SpriteStitcher

SpriteStitcher is a lightweight and simple command-line tool that stitches multiple PNG images into a single sprite atlas, or unpacks a sprite atlas back into its individual images.

It's written in C# (.NET 8), portable, and built with game developers and pixel artists in mind.

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Features

• Stitch PNG images into an optimized atlas using skyline-packing.
• Unstitch existing atlases back into individual images.
• JSON metadata for use in engines or your own tools.

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Usage

Stitch

SpriteStitcher.exe <folder> --stitch <name> [--padding <n - default 2>]

Stitch takes every .png file within the specified directory (but not subdirectories!) and combines them all into a single .png image, with the specified padding of n pixels between each image.

Example:

SpriteStitcher.exe C:\MySprites --stitch "my_atlas.png" --padding 4

This command will:

• Create a subdirectory called stitched within C:\MySprites to store the atlas
• Stitch all .png files together into an atlas called my_atlas.png, with a padding of 4 pixels between each sprite.
• Generate the relevant metadata within my_atlas.json.

Unstitch

SpriteStitcher.exe <folder> --unstitch <atlas.png>

Unstitch takes in a PNG of an atlas and, using its metadata, separates it into its original images.

Example:

SpriteStitcher.exe D:\MySprites\stitched --unstitch my_atlas.png

This command will:

• Create the subdirectory unstitched.
• Parse my_atlas.json to process each image within the atlas
• Extract all images to unstitched
• Ask to delete the atlas and metadata

JSON Format

Each atlas is accompanied by a .json file in the following format:

{
  "image": "atlas.png",
  "sprites": {
    "sprite1.png": { "x": 0, "y": 0, "width": 32, "height": 32 },
    ...
  }
}

Build

You do not need to build SpriteStitcher directly from the source. Just go to Releases and download the latest version!

About

I made SpriteStitcher as part of my effort to familiarize myself with C#. That being said, it also fills a large gap within my workflow and I'd love to see it flourish. So, Pull Requests, forks, and anything in between is welcome! If you'd like SpriteStitcher to have a certain feature please do not hesitate to open up an issue or a PR!

Credits: White Tower Games / Christos Maragkos: Programming and Testing

Notes

• (Currently) assumes non-rotated, top-left anchored sprites.
• Atlas max width is set to 4096.
• Only .png images are supported.