# Introduction

Crunch is an [open source](https://lab.lcr.gr/microhacks/crunch), GPL-3.0 licensed command line tool written in Rust for manipulating assets, 
designed to complement a game development asset pipeline. Commands can either be executed directly, or can
be executed via [pipeline files](pipelines/file_format.md).

## Quick Installation

If you're using Linux or Windows, you can download the pre-built binaries, copy them to your path and get going:

- [Latest version for Windows](https://lab.lcr.gr/microhacks/crunch/-/jobs/artifacts/trunk/raw/target/x86_64-pc-windows-gnu/crunch.exe?job=build-windows)
- [Latest version for Linux](https://lab.lcr.gr/microhacks/crunch/-/jobs/artifacts/trunk/raw/target/release/crunch?job=build-linux)

Check the [installation](getting_started/installation.md) page for more ways of sourcing your version of Crunch, including 
installing from source on other platforms.

## Basic Usage

After you've installed the binary, you can use the `crunch` command to start manipulating assets. Check out the 
help for a given command with `crunch <command> --help`, or by checking the link in the sidebar that correlates to the
command you want to run.

```text
Usage: crunch <COMMAND>

Commands:
  rotate    Rotate an image clockwise by the given degree
  extrude   Take each tile in an image and expand its borders by a given amount. Optionally fill with nearby pixels instead of empty space
  palette   Create a palette file containing every distinct colour from the input image
  scale     Resize an image by a scale factor
  flip      Flip an image along one or more axis
  remap     Convert the colour space of an image to that of a given palette file
  pipeline  Execute a predefined pipeline
  reduce    Limit the number of colours by quantity or threshold
  split     Take a spritesheet and split into individual sprites, skipping empty space
  help      Print this message or the help of the given subcommand(s)

Options:
  -h, --help     Print help
  -V, --version  Print version
```

### Updating from 0.4 to 0.5

`0.5.0` contains a breaking change to the argument order for commands. From `0.5` onwards, the command being
executed is now specified **before** the input and output file paths. This is because some commands don't use
both an input and an output, causing version `0.4` and lower to require a dummy value in those locations.

For Example:

- **0.4**: `crunch ./myimage.png ./myimage-flipped.png flip -d both`
- **0.5**: `crunch flip -d both ./myimage.png ./myimage-flipped.png`