README.md

Variation Injection

In the new playable pico update to the base game (0.5.0), a new merge logic for JSON files was introduced, which allows you to inject changes into existing JSON files without replacing them, but in a much more flexable way than was previously possible. One of the new things you can do with the new JSON Patch merge logic is add members to existing arrays in a JSON file. This means that the variation injection system in this framework is now deprecated, and you should use the new JSON Patch merge logic to inject your variations into existing songs. You can keep reading if you want to know how to use this new feature for variation injection, but if you want to know more about using JSON Patch merge logic, you can check out the Merging into JSON Files section in the Friday Night Funkin' Modding Documentation.

How to do variation injection the OFFICIAL way using JSON Patch merge logic

This method uses merge logic, so you'll need to create a _merge folder in your mod's root folder, and from there, you can create a folder structure that matches the structure of the file you want to inject your variation into. So if you want to inject your variation into the metadata file of a song, you'll need to create a folder structure that matches the structure of the metadata file, which is data/songs/[song ID]/[song ID]-metadata.json. Inside the JSON file, you'll need to write a JSON Patch document to tell Polymod to add your variation to the song's playData.songVariations array. Here's an example of how you can do this:

[
    {
        "op": "add",
        "path": "/playData/songVariations/-",
        "value": "your-variation-name"
    }
]

And this is how you can inject your variation to a song using the new JSON Patch merge logic. If you want to inject your variation to multiple songs, you can repeat the same process for each song you want to inject your variation to.

Original Instructions (deprecated):

Instead of replacing existing songs' default metadata and chart files, this framework allows you to inject your variation into existing songs using polymod's append logic. This way, you can add your variation to an existing song without replacing its files, and multiple mods can add their variations to the same song without conflicting with yours.

To inject your variation into existing songs, you'll need to put an empty .txt file in this folder, with its name as your variation's name, and then add another .txt file with the same name to the same place, but through the _append folder, and fill that file with the song ids you want to inject your variation to separated by new lines. This method utlizes polymod's append logic, which means every variation injection file you make will be appendable by other mods.

Note

You need to have the variation chart and metadata files placed in the songs folder for this to work (NOT through the _append folder). However, just remember not to replace the default ones, because this is the action variation injection was meant to replace.

Examples

This will be located at mods/[mod's name]/_append/data/UD/vari-injections/[variation name].txt:

bopeebo
fresh
dadbattle

This will be located at mods/[mod's name]/data/UD/vari-injections/[variation name].txt:

// Empty file
// and yes, you can actually put comments in here, but only at the start of the line
// You can also have empty lines, like this one:

// You see, empty lines are allowed and are ignored.

The final file will look like this:

// Empty file
// and yes, you can actually put comments in here, but only at the start of the line
// You can also have empty lines, like this one:

// You see, empty lines are allowed and are ignored.
bopeebo
fresh
dadbattle

Then, another mod could do this again with a different variation name, but with the same songs, and both variations will appear in the game. Another mod might also do this with the same variation and different songs. For example:

This will be located at mods/[mod's name]/_append/data/UD/vari-injections/[variation name].txt:

spookeez
south
monster

This will be located at mods/[mod's name]/data/UD/vari-injections/[variation name].txt:

// Empty file
// It doesn't matter if you put different comments here
// Just don't put anything important in here, because it might get replaced

Now, the final file will look like this:

// Empty file
// It doesn't matter if you put different comments here
// Just don't put anything important in here, because it might get replaced
bopeebo
fresh
dadbattle
spookeez
south
monster

As you can see, the empty file's only purpose should be to form a base for polymod to append to, and that's why only append logic should be used to make the actual list of songs to inject the variation to.