Sprite sheet

UniStores can have a sprite sheet to have icons for the apps, this need to be in .t3x format which can be generated with devkitPro's tex3ds.

To make the .t3x file you will need a .t3s file and image files. The .t3s should contain something like:

--atlas -f rgba -z auto

0.png
1.png

Where 0.png and 1.png are app icons in the same directory. The app icons should be up to 48x48 and the order they are in the .t3s file will be the order for icon_index in their info section.

You can then generate the t3x by running:

tex3ds -i path/to/file.t3s -o path/to/file.t3x

Important things to know:

• The first icon_index is zero.

• Only PNG file format can be used.

• An atlas map needs to be fit on an 1024x1024 plane, so the maximum number of icons on one spritesheet is limited. Some icon sizes and the formula and the corresponding number of icons are in the following table:

  Icon size	Max number of icons
  16x16	4096
  32*32	1024
  48*48	442
  X*Y	(1024 modulo X)*(1024 modulo Y)

• Instead of downsizing the icons, you can use multiple spritesheets too. (see sheet_index)

Sample Python code to convert any graphics to icons:

#Image resize to icon size with keeping aspect ratio and convert to PNG format
import PIL
from PIL import Image

#the wanted iconsize is 48x48
iconsize = (48,48)

img = Image.open("something.jpg")
img.thumbnail(iconsize)
img.save("something.png")
#Note: Python knows from the file extension that the image needs to be converted to .PNG format