♟️ Chess Game - C++ & SDL

🔧 Technology Stack

Compilation:

• C++20
• CMake
• Make

Framework & Libraries:

• SDL2
• SDL2_image
• SDL2_mixer
• SDL2_ttf
• nlohmann_json

---

💻 Build & Run Instructions

🖥️ Windows

cmake -B build
cd build
cmake --build .
.\Debug\ChessGame.exe

🍎 MacOS / Linux

cmake -B build
cd build
make
./ChessGame

---

📦 JSON Structure

The JSON file contains a single key:

• "pieces": An array of exactly 32 elements representing every piece in the game.

---

🔍 Pieces Array Details

Each position in the "pieces" array corresponds to a specific chess piece following this exact order:

Index Range	Description	Example Piece Types
0 – 7	Black major pieces	Rook, Knight, Bishop, Queen, King, Bishop, Knight, Rook
8 – 15	Black pawns	Pawn x8
16 – 23	White pawns	Pawn x8
24 – 31	White major pieces	Rook, Knight, Bishop, Queen, King, Bishop, Knight, Rook

🔗 Important Notes:

• The value at each index represents the position on the board (from 0 to 63) where the corresponding piece is located.
• If a piece has been captured, its corresponding entry will be null.

---

🗺️ Board Index Mapping

The chessboard is flattened into a 1D array (0–63) ordered left-to-right and top-to-bottom:

Loading a play from JSON:

1. File path: assets/json/board_pieces.json
2. It only contains a key called "pieces" which is an array.
3. Pieces array: contains 32 positions. Each position refers to a piece from the game, starting from top left to bottom right: Rook, Knight, Bishop .... Pawn, Pawn, Pawn ... Pawn, Pawn, Pawn ... Rook, Knight, Bishop
4. Each value in piece's array refers to an index from the Board (one-dimensional array). Those indexes go from 0 to 64 (from top left to bottom right). Each index refers to a col row value. i.e. 1 means (1, 0), 8 means (0, 1), etc.

Some examples:

pieces[0] = 8 -> Means black player Rook is at cell (0,1). pieces[30] = 17 -> Means white player Knight is at cell (1, 2).

---

🚧 Missing Features from Official Chess Rules

These features are not yet implemented in the current version of the game:

• ♟️ Pawn Promotion: Automatically promote a pawn upon reaching the last rank.
• 🤝 Resignation: Allow players to manually resign the game.
• 🏳️ Forfeit (Timeout): Handle player timeouts in time-controlled games.
• ☠️ Dead Position Detection: Detect positions where no checkmate is possible.
• 🔁 Threefold Repetition Rule: Declare a draw when the same position occurs three times.
• ⏱️ Fifty-Move Rule: Declare a draw if no pawn move or capture has occurred in the last fifty moves by each player.

---

✨ Potential Features to be Added

These features are planned or could be considered for future versions:

• ⏳ Time Control: Implement clocks and timers for each player to simulate real tournament conditions.
• 🤝 Draw Offer / Acceptance: Allow players to offer and accept draws during gameplay.