Chess-engine

A fully compliant, playable chess engine written in Lua and rendered with the Love2D game framework forked from https://github.com/Azzla/chess-engine. Features a multi-threaded AI opponent with alpha-beta + quiescence search algorithms.

Completed Goals

• Bug-free legal move generation: Passes all Perfts up to a depth of 5-ply from this testing suite.
• Optimized move generation: Various speed increases have been achieved via table-lookups, init-time move info storage, array indexing over looping, removing table.insert, etc. More optimization is always possible but its good enough for the time being.
• Playable AI opponent: Opponent can find good moves in most positions and generally avoids bad moves. I've noticed a bug where the search thread hangs and it never returns the best move, but it seems to occur rarely.

I'm not the original developer, I forked the project and did a few small tweaks like zoom out the screen and tweaking the screen resolution to make it fit on mobiles.

I may add some more mobile features in the future.

This is my second chess project forked, the other one can be found here: https://openrepos.net/content/glitchapp/love-chessboard

Difference between the two chess games:

Chess-engine:

- Features A.I. oponent (you can only play against cpu)

- Clock

- Smooth animations

love-chessboard:

- No A.I. opponent (you can only play against another human player)

- 4 sets available: "fritz", "sharm", "smirf" and "warlord"

- Portrait and landscape mode

Choose whatever chess you prefer and enjoy!

v0.2 adds:

- New set of pieces: "sharm"

- Normal maps and global illumination

This new version pushes the gpu and may not perform well on old devices, if you experience bad performance please use v0.1

v0.3 adds: Deprecated lua functions updated with their newer counterparts. 

This build works on sailfish os 5.0 (tampella). It problably won't work on older sailfish versions: some of the new lua functions do not work on older lua, if the game crashes on older sailfish please use version 0.2 instead.

v0.4 adds: Landscape mode. Game can now be played in both portrait and landscape mode.

v0.4.2 update: Fixed issues with the pull menu.

v0.5: The rendering pipeline has been upgraded to 3D. The game now renders almost entirely in 3D — only the pieces remain as 2D sprites, but they are positioned within the 3D space.

If you connect a keyboard, you can adjust the camera angle using the arrow keys.

v0.6 adds:

• Improved visual feedback when moving pieces: Board squares now highlight when you pick up and drag a piece, making it easier to visualize possible movements.
• Background music: You can now play music in the background.
  • Press M to toggle music on/off
  • Press N to play a new random track

Chess Engine 0.7 – What’s New:

• Full board rotation support and landscape mode compatibility.
• High-quality textures for the board for a more realistic look.
• New 3D pre-rendered piece models with improved detail.
• Enhanced lighting and reflections.

v0.8 adds:

- Prerendered pieces in different angles

- Camera can now be moved with two fingers (press and drag to move the camera)

v0.9 Update Highlights

• Pull Menu Restored: Swipe down to restart the game or access options.
• New Options:
  • AI Plays Black – Turn off to play against another human.
  • Allow Undo – Work in progress (not functional yet).
  • Auto-Queen Promotions – Pawns auto-promote to queens.
  • Reflections – Previously applied only to the board; now pieces also reflect on the board! Disable if your device struggles with framerate.

v1.0 introduces:

• A new optimized lighting system that improves the visual illumination of chess pieces while maintaining high performance.

v1.2 adds:

• Two new options in the Options menu: Illumination and Background.
• Free camera movement (keyboard only; use WASD to move – touch controls are not supported).

Tip: Among all graphics options, Global Illumination is the most performance-intensive. If you need better performance, this is the first option to turn off.

v1.3 adds: new options and three playable old builds of the game:

• v0.1 – Closest to the original developer’s vision, using the original 2D assets.
• v0.2 – Still 2D, but with updated assets for a refreshed look.
• v0.6 – First 3D version of the game, highly performant thanks to minimal visual effects.

Note: Loading these old versions is not fully beta-tested. Some features may be missing or unstable—for example, they do not include the pull menu, and attempting to use it may cause a crash.

Version 1.4 introduces ChatHUD and NoobHub.

Players familiar with my other games that include ChatHUD and NoobHub will already know what these tools are. For those who are new to them, they are too complex to fully explain in a short release note. Please refer to the project repository for detailed information about what they are, how to use them, and how to set them up.

In short, ChatHUD and NoobHub provide a chat and multiplayer client/server system that allows you to:

• Chat with other players
• Use natural-language commands (for example, toggling options simply by typing what you want)
• Talk to, ask questions to, and even play with AI models

As impressive as that may sound, the internal game algorithms may still play better than some AI models!

For this game, ChatHUD also introduces a special feature: chess move parsing. In practice, this means you can use NoobHub to play chess with other players over the network.

Important: These new features are highly experimental and currently in beta. There is no guarantee that they will work correctly. They are primarily intended for beta testers, contributors, and developers.

If you are not part of those groups, you are still welcome to try them—as long as you are tolerant of bugs or incomplete behavior. Otherwise, you can safely ignore these features, as they do not affect the rest of the game's functionality.

Enjoy!

Version 1.5 adds: The 3 sets of piece assets can now be toggled even during gameplay with keyboard (keys 1 to 3) and the pull menu (select "Toggle piece set")

Version 1.6 introduces subtle UI improvements that make it easier to see which pieces you are hovering over or dragging, as well as their target squares, using animated selection assets and enhanced highlighting.

Note I removed versions 1.1 till 1.5 because there's nothing relevant difference between them and they use too much space due to the music.