Loot Table Modifier

Allows datapacks (and thus mods as well) to add to loot tables, instead of just overwriting them.

Also provides a datagen provider for creating loot table modifiers in mods.

A modifier json file includes two components:

1. "modifies" - string or array, which defines the loot tables to modify. For example "minecraft:entities/creeper" or "minecraft:chests/abandoned_mineshaft"
2. "pools" - array of loot pools. This works exactly the same as the "pools" in a vanilla loot table, thus you can generate a loot table online with a tool like misode.github.io and copy over the "pools" from the generated json. (I may fork it and add a generator for specifically this mod in the future™)
   An example json file:

// example_pack/data/example/loot-table-modifier/loot_modifier/drop_tnt.json
{
    // Can also be a single identifier without an array
    // "modifies": "minecraft:entities/creeper",
    "modifies": [
        "minecraft:entities/creeper",
        "minecraft:entities/zombie"
    ],
    "pools": [
        {
            "bonus_rolls": 0.0,
            "entries": [
                {
                    "type": "minecraft:item",
                    "functions": [
                        {
                            "add": false,
                            "count": {
                                "type": "minecraft:uniform",
                                "max": 1.0,
                                "min": 0.0
                            },
                            "function": "minecraft:set_count"
                        }
                    ],
                    "name": "minecraft:tnt"
                }
            ],
            "rolls": 1.0
        }
    ]
}

Depend on inside mod:

repositories {
    // ...
    maven {
        name = "OffsetMods538"
        url = "https://maven.offsetmonkey538.top/releases"
        content {
            includeGroup "top.offsetmonkey538.loottablemodifier"
        }
    }
}


dependencies {
    // ...
    modImplementation "top.offsetmonkey538.loottablemodifier:loot-table-modifier:1.0.1+1.21.1"
}