is undefined behaviour, so any further unpredictable action is avoided by exiting
• 83: a parameter that should distinguish between client and server mode is empty, since the program needs this information to continue, it just breaks off here
• 84: while trying to start up stockfish as a command line process, an error occurred, since this is probably due to stockfish being absent, the program does not retry but exits instead
• 85: stockfish normally gets 30 seconds to respond after each command and didn't respond in time here
• 86: the separator between the origin and the destination field in the history table is missing for one or more moves
• 87: the stockfish engine was ordered to play a move after the game has finished, it is not supposed to be

These situations are all impossible to reach as far as I know (except for 84 and maybe 85 with stockfish), but who knows where I might have made a mistake. If any of the above situations occur, the program will exit. Please do let me know if this happens (by submitting an issue on the Github repo). Keep in mind that problems with stockfish are especially hard to fix, since the stockfish output is not reproducible.

Some commands that may help if the program doesn't immediately start on linux:

• apt install qt5-default
• apt install libxcb-xinerama0
• export QT_QPA_PLATFORM=wayland, where you can replace wayland with whatever you want to use (I think default is xcb, which is what the previous command installs)