Minecraft Alpha-v1.2.6

This is based off of real Minecraft Alpha v1.2.6, the decompiled source code has been ported to TeaVM with as minimal changes as possible. Worlds and settings are saved to your browsers local storage using IndexedDB, worlds are compressed using jzlib's GZIP, existing uncompressed worlds will be loaded uncompressed and be compressed when the game writes to the file.

Play the official release (No download required)

Download offline HTML file

Making a client

Gradle

After modifying files in src/main/java you can compile your changes to the javascript client by running gradlew generatejavascript, for linux run ./gradlew generatejavascript. This will then transpile the Java code into javascript files in web/js/.

Textures

The textures are compiled into resources.mc using Laxdude's EPK Compiler. The resources are located in resources/, after modifying the resources you can compile them using CompileEPK, and for Linux use ./CompileEPK.sh.

Offline Download

As of right now there is no system to compile an offline download, so you will have to manually copy and paste the javascript from web/js/app.js into the HTML file, for the resources.mc just encode the file using Base64 and paste it into the assets div.

Muliplayer

Multiplayer has been removed because I am too lazy to rewrite it, unless you're planning on porting it yourself, do NOT ask for multiplayer, it will NOT be added anytime soon!

If you do want to try to port it then I would recommend using a diff of Alpha v1.2.6 and this project to port the original code back over, all packet classes and networking code has been completely removed.

Texture Packs

This is pretty much self explanitory, just make sure the textures have the same structure as in resources/, and then add it to a ZIP file, if a texture pack does not work then most likely it is not for this version of Minecraft. You're probably gonna have to make your own texture pack, texture packs for Alpha are very rare these days.

How to decompile older Minecraft versions

To decompile older Minecraft versions you can use RetroMCP!

RetroMCP is a rewrite of MCP that adds support for many different older versions of Minecraft that were never supported by MCP. To get started head over to the RetroMCP GitHub and download the latest release. Make sure you have Java 8 (or higher) installed in order to run and decompile Minecraft versions.

Code used within this project

• Modified version of Lax1dude's OpenGL Emulator from 0.30-WebGL
• Decompiled Minecraft Alpha v1.2.6 source code