Polymod Tutorial
Create a folder in the mods folder and rename it to whatever you want.
Doing this manually is not a problem, but it would be faster if you copy-and-pasted the Template in the mods folder.
The information for a mod is stored in two files. Those two files are _polymod_icon.png and _polymod_meta.json.
Additionally, if you want to make a modpack, the mod info is also stored in _polymod_pack.txt.
In _polymod_meta.json, you can define the mod name, the name of the author, etc.
Example:
Now, about _polymod_icon.png, it's just a simple .png icon for the mod. Just keep in mind that whatever image it is, it will always be squished into a 150 by 150 resolution. So a 1:1 aspect ratio is recommended for your image.
As for _polymod_pack.txt, This is what the new ModCore.hx takes care of.
To create a modpack, add the following text to a .txt file:
foo:1.0.0,bar:1.*.*,abc,xyz
It searches for, and loads the mods with the IDs foo, bar, abc, and xyz, in that order. It will fail to get any mods that fail the version check (foo must be exactly 1.0.0 while bar allows any 1.x version) and only load the mods which don’t fail.
When you're done with that, you're basically good to go!
Here's an example mod by Master Eric » here «