Chessy ♟️

A CLI-based chess game engine and interface written in C++. This project provides a complete chess-playing experience in the terminal, featuring full move validation, game state detection, and the ability to save and load positions using FEN strings.

Key Features

• Full Chess Logic: All standard moves are implemented, including pawn promotion, en passant, and castling.
• Interactive Terminal Interface: Play a full game from start to finish using the form Square to Square form (e.g., e2, e4) which I think is much easier for chess beginners to understand than the standard algebraic notation -Just the distination as input-
• Save & Load Games: Games can be saved at any point and loaded later to resume play.
• FEN Support: Start a game from any board position by providing a valid Forsyth-Edwards Notation (FEN) string.

Engine & Rule Validation

• Legal Move Generation: The engine accurately calculates all possible legal moves for any given piece, respecting pins and other complex board states.
• Game State Detection: The game automatically detects and announces key states:
  • Check & Checkmate
  • Stalemate
  • Draw by Insufficient Material
  • Draw by Threefold Repetition (Using Zobrist Hashing)
  • Draw by the 50/75-move rule

Getting Started

Follow these instructions to compile and run the project on your local machine.

Prerequisites

You will need a C++ compiler that supports C++17 or newer. The most common compiler is g++, which is part of the GCC toolchain.

Building from Source

Clone the repository:

git clone https://github.com/ysfw/Chessy.git

Compile the source code:
Use the following command to compile all necessary files into a single executable named chessy:

make

Note: A Makefile is provided to simplify the build process. It automatically compiles all .cpp files in the main directory and the pieces folder.

Windows UTF-8 Note

On Windows, you may need to set the console to UTF-8 to properly display Unicode characters (The chess pieces).
Run this command before executing the program:

chcp 65001

Run the game:

./chessy

How to Play

After launching the executable, you will be greeted with the main menu.

Main Menu

--- Chessy ---
1. New Game
2. Load from FEN
3. Load Saved Game
4. Exit
Choose an option:

• New Game: Starts a standard game of chess from the initial board setup.
• Load from FEN: Prompts you to enter a FEN string to set up a custom board position.
• Load Saved Game: Lists previously saved games and allows you to resume one.

Gameplay

• Selecting a Piece: To make a move, first enter the coordinate of the piece you want to move (e.g., e2).
• Viewing Moves: The game will display all legal moves for the selected piece. Capturable pieces are highlighted in red.
• Making a Move: Enter the coordinate of the destination square (e.g., e4).
• Changing Selection: If you want to select a different piece after viewing moves, simply type back.

Screenshots

• Loading a saved game.

• screenshots of a game in progress, showing the ASCII board and move prompts.