Use YAML to describe your sprite sheet and give your sprites names. go-spritesheet will take care of the math for each sprite location, as well as provide a map for easy sprite lookups.

go-spritesheet pairs nicely with a library like ebiten.

// Load the config
sheet, err := spritesheet.OpenAndRead("spritesheet.yml")

if err != nil {
    panic(err)
}

// Load the image
img, _, err := ebitenutil.NewImageFromFile(sheet.Image)

if err != nil {
    panic(err)
}

sprites := sheet.Sprites()

// Get the sprite
s := img.SubImage(sprites["mySprite"].Rect())

image: hero.png

rows: 3
cols: 4
size: 16

sprites: [
    idle_1, idle_2, idle_3, idle_4,
    run_1, run_2, run_3, run_4,
    atk_1, atk_2, atk_3, atk_4
]

• image: The path to your sprite sheet image.
• rows: The number of rows in the sprite sheet.
• cols: The number of columns in the sprite sheet.
• size: The size of each sprite, in pixels.
• sprites: A list of sprite names.
  • Names must be unique.
  • Must contain 0 to n entries, where n is rows*cols
  • Using an underscore _ skips the sprite. Useful if you have "holes" in your sprite sheet.