Tango

Tango is rollback netplay for Mega Man Battle Network.

Supported games

ID	Name	Gameplay support	Save viewer support
MEGAMAN6_FXXBR6E	Mega Man Battle Network 6: Cybeast Falzar (US)	✅ Works great!	🤷 Folder, NaviCust
MEGAMAN6_GXXBR5E	Mega Man Battle Network 6: Cybeast Gregar (US)	✅ Works great!	🤷 Folder, NaviCust
ROCKEXE6_RXXBR6J	Rockman EXE 6: Dennoujuu Falzer (JP)	✅ Works great!	🤷 Folder, NaviCust, Modcards
ROCKEXE6_GXXBR5J	Rockman EXE 6: Dennoujuu Glaga (JP)	✅ Works great!	🤷 Folder, NaviCust, Modcards
MEGAMAN5_TP_BRBE	Mega Man Battle Network 5: Team Protoman (US)	✅ Works great!	🤷 Folder, NaviCust
MEGAMAN5_TC_BRKE	Mega Man Battle Network 5: Team Colonel (US)	✅ Works great!	🤷 Folder, NaviCust
ROCKEXE5_TOBBRBJ	Rockman EXE 5: Team of Blues (JP)	✅ Works great!	🤷 Folder, NaviCust
ROCKEXE5_TOCBRKJ	Rockman EXE 5: Team of Colonel (JP)	✅ Works great!	🤷 Folder, NaviCust
ROCKEXE4.5ROBR4J	Rockman EXE 4.5: Real Operation (JP)	✅ Works great!	🤷 Folder
MEGAMANBN4BMB4BE	Mega Man Battle Network 4: Blue Moon (US)	✅ Works great!	🤷 Folder
MEGAMANBN4RSB4WE	Mega Man Battle Network 4: Red Sun (US)	✅ Works great!	🤷 Folder
ROCK_EXE4_BMB4BJ	Rockman EXE 4: Tournament Blue Moon (Rev 0 only) (JP)	✅ Works great!	🤷 Folder
ROCK_EXE4_RSB4WJ	Rockman EXE 4: Tournament Red Sun (Rev 0 and 1) (JP)	✅ Works great!	🤷 Folder
MEGA_EXE3_BLA3XE	Megaman Battle Network 3: Blue (US)	✅ Works great!	❌ None
MEGA_EXE3_WHA6BE	Megaman Battle Network 3: White (US)	✅ Works great!	❌ None
ROCK_EXE3_BKA3XJ	Battle Network Rockman EXE 3: Black (Rev 1 only) (JP)	✅ Works great!	❌ None
ROCKMAN_EXE3A6BJ	Battle Network Rockman EXE 3 (Rev 1 only) (JP)	✅ Works great!	❌ None
MEGAMAN_EXE2AE2E	Megaman Battle Network 2 (US)	🤷 Works, with minor issues	❌ None
ROCKMAN_EXE2AE2J	Battle Network Rockman EXE 2 (Rev 1 only) (JP)	🤷 Works, with minor issues	❌ None
MEGAMAN_BN@@AREE	Megaman Battle Network (US)	🤷 Works, with minor issues	❌ None
ROCKMAN_EXE@AREJ	Battle Network Rockman EXE (JP)	🤷 Works, with minor issues	❌ None

Design

Tango is composed of two parts: the launcher and the core. The launcher performs high-level control operations, such as starting matches and configuration, while the core performs emulation and netplay. There are additional supplementary tools (replayview, replaydump, keymaptool) that the launcher may also use for certain specialized operations.

The core and launcher send IPC requests to each other over stdout/stdin pipes.

Building

Core

The core is written in Rust. Despite being for Windows, you must have a POSIX-y MinGW environment set up. The following instructions are for Ubuntu.

1. Install Rust.

   curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh

2. Install the Rust target and toolchain for x86_64-pc-windows-gnu.

   rustup target add x86_64-pc-windows-gnu
   rustup toolchain install stable-x86_64-pc-windows-gnu

3. Install mingw-w64.

   sudo apt-get install -y mingw-w64

4. Dowload the DLLs for SDL2.

   pushd core &&
   ./get-windows-sdl.sh &&
   popd

5. Ensure mingw-w64 is using the POSIX threading model.

   sudo update-alternatives --install /usr/bin/x86_64-w64-mingw32-gcc x86_64-w64-mingw32-gcc /usr/bin/x86_64-w64-mingw32-gcc-win32 60 &&
   sudo update-alternatives --install /usr/bin/x86_64-w64-mingw32-gcc x86_64-w64-mingw32-gcc /usr/bin/x86_64-w64-mingw32-gcc-posix 90 &&
   sudo update-alternatives --config x86_64-w64-mingw32-gcc &&
   sudo update-alternatives --install /usr/bin/x86_64-w64-mingw32-g++ x86_64-w64-mingw32-g++ /usr/bin/x86_64-w64-mingw32-g++-win32 60 &&
   sudo update-alternatives --install /usr/bin/x86_64-w64-mingw32-g++ x86_64-w64-mingw32-g++ /usr/bin/x86_64-w64-mingw32-g++-posix 90 &&
   sudo update-alternatives --config x86_64-w64-mingw32-g++

6. Build the core.

   cd core &&
   cargo build --target x86_64-pc-windows-gnu

Launcher

The launcher is written in Node + Electron.

1. Run npm install to get all Node dependencies.

   cd launcher &&
   npm install

2. Make a dev-bin directory in launcher and copy the core files into it. Note you will need to do this on every rebuild.

   mkdir launcher/dev-bin &&
   cp /usr/x86_64-w64-mingw32/lib/libwinpthread-1.dll \
       /usr/lib/gcc/x86_64-w64-mingw32/9.3-posix/*.dll \
       core/target/x86_64-pc-windows-gnu/release/tango-core.exe \
       core/target/x86_64-pc-windows-gnu/release/replayview.exe \
       core/target/x86_64-pc-windows-gnu/release/replaydump.exe \
       core/target/x86_64-pc-windows-gnu/release/keymaptool.exe \
       launcher/dev-bin

3. In the launcher directory, you can use the following commands:

   npm run start  # start webpack (keep this running in the background)
   npm run start:main  # start electron (run this in a new terminal)

Server

Signaling

The signaling server is the remote HTTP server-based component that Tango connects to. It doesn't actually do very much, so you can run it on absolutely piddly hardware. All it does is provide signaling by sending WebRTC SDPs around.

If you already have Rust installed, you can build it like so:

1. Enter the core directory and build it.

   cd core &&
   cargo build --release --bin tango-signaling-server

That should be it! The server should be available in the usual Rust output directory.

ICE configuration

An ICE configuration server is not provided. You must write your own. Note that by default Tango will use Google's public STUN servers, but will not use any TURN servers.

If you want to guarantee connections across even funny NATed connections, you will need to use an ICE configuration server. This can be configured in Tango under Settings > Advanced > ICE configuration endpoint.

The ICE configuration server must:

• Run over HTTP or HTTPS.
• Accept, via POST, GetRequest and return GetResponse as defined in core/tango-protos/src/protos/iceconfig.proto. Note that these must be in serialized Protobuf format.

Automatic Updates

Whenever a new version of Tango is released, Tango will download the update for you automatically. When you see a purple dot on the Settings cog in Tango, the update is currently being downloaded. When you see a blue dot on the Settings cog, the download is complete, and will be installed once Tango is closed. When you next open Tango, it will be running the up-to-date version.

A note for Linux users:

The .AppImage release for Linux users also fully supports automatic updates! However, due to how the update process works, the original .AppImage you downloaded will be replaced with the latest .AppImage file, effectively renaming it. This renaming will break any scripts, shortcuts, or .desktop entries you may have created against the original filename. However, this can easily be avoided; simply rename your .AppImage to Tango.AppImage - the key is removing the version number. If you do this, you will still receive automatic updates, but the .AppImage won't be renamed after an update, meaning any scripts or shortcuts pointing to Tango will continue working after updates.

Language support

Tango is fully internationalized and supports language switching based on your computer's language settings.

The order of language support is as follows:

• English (en): This is Tango's primary and fallback language. All Tango development is done in English.

• Japanese (ja): This is Tango's secondary but fully supported language. All text in the UI, barring some extremely supplementary text (e.g. the About screen) is expected to be available in Japanese. If new UI text is added, a Japanese translation SHOULD also be provided. Tango releases MUST NOT contain missing Japanese text.

• Simplified Chinese (zh-Hans), Spanish (es): These are Tango's tertiary languages. Support is provided on a best effort basis and translations are provided as available.