Everything old is new again!
CC's network message implementation has gone through several iterations:
- Originally network messages were implemented with a single class,
which held an packet id/type and and opaque blobs of data (as
string/int/byte/NBT arrays), and a big switch statement to decode and
process this data.
- In 42d3901ee3, we split the messages
into different classes all inheriting from NetworkMessage - this bit
we've stuck with ever since.
Each packet had a `getId(): int` method, which returned the
discriminator for this packet.
- However, getId() was only used when registering the packet, not when
sending, and so in ce0685c31f we
removed it, just passing in a constant integer at registration
instead.
- In 53abe5e56e, we made some relatively
minor changes to make the code more multi-loader/split-source
friendly. However, this meant when we finally came to add Fabric
support (8152f19b6e), we had to
re-implement a lot of Forge's network code.
In 1.20.4, Forge moves to a system much closer to Fabric's (and indeed,
Minecraft's own CustomPacketPayload), and so it makes sense to adapt to
that now. As such, we:
- Add a new MessageType interface. This is implemented by the
loader-specific modules, and holds whatever information is needed to
register the packet (e.g. discriminator, reader function).
- Each NetworkMessage now has a type(): MessageType<?> function. This
is used by the Fabric networking code (and for NeoForge's on 1.20.4)
instead of a class lookup.
- NetworkMessages now creates/stores these MessageType<T>s (much like
we'd do for registries), and provides getters for the
clientbound/serverbound messages. Mod initialisers then call these
getters to register packets.
- For Forge, this is relatively unchanged. For Fabric, we now
`FabricPacket`s.
This adds SPDX license headers to all source code files, following the
REUSE[1] specification. This does not include any asset files (such as
generated JSON files, or textures). While REUSE does support doing so
with ".license" files, for now we define these licences using the
.reuse/dep5 file.
[1]: https://reuse.software/
After several weeks of carefully arranging ribbons, we pull the string
and end up with, ... a bit of a messy bow. There were still some things
I'd missed.
- Split the mod into a common (vanilla-only) project and Forge-specific
project. This gives us room to add Fabric support later on.
- Split the project into main/client source sets. This is not currently
statically checked: we'll do that soon.
- Rename block/item/tile entities to use suffixes rather than prefixes.
Jonathan Coates