mirror of
https://github.com/ViaVersion/Mappings.git
synced 2024-11-19 11:35:23 +01:00
109 lines
4.7 KiB
Markdown
109 lines
4.7 KiB
Markdown
# Mappings
|
|
|
|
Generates and compiles mapping files for Via*. Current mapping files can be found in the `mappings/` directory.
|
|
|
|
## Generating json mapping files for a Minecraft version
|
|
|
|
Compile the project using `mvn clean build` and put the jar in some directory, ideally the project root.
|
|
|
|
Then run the jar with:
|
|
|
|
```
|
|
java -jar MappingsGenerator.jar <path to server jar> <version>
|
|
```
|
|
|
|
The mapping file will then be generated in the `mappings/` directory.
|
|
|
|
## Compiling json mapping files into compact nbt files
|
|
|
|
If you want to generate the compact mapping files with already present json files, you can also trigger the optimizer on
|
|
its own by starting the `MappingsOptimizer` class with the two arguments flipped:
|
|
|
|
```
|
|
java -cp MappingsGenerator.jar com.viaversion.mappingsgenerator.MappingsOptimizer <from version> <to version>
|
|
```
|
|
|
|
### Optional arguments
|
|
|
|
Optional arguments must follow the two version arguments.
|
|
|
|
* `--generateDiffStubs` to generate empty diff files for missing mappings
|
|
* `--keepUnknownFields` to keep non-standard fields from json mappings in the compact files
|
|
|
|
## Json format
|
|
|
|
The json files contain a number of Minecraft registries in form of json arrays, where the index corresponds to the id of
|
|
the entry.
|
|
|
|
Diff files for either ViaVersion or ViaBackwards then contain additional entries for changed identifiers, either in form
|
|
of string→string or int→string mappings. These files need to be manually filled. If any such entries are required, the
|
|
optimizer will give a warning with the missing keys.
|
|
|
|
Json mapping files are found in the `mapping/` directory and are named `mapping-<version>.json`. Files containing
|
|
diff-mappings for added or removed identifiers between versions must be named `mapping-<from>to<to>.json` and put into
|
|
the `mapping/diff/` directory.
|
|
|
|
## Compact format
|
|
|
|
Compact files are always saved as [NBT](https://minecraft.fandom.com/wiki/NBT_format). ViaVersion uses its
|
|
own [OpenNBT](https://github.com/ViaVersion/OpenNBT) as the NBT reader/writer. Compact files are found in the
|
|
`output/` directory and subdirectories.
|
|
|
|
### Identifier files
|
|
|
|
Next to a standardized compact format, there are extra files per version to store the identifier arrays of certain
|
|
registries, as their full keys might be required. These files simply contain any number of json arrays.
|
|
|
|
### Mapping files
|
|
|
|
Each mapping file contains a `v` int tag with the format version, currently being `1`.
|
|
|
|
In each mapping file, a number of extra objects may be contained, such as string→string mappings for sounds. Most other
|
|
parts (including blockstates, blocks, items, blockentities, enchantments, paintings, entities, particles, argumenttypes,
|
|
and statistics) are stored as compound tags, containing:
|
|
|
|
* `id` (byte tag) determining the storage type as defined below
|
|
* `size` (int tag) the number of unmapped entries in the registry
|
|
* `mappedSize` (int tag) the number of mapped entries in the registry
|
|
|
|
The rest of the content depends on the storage type, each resulting in vastly different storage sizes depending on the
|
|
number and distribution of id changes, used to make the mapping files about as small as possible.
|
|
|
|
### Direct value storage
|
|
|
|
The direct storage simply stores an array of ints exactly as they can be used in the protocol.
|
|
|
|
* `id` (byte tag) is `0`
|
|
* `val` (int array tag) contains the mapped ids, where their array index corresponds to the unmapped id
|
|
|
|
### Changed value storage
|
|
|
|
The changed value storage stores two int arrays: One containing the changed unmapped ids, and one their corresponding
|
|
mapped ids in a simple int→int mapping over the two arrays.
|
|
|
|
* `id` (byte tag) is `1`
|
|
* `at` (int array tag) contains the unmapped ids that have been changed
|
|
* `val` (int array tag) contains the mapped ids, indexed by the same index as the unmapped id in `at`
|
|
* Optional: `nofill` (byte tag): Unless present, all ids between the ones found in `at` are mapped to their identity
|
|
|
|
### Shifted value storage
|
|
|
|
The shifted value storage stores two int arrays: One containing the unmapped ids that end a sequence of mapped ids. For
|
|
an index `i`, all unmapped ids between `at[i] + sequence` (inclusive) and `at[i + 1]` (exclusive) are mapped
|
|
to `to[i] + sequence`.
|
|
|
|
* `id` (byte tag) is `2`
|
|
* `at` (int array tag) contains the unmapped ids, where their mapped is is *not* simply the last mapped id + 1
|
|
* `to` (int array tag) contains the mapped ids, indexed by the same index as the unmapped id in `at`
|
|
|
|
### Identity storage
|
|
|
|
The identity storage signifies that every id between `0` and `size` is mapped to itself. This is sometimes used over
|
|
simply leaving out the entry to make sure ids stay in bounds.
|
|
|
|
* `id` (byte tag) is `3`
|
|
|
|
## License
|
|
|
|
The Java and Python code is licensed under the GNU GPL v3 license. The files under `mappings/` are free to copy, use,
|
|
and expand upon in whatever way you like. |