OpenRCT2mini

A fork of OpenRCT2 v0.5.0 (e65fb01 on develop) targeting low-spec ARM handhelds, for now only the Miyoo Mini and Miyoo Mini Plus running OnionUI. The overall goal is to fit a OpenRCT2's vanilla-compatible feature set (with some raised limits and non-memory intensive features) onto 128-256 MB devices running ancient toolchains.

This is a hard fork. The game has been aggressively trimmed and backported to older dependencies. We may try to sync to a newer version in the future, but the core game is feature complete at v0.5.0, so eh.

Status

OpenRCT2mini is currently playable. We match upstream v0.5.0 minus things that don't make sense on a handheld: multiplayer, plugins/scripting, OpenGL, FLAC, Discord-RPC, Japanese/Chinese/Arabic language options (IPC eats too much memory) are all in the bin.

Installing on the device

OpenRCT2mini ships as an OnionUI port. It appears in your Game Library under the Simulation category.

It does not contain RCT2 game data.

1. Download the latest release.
2. Extract the .7z to the root of your Miyoo Mini's SD card.
3. Copy your legitimately-owned RollerCoaster Tycoon 2 install to /SDCARD/Roms/PORTS/Games/OpenRCT2mini/rct2/. The folder must contain the original Data/ and ObjData/ directories with g1.dat, css1.dat, etc.
4. From the OnionUI Game Switcher, run Refresh roms. "OpenRCT2mini" appears in the Simulation category in your Game Library.

Optionally, RCT1 can be placed at /SDCARD/Roms/PORTS/Games/OpenRCT2mini/rct1/ to enable RCT1 scenarios.

Controls

  D-pad        Move cursor (accelerates after 300 ms hold)
  A            Left click
  B            Right click
  X            Shade window (hold to shade/unshade all windows)
  Y            Rotate construction object clockwise
  L1           Shift modifier (raise placement Z, vertical-stack scenery, etc.)
  R1           Hold for fast cursor (~2.5x speed); also acts as gamepad modifier button
  L2           Rotate view counter-clockwise
  R2           Rotate view clockwise
  L1 + R1      Ctrl modifier (sample-and-lock placement Z onto a clicked element)
  R1 + L2      Zoom out
  R1 + R2      Zoom in
  R1 + X       Close window
  R1 + Y       Rotate construction object counter-clockwise
  Start        Confirm / open in-game menu
  Select       Cancel / back

On-screen keyboard

  D-pad        Move selection between keys
  A            Insert highlighted character
  B            Backspace
  X            Insert space (full layout) / Toggle sign on `-` (numpad)
  Y            Toggle Caps Lock
  L1           Move text cursor left
  R1           Move text cursor right
  L2           (Console only) Scroll output up by one page
  R2           (Console only) Scroll output down by one page
  Start        Commit and close (submits one line if used in console)
  Select       Cancel and close (exits the console if used there)

Building

The cross-build runs entirely inside Docker; no host installation of the toolchain or its dependencies is required other than Docker itself.

./Packaging/miyoo_mini/build.sh

That script will:

1. Build the openrctmini-toolchain Docker image (first run only, ~10 min). The image derives from ghcr.io/onionui/miyoomini-toolchain and adds pkg-config plus the libraries OpenRCT2 needs that the upstream image doesn't ship (libzstd, libogg, libvorbis, libzip, nlohmann-json, the patched XK9274/sdl2_miyoo SDL2). Subsequent runs reuse the image.
2. Run cmake + make inside the image, producing build-arm/openrct2.
3. Smoke-test the binary under qemu-arm-static to catch any GLIBC / loader issues before SD-swapping.
4. Run package.sh to produce a release archive at dist/OpenRCT2mini-<version>-<git-short>.7z (Onion port-collection format — extract at SD-card root).

A native host build for development iteration is also supported via the project's standard CMake build (the upstream OpenRCT2 path); see Packaging/miyoo_mini/build.sh for the cross-compile command-line flags that should be mirrored on host for an apples-to-apples comparison. I've only tested this on Linux.

Scope of the fork and what this project does NOT do

• We don't contribute fixes back to OpenRCT2 upstream. Most of the changes are device-specific and would not improve upstream OpenRCT2 on desktop platforms.
• We aren't matching OpenRCT2's release cadence. The fork is pinned to upstream commit e65fb01. Future upstream changes will be considered case by case if they're worth merging.
• We aren't bundling or distributing Chris Sawyer's RollerCoaster Tycoon 1 / 2 game data. Those files belong to Atari / Infogrames and the user. It's on Steam and GOG, go buy it!

Licensing

OpenRCT2mini inherits OpenRCT2's GNU GPL v3 license (licence.txt). All OpenRCT2mini-specific changes: the patches in Packaging/miyoo_mini/, OPENRCT2MINI-tagged source comments, and the build scripts are also GPL-3.0-only.

THIRD_PARTY_NOTICES.md catalogues every third-party component shipped in the binary (vendor SDL2, libzstd, libogg, libvorbis, libzip, nlohmann/json, and the OnionUI toolchain libraries) along with their respective licenses and any patches OpenRCT2mini applies on top.

Where the original OpenRCT2 README went

If you're looking for upstream OpenRCT2's documentation that's at https://github.com/OpenRCT2/OpenRCT2. If your interest is RCT2 on a desktop or mainstream handheld (Steam Deck, etc.) then upstream is what you want.

Generative AI notice

GenAI was used to assist development of this port, caveat emptor.