https://github.com/hexeption/fastpack
Texture atlas packer written in Rust. Native GUI as the primary interface, plus a full CLI. Designed as an open-source replacement for TexturePacker.
https://github.com/hexeption/fastpack
game-development rust sprite-packer texture-atlas
Last synced: 4 months ago
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Texture atlas packer written in Rust. Native GUI as the primary interface, plus a full CLI. Designed as an open-source replacement for TexturePacker.
- Host: GitHub
- URL: https://github.com/hexeption/fastpack
- Owner: Hexeption
- License: mit
- Created: 2026-02-24T06:11:17.000Z (4 months ago)
- Default Branch: master
- Last Pushed: 2026-02-28T14:22:51.000Z (4 months ago)
- Last Synced: 2026-02-28T19:21:47.041Z (4 months ago)
- Topics: game-development, rust, sprite-packer, texture-atlas
- Language: Rust
- Homepage:
- Size: 1.7 MB
- Stars: 0
- Watchers: 0
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# FastPack
[](https://crates.io/crates/fastpack)
[](https://github.com/Hexeption/FastPack/actions/workflows/ci.yml)
[](https://www.rust-lang.org)
Texture atlas packer written in Rust. Native GUI as the primary interface, plus a full CLI and TUI. Designed as an open-source replacement for TexturePacker.
## Features
**Packing**
- MaxRects (5 heuristics), Grid, and Basic strip algorithms
- Trim modes: None, Trim, Crop, CropKeepPos, Polygon (convex hull)
- Extrusion, rotation, nine-patch metadata, pivot points
- Alias detection — deduplicates pixel-identical sprites
- Multipack — overflow sprites across multiple sheets
- Multi-resolution scale variants with per-variant suffix
**Export**
- JSON Hash, JSON Array, Phaser 3, PixiJS
- PNG (oxipng lossless), JPEG (mozjpeg), WebP, lossy PNG (imagequant)
**GUI**
- Real-time atlas preview
- Collapsible sprite tree with thumbnail previews
- Watch mode — repacks on file change
- `.fpsheet` project files (TOML)
- Multi-language UI
## Install
Download the installer for your platform from the [releases page](https://github.com/Hexeption/FastPack/releases):
- **Windows** — `fastpack-windows-x86_64.msi`
- **macOS (Apple Silicon)** — `fastpack-macos-aarch64.dmg`
- **macOS (Intel)** — `fastpack-macos-x86_64.dmg`
- **Linux** — `fastpack-linux-x86_64.tar.gz`
Or install from crates.io:
```sh
cargo install fastpack
```
## Usage
```sh
# Open the GUI (default when no subcommand is given)
fastpack
# Pack a directory of sprites
fastpack pack sprites/ --output output/
# Pack with options
fastpack pack sprites/ --output output/ \
--max-width 2048 --max-height 2048 \
--trim-mode trim \
--data-format phaser3 \
--allow-rotation
# Load settings from a project file
fastpack pack --project atlas.fpsheet
# Watch for changes and repack automatically
fastpack watch sprites/ --output output/
# Split an atlas back into individual sprites
fastpack split atlas.png atlas.json --output-dir sprites/
# Generate a default project file
fastpack init --output atlas.fpsheet
```
## Project File
Settings live in a `.fpsheet` TOML file:
```toml
[meta]
version = "1"
[output]
name = "atlas"
directory = "output/"
texture_format = "png"
pixel_format = "rgba8888"
data_format = "json_hash"
quality = 95
[layout]
max_width = 4096
max_height = 4096
size_constraint = "pot"
force_square = false
allow_rotation = true
pack_mode = "good"
border_padding = 2
shape_padding = 2
[sprites]
trim_mode = "trim"
trim_threshold = 1
extrude = 0
detect_aliases = true
[algorithm]
type = "max_rects"
heuristic = "best_short_side_fit"
[[variants]]
scale = 1.0
suffix = "@1x"
mode = "smooth"
[[sources]]
path = "sprites/"
filter = "**/*.png"
```
## Export Formats
`data_format` in the project file or `--data-format` on the CLI accepts:
- `json_hash` — TexturePacker-compatible JSON with frames as an object keyed by sprite ID. Default.
- `json_array` — Same structure but frames as an array, each entry with a `filename` field.
- `phaser3` — Single JSON file with a `textures` array. Compatible with `scene.load.multiatlas()`.
- `pixijs` — JSON Hash format compatible with PixiJS sprite sheet loaders.
## Building from Source
Requires Rust 1.85+.
```sh
git clone https://github.com/Hexeption/FastPack
cd FastPack
cargo build --release -p fastpack
```
The binary is at `target/release/fastpack`.
## License
Licensed under [MIT](LICENSE).