Good Asset Fetcher

Library mod for StationAPI that provides an interface for other mods to fetch resources from official Mojang jars on the fly when starting the game; this allows mods to utilise the game's assets without incurring license violations.

Currently only supports clientside assets (not datapacks).

Requirements

• Minecraft Beta 1.7.3
• Babric
• StationAPI
• Fabric Language Kotlin

Usage (for developers)

1. Import pw.tmpim.mygoodmods:good-asset-fetcher from Maven (see the version badge above for the latest version):

   repositories {
     maven("https://repo.lem.sh/releases") {
       name = "Lemmmy Repo"
       content {
         includeGroupAndSubgroups("sh.lem")
         includeGroupAndSubgroups("pw.tmpim")
       }
     }
   }
   
   dependencies {
     modImplementation("pw.tmpim.mygoodmods:good-asset-fetcher:1.0.4")
   }
   

2. Register a client-only endpoint for your mod in fabric.mod.json if you don't already have one:

     {
       "entrypoints": {
         "stationapi:event_bus_client": "com.example.yourmod.ExampleModClientListener"
       },  
       "depends": {
         "good-asset-fetcher": "1.x"
       }
     }  
   

3. Listen to the GoodAssetFetcherRegistryEvent and call addResourceFile, addBlock, or addItem:

   public class ExampleEventListener {
       @Entrypoint.Namespace  
       public static Namespace NAMESPACE;
   
       @EventListener  
       public void onRegisterGoodAssets(GoodAssetFetcherRegistryEvent event) {  
           // shorthands for blocks and items:
           event.addBlock(NAMESPACE, "1.12.2", "redstone_block");
           event.addItem(NAMESPACE, "1.12.2", "stick");
   
           // load an asset by full path:
           event.addResourceFile(NAMESPACE, "1.12.2", "assets/minecraft/textures/blocks/stone.png");
       }
   }
   

4. Use the textures under assets/your-mod/stationapi/textures/block/stone.png:

   {
     "parent": "minecraft:block/cube_all",
     "textures": {
       "all": "your-mod:block/stone"
     }
   }
   

How it works

During the game's init phase, before resource packs are loaded, Good Asset Fetcher loads the version manifest from the Minecraft Launcher to get a listing of all game versions. This listing is then cached indefinitely at .minecraft/mods/good-asset-fetcher/asset-cache/versionManifest-$modVersion.json.

Then, GoodAssetFetcherRegistryEvent is called to fetch the resource definitions for every mod. Mods may request to fetch assets from (almost?) any version of the game.

When resource packs are loaded, the mod injects its own dynamic resource pack at runtime. When this is first loaded during a session, it checks for any missing assets in the mod's cache directory, .minecraft/mods/good-asset-fetcher/asset-cache.

Armed with the knowledge of all the missing assets and their associated game versions, good-asset-fetcher will download each version's manifest and jar in-memory, validate the hash, and extract the required files. This process is done during resource pack load, so it will block the game the first time it happens, and then ideally remain cached permanently in .minecraft/mods/good-asset-fetcher/asset-cache.

Since StationAPI stores assets in a slightly different location to most versions of vanilla, the mod performs the following path conversions to the destination file path automatically:

Source path	Cached path
assets/minecraft/textures/blocks	assets/${namespace}/stationapi/textures/block
assets/minecraft/textures/items	assets/${namespace}/stationapi/textures/item

If your use case is not properly covered, the addResourceFile(Namespace namespace, String gameVersion, String sourcePath, String destPath) overload is available for you to specify your own destination path. Note, however, that it will still go through the same string replacements as above.

License

This mod is licensed under the MIT license.