Difference between revisions of "Engine/Structure"

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[[Category:Core]
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== The base (NMPR) ==
 
== The base (NMPR) ==
 
Everything is built on a small core, that was the original network multiplayer release of Minetest (call it NMPR; the 2010-10-24 version). Being around 10000 lines of code, it contains:
 
Everything is built on a small core, that was the original network multiplayer release of Minetest (call it NMPR; the 2010-10-24 version). Being around 10000 lines of code, it contains:

Revision as of 12:08, 19 January 2013

[[Category:Core]

The base (NMPR)

Everything is built on a small core, that was the original network multiplayer release of Minetest (call it NMPR; the 2010-10-24 version). Being around 10000 lines of code, it contains:

  • The Map: Voxel storage + lighting + rendering
  • The Client + Server logic
  • The Environment: Contains the map and the players, handles the simulation of the world
  • The main loop: Invokes the client, the server, the environment and the rendering.
  • A bunch of wrappers for OS-dependent things, and utilities.

As the current code still largely bases on the NMPR, it is useful to look at how it works.

Map (the voxels)

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Network protocol

The high-level network protocol of NMPR is delightfully simple. There are four commands for the server, and four commands for the client. Since this, a lot has been added and changed, but the basic idea stays the same.

Client -> Server

TOSERVER_GETBLOCK v3s16 p Ask the server to send the data of a block
TOSERVER_ADDNODE v3s16 p, MapNode node Inform the server of a placed node
TOSERVER_REMOVENODE v3s16 p, MapNode node Inform the server of a removed node
TOSERVER_PLAYERPOS v3s32 p*100, v3s32 speed*100 Inform the server of the positon of the local player

Server -> Client

TOCLIENT_BLOCKDATA v3s16 p, MapBlock data Send the content of a block (16x16x16 nodes)
TOCLIENT_ADDNODE v3s16 p, MapNode node Add a node
TOCLIENT_REMOVENODE v3s16 p, MapNode node Remove a node
TOCLIENT_PLAYERPOS foreach(player){
u16 player_id, v3s32 p*100, v3s32 speed*100}
Update players on client

Minetest uses it's own reliability layer on top of UDP. It isn't well documented at the moment, and thorough understanding of it isn't that important, so let's skip it as of now.

Environment

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Rendering

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