README: серверная часть, наш протокол и вход через лаунчер

README.md

@@ -8,10 +8,10 @@ with its own server, its own protocol and its own accounts.
 | Repository | License | What lives there |
 |---|---|---|
 | `rsx-client` | MIT | Loader, mod API, client hooks, deobfuscation tools |
-| `rsx-protocol` | MIT | Wire format, packet schemas, shared simulation library |
+| `rsx-protocol` | MIT | Wire format, packet schemas, shared vocabulary |
 | `rsx-plugin-api` | MIT | Interfaces for server-side content |
 | `rsx-server-core` | proprietary | Tick loop, world, entities, scaling |
-| `rsx-auth` | proprietary | Accounts, tokens, revocation |
+| `rsx-auth` | proprietary | The server's own accounts, used when there is no launcher |
 
 ## Target
 
@@ -56,6 +56,71 @@ both came out of this class of bug.
 The fork holds Mojang-derived code and is **not published**. What ships in the
 open repository is the loader, the mod API and the build tools.
 
+## The server
+
+The server owns the world. The client draws it and believes nothing.
+
+### The wire
+
+The protocol is ours, not the vanilla one. A vanilla 1.12.2 client and our
+server cannot talk to each other at all, and that is the point: the game is
+ours, so the wire is ours, and every packet in it is one we wrote down.
+
+The client's own game code is not rewritten. The client reads our packets and
+translates them into the game's, and the game does what it already knows how to
+do: build a world, spawn entities, draw them. The transport is ours; the
+renderer is the game's. The other direction is the same: the game says "the
+player moved" and "the player broke a block", and those two become our packets.
+
+### The world
+
+A chunk is sixteen by sixteen columns, two hundred and fifty six high, one byte
+per block. Generation is a pure function of the seed and the coordinates: no
+shared state, no `java.util.Random` carried between calls, no dependence on the
+order chunks are asked for. A chunk may be generated months after its
+neighbour, on another machine, and has to agree with it exactly, because a save
+file can only record what changed and not the terrain underneath it.
+
+Chunks are written one file per chunk, to a temporary name and moved into
+place, with a version and a checksum. A chunk that is half written when the
+power goes is a chunk the server refuses to load, rather than one that loads
+with half a world in it.
+
+### Who gets in
+
+The launcher is where accounts live: it has the passwords, the roles, the bans
+and the friends. The game server has none of that and does not want a second
+copy, so it asks the launcher whether a player is one of ours, and gets the ban
+list in the same answer.
+
+This is the part Yggdrasil does in vanilla, done with our own launcher. The
+launcher already logs the player in and already hands the game a name, a uuid
+and a token; the game hands that token to the server, and the server asks the
+launcher about it. The token is used once and dropped.
+
+The server's own accounts exist for a server of our own and for development.
+When a launcher is configured they are shut, because a server with two doors
+has no doors.
+
+```
+client                  game server                launcher
+  |  Hello                   |                        |
+  |------------------------->|                        |
+  |  HelloAck                |                        |
+  |<-------------------------|                        |
+  |  LauncherAuth            |                        |
+  |------------------------->|--- POST /auth/validate ->|
+  |                          |<-- {valid, reason} -----|
+  |  AuthAck                 |                        |
+  |<-------------------------|                        |
+  |  Login / LoginAck        |                        |
+  |==========================>|                        |
+  |  JoinWorld / WorldJoin   |                        |
+  |<==========================|                        |
+  |  ChunkData ...           |                        |
+  |<==========================|                        |
+```
+
 ## Modding
 
 Mods are jars with a descriptor at `META-INF/rsxmod.properties`:
@@ -114,10 +179,27 @@ rsx-client\scripts\test.ps1            # self test, 128 checks
 game-fork\scripts\prepare-game.ps1     # rebuild the fork from the vanilla jar
 game-fork\scripts\compile-game.ps1     # compile only, fast iteration
 rsx-client\scripts\run-game.ps1        # launch the client
+
+rsx-protocol\scripts\build.ps1        # dist\rsx-protocol.jar
+rsx-protocol\scripts\test.ps1         # 22 checks
+rsx-server-core\scripts\build.ps1     # dist\rsx-server-core.jar
+rsx-server-core\scripts\test.ps1      # 49 checks
+rsx-server-core\scripts\run-server.ps1
 ```
 
 Only a JDK is required. No Gradle, no network once the mappings are cached.
 
+### Running the server
+
+```
+run-server.ps1 --port 25565 --world world --seed 0
+run-server.ps1 --launcher-api https://launcher.example/api
+```
+
+`--launcher-api` points the server at the launcher's API. With it, the
+launcher decides who gets in and the server's own accounts are shut.
+`--allow-local-accounts` opens them again on purpose.
+
 ### Assets
 
 The client will not run without a real asset tree, and the launcher on this