buildat/design.txt

Buildat
=======
A Minecraft clone with vast extendability.

License: MIT

Client
------
Built using Polycode C++.

Module code is transfered from the server and run in a safe Lua sandbox.

Server
------
Built using C++ with most functionality in RCC++.

C++ modules can interface with each other by using Cereal.

Module structure
----------------
module
|-- client
|   `-- init.lua  << Client-side code
|-- server
|   `-- init.cpp  << Server-side code
|-- include
|   `-- api.h     << Structures for interfacing between modules
`-- data
    `-- media.png << Data files

Module behavior
---------------
No script or data transfer to the client is initiated by the core. The
module/client/init.lua file is a convention followed by the built-in modules.

Modules can be unloaded at runtime. Handling of client-side state is left up to
the C++ modules themselves.

The first module to be loaded is called __loader. It loads all other modules.

C++ modules can use the core/ and interface/ headers. Everything else is
considered unstable.

C++ modules are run in threads, and everything they can officially access is
thread-safe.

C++ modules can provide direct library functionality inlined in their include/
files. They cannot export any internally defined functions directly, but they
can provide convenience wrappers for event-based interfaces.

Startup sequence and what the module should do:
- constructor        : Initialize everything you can here
- init()             : Subscribe to events
- "core:start" event : Start doing whatever the module wants to actively do

Network protocol
----------------
(Type, length, data) tuples on TCP. In the future TLS can be taken into use. A
name->type registry is used for determining numeric packet types.

Data is freeform. Types 0...100 are reserved for initialization.

Core uses cereal's portable binary serialization.