SpriteAtlas resizing via script

Hi!

I'm trying make a routine for automating the creation of SpriteAtlas variants. The imagined routine is:
- Duplicate a master atlas.
- Set duplicated atlas as variant of master.
- Set scale on duplicated atlas.

Duplicating an asset is easy, but accessing anything of the SpriteAtlas is not. From what I can see of the documentation, SpriteAtlas is completely sealed off.

As an alternative approach, I looked into the Sprite Packer to see if I could pack a new atlas, but the packer is sealed off too.

I could probably do all of this via reflection, but I suspect that would break easily and cause more work in the future.

Has anyone tried anything similar and have any valuable lessons to share?

-
Thomas

 

I ended up using reflection. It'll probably break easily, so I have to add code to throw warnings when it does.

This is the basics of how I solved it:

Code (CSharp):

1.  
2. SpriteAtlas masterAtlas = AssetDatabase.LoadAssetAtPath<SpriteAtlas>(masterPath);
3. SpriteAtlas variantAtlas = AssetDatabase.LoadAssetAtPath<SpriteAtlas>(variantPath);
4.  
5. Assembly editorAssembly = Assembly.GetAssembly(typeof(Editor));
6. Type spriteAtlasExt = editorAssembly.GetType("UnityEditor.U2D.SpriteAtlasExtensions");
7. Type spriteAtlasUtil = editorAssembly.GetType("UnityEditor.U2D.SpriteAtlasUtility");
8.  
9. spriteAtlasExt
10.     .GetMethod("SetIsVariant")
11.     .Invoke(variantAtlas, new object[] { variantAtlas, true });
12.  
13. spriteAtlasExt
14.     .GetMethod("SetMasterAtlas")
15.     .Invoke(variantAtlas, new object[] { variantAtlas, masterAtlas });
16.  
17. spriteAtlasExt
18.     .GetMethod("SetVariantMultiplier")
19.     .Invoke(variantAtlas, new object[] { variantAtlas, scale });
20.  
21. spriteAtlasUtil
22.     .GetMethod("PackAtlases", BindingFlags.Static | BindingFlags.NonPublic)
23.     .Invoke(null, new object[] {
24.         new SpriteAtlas[] { variantAtlas },
25.         EditorUserBuildSettings.activeBuildTarget
26.     });
27.  

You can have a look at the source code for the UnityEngine.U2D namespace at https://github.com/MattRix/UnityDec...3c81bc0910cef177c/UnityEditor/UnityEditor.U2D