spritepacker

🧩 SpritePacker

SpritePacker is a 2D sprite sheet packing tool designed for game developers.

🛠 Usage

CLI Command

go install github.com/91xusir/spritepacker@latest

spritepacker -help

🛠️ Packing Options

🛠️ Unpacking Options

📦 Examples

# Pack all images in ./sprites with default settings
spritepacker -input ./sprites -output ./atlases

# Custom atlas size, padding, and enable rotation
spritepacker -input ./sprites -maxw 1024 -maxh 1024 -trim -

# Unpack atlas using atlas.json
spritepacker -unpack ./atlases/atlas.json -output ./unpacked

🧪 API

go get -u github.com/91xusir/spritepacker

Example Usage:

package main

import (
	"github.com/91xusir/spritepacker/pack"
	"encoding/json"
	"os"
	"path/filepath"
)

func Pack() {
	// Step 1: Create packing options and set the maximum atlas size to 4096x4096
	options, _ := (pack.NewOptions().
		MaxSize(4096, 4096)).
	    Trim(true).
		Sort(true).
		Padding(-1).
		//AllowRotate(true).
		//Algorithm(pack.AlgoSkyline).
		//Heuristic(pack.ContactPointFit).
		//AutoSize(true).
		//PowerOfTwo(true).
		Validate()	// Optional: Validate the options. If invalid, an error will be returned.

	// Step 2: Create the sprite packer using the configured options
	spritePacker := pack.NewPacker(options)

	// Step 3: Collect all sprite image paths
	spriteImgPaths, _ := pack.GetFilesInDirectory("input")

	// Step 4: Pack all sprite images and generate atlas metadata and images
	spriteAtlasInfo, atlasImages, _ := spritePacker.PackSprites(spriteImgPaths)

	// Step 5: Save each atlas image to the "output" directory
	for i := range atlasImages {
		outputPath := filepath.Join("output", spriteAtlasInfo.Atlases[i].Name)
		_ = pack.SaveImg(outputPath, atlasImages[i], pack.PNG, pack.WithCLV(pack.DefaultCompression))
	}
	// Step 6: Save the atlas metadata as a JSON file
	jsonBytes, _ := json.MarshalIndent(spriteAtlasInfo, "", "  ")
	_ = os.WriteFile("output/atlas.json", jsonBytes, os.ModePerm)

}

func Unpack() {
	// default output and atlas images path is the same as the atlas.json path
	// if you want to change this, you can use the following code:
	// pack.UnpackSprites("output/atlas.json", pack.WithAtlasImgPath("output"), pack.WithOutputPath("output"))
	err := pack.UnpackSprites("output/atlas.json")
	if err != nil {
		return
	}
}

✅ TODO List

• Custom output format using Go templates
• more format support
• GUI