Custom Python Chess Engine

Welcome to the Custom Python Chess Engine! This project is a fully functional chess application developed in Python. It features a complete set of chess rules, a graphical user interface (GUI) built with Pygame, and an integrated AI opponent that uses advanced search algorithms to play against you.

Features

Core Mechanics & Rules

• Complete Move Generation: Supports all standard piece movements.
• Advanced Rules: Fully implements Castling, En Passant, and automatic Pawn Promotion.
• Game States: Accurate detection of Checks, Checkmates, and Stalemates.
• Move Log: A dedicated panel that records and displays the move history using standard algebraic chess notation.

Graphical User Interface (GUI)

• Pygame-based UI: Clean, responsive, and interactive 2D chessboard.
• Square Highlighting: Highlights the currently selected piece and shows all its valid destination squares to assist the player.
• Smooth Animations: Pieces glide smoothly across the board when a move is executed.
• Keyboard Controls:
  • Press z to undo the last move.
  • Press r to reset the board and start a new game.

Artificial Intelligence (AI)

• NegaMax with Alpha-Beta Pruning: The engine uses an optimized NegaMax search algorithm coupled with Alpha-Beta pruning to evaluate positions efficiently and choose the best moves.
• Multiprocessing: The AI calculates its moves on a separate background process. This ensures the GUI remains completely responsive while the AI is "thinking," allowing you to interact with the board or undo moves seamlessly.

Project Structure

• ChessMain.py: The entry point of the application. Handles the Pygame GUI, user inputs, and multiprocessing for the AI.
• ChessEngine.py: The core backend. Manages the game state, validates moves, and enforces chess rules.
• smartmovefinder.py: The AI module. Contains the scoring functions and NegaMax alpha-beta search algorithms.

How It Works

1. Game State Management: The board is represented as a 2D list. ChessEngine.py evaluates the board state to generate valid moves based on whose turn it is, considering checks and pins.
2. Move Processing: When a player clicks to move a piece, the move is validated against the generated list. If valid, the move is applied, and turn control switches.
3. AI Integration: When it's the AI's turn, ChessMain.py spawns a background process that calls smartmovefinder.py. The AI evaluates future possible board states up to a certain depth (default is depth 4), scoring them based on material advantages. The best found move is then passed back to the main thread via a queue and executed on the board.

How to Run the Project

Prerequisites

• Python 3.x: Make sure you have Python installed on your system.
• Pygame: This project requires the Pygame library for rendering the UI.

Installation & Execution

1. Clone the repository or download the project files.
2. Open your terminal or command prompt.
3. Install Pygame (if you haven't already):

   pip install pygame

4. Run the main application file:

   python project_files/ChessMain.py

Enjoy playing against the engine or studying the move generations!