# [Rattletrap][]

[![Version badge][]][version]
[![Windows build badge][]][windows build]
[![Build badge][]][build]

Rattletrap parses and generates [Rocket League][] replays.

## Install

Get Rattletrap by downloading and unpacking [the latest release][] for your
platform.

To build Rattletrap from source, install [Stack][]. Then run
`stack --resolver nightly install rattletrap`.

## Replays

Rocket League saves your replays in a folder that depends on your operating system.

- Windows: `%UserProfile%\Documents\My Games\Rocket League\TAGame\Demos`
- macOS: `$HOME/Library/Application Support/Rocket League/TAGame/Demos`
- Linux: `$HOME/.local/share/Rocket League/TAGame/Demos`

## Parse

Rattletrap can parse (decode) Rocket League replays and output them as JSON.

``` sh
> rattletrap decode input.replay output.json
# or
> rattletrap decode input.replay > output.json
# or
> rattletrap.decode < input.replay > output.json
```

The resulting JSON is minified, but extremely large. The output can be up to 50
times larger than the input.

## Generate

Rattletrap can also generate (encode) Rocket League replays from JSON files.

``` sh
> rattletrap encode input.json output.replay
# or
> rattletrap encode input.json > output.replay
# or
> rattletrap.encode < input.json > output.replay
```

If the JSON was generated by Rattletrap, the resulting replay should be
identical to the original.

## Modify

By inserting another program between parsing and generating, Rattletrap can be
used to modify replays.

``` sh
> rattletrap decode < original.replay |
  modify-replay-json |
  rattletrap encode > modified.replay
```

[Rattletrap]: https://github.com/tfausak/rattletrap
[Version badge]: https://www.stackage.org/package/rattletrap/badge/nightly?label=version
[version]: https://www.stackage.org/nightly/package/rattletrap
[Windows build badge]: https://ci.appveyor.com/api/projects/status/github/tfausak/rattletrap?branch=master&svg=true
[windows build]: https://ci.appveyor.com/project/TaylorFausak/rattletrap
[Build badge]: https://travis-ci.org/tfausak/rattletrap.svg?branch=master
[build]: https://travis-ci.org/tfausak/rattletrap
[Rocket League]: https://www.rocketleaguegame.com
[the latest release]: https://github.com/tfausak/rattletrap/releases/latest
[Stack]: https://docs.haskellstack.org/en/stable/README/