Arcaea Builder

Build your own Arcaea game client to play self-made or modified official charts!

Features

This project can help you automate the entire workflow for building your own Arcaea game client:

• Unpack original packages automatically (with 7z for iOS and apktool for Android).
• Generate app icons for your choosen image (with puppeteer).
• Patch the game binary automatically.
  • There're some pre-defined offsets (including pack divider) in the example project.
  • You can find more patchable offsets with IDA.
• Manage your packs and songs in a structured manner and build for the server and game client easily.
  • The songs are stored inside the directoryr of its pack.
  • The songs' metadata is stored inside each song's directory.
  • You can modify official songs (see the example) with filters.
  • Supports generate downloadable assets with remote_dl. Previews are made automatically.
• Repack the game packages automatically, with the custom name, version and so on.
  • The build is fully reproducible!

Requirements

• Node.js (v16) and Yarn package manager (v1)
• Chrome browser
• 7z (p7zip-full)
• apktool (v2.5.0)
• jarsigner
• ffmpeg (4.4)

The version above is tested. Other versions may work.

Only tested on Linux. Window and macOS may work.

Usage

Install NPM dependencies with yarn:

yarn

And follow the instructions below.

Project

See the example project.

Filters

You can add filters to a song. Supported filters are:

• cut
  • Params: start, end
  • Cut a song's part from start millseconds to end millseconds. The chart of all difficulties are also cut.
• chartFixSpeed
  • Params: none
  • Remove speed changes from a song's charts. i.e. Set all timing()'s BPM to the song's bpm_base.
• tempoScale
  • Params: factor
  • Speed up or down a song. The chart of all difficulties are also scaled.
  • The factor param is for the tempo. A value < 1 will speed down a song while a value > 1 will speed up a song.
  • Supported factor range is 0.5 - 2.

To apply filters, append a filters key to your song.yaml. For example:

# Cut, then scale tempo to 0.9x
filters:
  - name: cut
    start: 111000
    end: 222000
  - name: tempoScale
    factor: 0.9

Utilities

Extract songinfo

NOTE: You may not need to use this utiltily (especially for official songs). Use from to use an original song in your project.

If your song meta are defined in a songlist file, this utility can help you extract them to each song's directory.

# /path/to/your/songs/songlist must exist
# Extracted song.yaml will be saved in /path/to/your/songs/<songid>
yarn util extract-songinfo /path/to/your/songs

AFF fix

Some self-made charts are broken since some numbers are required to keep two decimal places but they doesn't. The utility can fix the numbers in timing(), arc() and camera() statements.

# Dry run
yarn util aff-fix /path/to/your/project/packs/<packname>/<songname>/*.aff
# Write changes
yarn util aff-fix -w /path/to/your/project/packs/<packname>/<songname>/*.aff

Credits

• ArcaeaModder (Android) for some Android offsets.
• ArcaeaModder (iOS) for some iOS offsets.
• Arcaea-server